Molecular Recognition Laboratorium: Difference between revisions

From OpenWetWare
Jump to navigationJump to search
 
(32 intermediate revisions by the same user not shown)
Line 1: Line 1:
<div style="padding: 10px; color: #ffffff; background-color: #000; width: 600px">
[[Image:MolRec-Logo.jpg|600px]]
[[Image:MolRec-Logo.jpg|600px]]
<div style="padding: 10px; color: #000; background-color: #CEF2E0; width: 600px">




Line 9: Line 10:
CHARITÉ - UNIVERSITÄTSMEDIZIN BERLIN<br>
CHARITÉ - UNIVERSITÄTSMEDIZIN BERLIN<br>
{{hide|
{{hide|
[[Image:Molrec placeholder.png|167px|right]]
[[Image:Molrec placeholder.png|112px|right]]
  Hessische Str. 3-4
  Hessische Str. 3-4
  D-10115 Berlin, Germany
  D-10115 Berlin, Germany
Line 22: Line 23:
</div><br>
</div><br>
==Group Leader==
==Group Leader==
<div style="padding: 10px; color: #ffffff; background-color: #000; width: 600px">
<div style="padding: 10px; color: #000; background-color: #CEF2E0; width: 600px">
Rudolf Volkmer  {{hide|
Rudolf Volkmer  {{hide|
[[Image:Molrec placeholder.png|130px|right]]
[[Image:Molrec placeholder.png|112px|right]]
  Tel.: +49 30 450 524 267
  Tel.: +49 30 450 524 267
  Fax: +49 30 450 524 942
  Fax: +49 30 450 524 942
Line 35: Line 36:


==Group Members==
==Group Members==
<div style="padding: 10px; color: #ffffff; background-color: #000; width: 600px">
<div style="padding: 10px; color: #000; background-color: #CEF2E0; width: 600px">
*Bernhard Aÿ, Postdoc {{hide|
*Magdalena Czuban, Dipl. Biol. {{hide|
[[Image:Molrec placeholder.png|130px|right]]
[[Image:Molrec placeholder.png|112px|right]]
  Tel.: +49 30 450 524 254
  Tel.: +49 30 450 xxx xxx
  Fax: +49 30 450 524 942
  Fax: +49 30 450 524 942
  E-Mail: bernhard.giese(at)charite.de
  E-Mail: x(at)charite.de
}}
}}
*Prisca Boisguérin, Postdoc {{hide|
*Mercedes Gonzáles, Studentin {{hide|
[[Image:Molrec placeholder.png|130px|right]]
[[Image:Molrec placeholder.png|112px|right]]
  Tel.: +49 30 450 524 254
  Tel.: +49 30 450 xxx xxx
  Fax: +49 30 450 524 942
  Fax: +49 30 450 524 942
  E-Mail: prisca.boisguerin(at)charite.de
  E-Mail: x(at)charite.de
}}
}}
*Zerrin Fidan, Doktorandin {{hide|
*Anja Heiduk, Dipl. Biol. {{hide|
[[Image:Molrec placeholder.png|130px|right]]
[[Image:Molrec placeholder.png|112px|right]]
  Tel.: +49 30 450 524 285
  Tel.: +49 30 450 xxx xxx
  Fax: +49 30 450 524 942
  Fax: +49 30 450 524 942
  E-Mail: zerrin.fidan(at)charite.de
  E-Mail: x(at)charite.de
}}
}}
*Annette Hayungs  - Secretary {{hide|
*Simone Jagdhuber, Studentin {{hide|
[[Image:Molrec placeholder.png|130px|right]]
[[Image:Molrec placeholder.png|112px|right]]
  Tel.: +49 30 450 524 092
  Tel.: +49 30 450 xxx xxx
  Fax: +49 30 450 524 942
  Fax: +49 30 450 524 942
  E-Mail: annette.hayungs(at)charite.de
  E-Mail: x(at)charite.de
}}
}}
*Marc Hovestädt - Doktorand {{hide|
*Ines Kretzschmar, TA {{hide|
[[Image:Molrec placeholder.png|130px|right]]
[[Image:Molrec placeholder.png|112px|right]]
  Tel.: +49 30 450 524 254
  Tel.: +49 30 x
  Fax: +49 30 450 524 942
  Fax: +49 30 x
  E-Mail: marc.hovestaedt(at)charite.de
  E-Mail: x(at)charite.de
}}
}}
*Ines Kretzschmar - CTA {{hide|
*Christiane Landgraf, TA {{hide|
[[Image:Molrec placeholder.png|130px|right]]
[[Image:Molrec placeholder.png|112px|right]]
Tel.: +49 30 450 524 253
  Tel.: +49 30 450 524 xxx
Fax: +49 30 450 524 942
E-Mail: ines.kretzschmar(at)charite.de
}}
*Christiane Landgraf - CTA {{hide|
[[Image:Molrec placeholder.png|130px|right]]
  Tel.: +49 30 450 524 253
  Fax: +49 30 450 524 942
  Fax: +49 30 450 524 942
  E-Mail: chl(at)charite.de
  E-Mail: chl(at)charite.de
}}
}}
*[http://openwetware.org/wiki/User:Carsten_C._Mahrenholz Carsten Mahrenholz] - Doktorand {{hide|
*Eric Moinet, Student {{hide|
[[Image:Molrec placeholder.png|130px|right]]
[[Image:Molrec placeholder.png|112px|right]]
  Tel.: +49 30 450 524 278
  Tel.: +49 30 450 524 xxx
  Fax: +49 30 450 524 942
  Fax: +49 30 450 524 942
  E-Mail: carsten.mahrenholz(at)charite.de
  E-Mail: x(at)charite.de
}}
*Judith Müller - Doktorandin {{hide|
[[Image:Molrec placeholder.png|130px|right]]
Tel.: +49 30 450 524 046
Fax: +49 30 450 524 942
E-Mail: judith.mueller(at)charite.de
}}
*Livia Otte - Postdoc {{hide|
[[Image:Molrec placeholder.png|130px|right]]
Tel.: +49 30 450 524 146
Fax: +49 30 450 524 942
E-Mail: livia.otte(at)charite.de
}}
*Rolf-Dietrich Stigler - IT- u. Sicherheitsbeauftragter {{hide|
[[Image:Molrec placeholder.png|130px|right]]
Tel.: +49 30 450 524 268
Fax: +49 30 450 524 942
E-Mail: rolf.stigler(at)charite.de
}}
}}
*[http://openwetware.org/wiki/User:Victor_Tapia Víctor Tapia] - Doktorand {{hide|
*[http://openwetware.org/wiki/User:Victor_Tapia Víctor Tapia] - Doktorand {{hide|
[[Image:Molrec placeholder.png|130px|right]]
[[Image:Molrec placeholder.png|112px|right]]
   Tel.: +49 30 450 524 046
   Tel.: +49 30 450 524 285
  Fax: +49 30 450 524 942
  Fax: +49 30 450 524 942
  E-Mail: victor.tapia(at)charite.de
  E-Mail: victor.tapia(at)charite.de; ve.tapia.m(at)gmail.com
}}
*Lars Vouillème - Doktorand {{hide|
[[Image:Molrec placeholder.png|130px|right]]
Tel.: +49 30 450 524 254
Fax: +49 30 450 524 942
E-Mail: lars.vouilleme(at)charite.de
}}
}}
<br>
<br>
</div><br>
</div><br>


==Research interest==  
==Research interest==
 
The AG Volkmer emerges from a strong training in peptide chemistry and cultivates its expertise in the synthesis and preparation of peptide/peptoide probes, either as core service or to meet the demands of our own research in cellular biology and molecular medicine.
The objectives of our research principally spread around three main topics: profiling the binding specificity of protein recognition modules, analyzing the diagnostic potential peptide-based analyte capture assays, and exploring the potential of peptide/peptoide probes to define or modulate specific therapeutic strategies.
<br>
===Profiling the binding specificity of protein recognition modules===
[[Image:Drawing.png|400px]]
<div style="padding: 10px; color: #000; background-color: #CEF2E0; width: 600px">
Protein recognition modules (PRM) are non-catalytic domains of protein structure dedicated to read molecular motifs of primary structure and post-translational modifications of proteins. Reading or recognition is not restricted to protein motifs, as shown by the emerging field of epigenetics. It is clear that methylation and other signatures on DNA are also recognized by modular structures of nuclear factors.
The tinkering of evolution has repeatedly duplicated and diverged different structural modules resulting in several homology families with some degree of functional conservation. This is observed as regular expressions of short linear motifs that can be recognized by a PRM family and by specific affinity traits of individual PRMs.
We aim to identify key events in cellular processes of information reading and transduction. Success in such aim translates to engineering congruent interaction networks, complementing drug efficiency and designing new therapeutic strategies, as has been shown by our group with several domains, i.e. WW domains in X-linked intellectual disorders and mechanosensing, SH3 domains in endocytosis, as well as PDZ domains in cystic fibrosis.
</div>
<br>
===Analyzing the diagnostic potential of peptide-based analyte capture assays===
<div style="padding: 10px; color: #000; background-color: #CEF2E0; width: 600px">
We intend to focus away from single biomarker for diagnosis and use either validated collections or agnostic collections of peptide probes to analyze complex biological samples. The former approach relies on the use of peptide probes known to interact with one or multiple target biomarkers for a specific pathology, the later one relies on extensive stochastic peptide probes to capture eventually unknown analytes in the sample that can be used as a diagnostic pattern of detection signals upon a multiplex binding assay.
The development of these approaches can be estimated from reports of our group and cooperation partners inside as well as outside RCIS. These reports show the difficulties and potential of the use of peptide probes to analyze blood samples and diagnose hypersensitivity, autoimmune responses, and immunological responses to infection.
</div>
<br>
===Exploring the therapeutic potential of peptide/peptoid probes===
<div style="padding: 10px; color: #000; background-color: #CEF2E0; width: 600px">
The flag ship of this research venue derives from the unique expertise for generating immobilized but C-terminal exposed peptide probes and accurate experience with PDZ specificity profiles. A peptide probe has been design to selectively inhibit the CFTR–CAL interaction —relevant in cystic fibrosis— without affecting the biologically relevant PDZ competitors NHERF1 and NHERF2.
In this venue of research we also explore the potential of cell penetrating peptides to be applied as vector to transport drug probes, such as the CFTR-CAL inhibitor, across the cell membrane.
</div>
<br>
===Technological Development of the Peptide Array Technologies===
===Technological Development of the Peptide Array Technologies===
by ''Victor Tapia'' <br>
by ''Victor Tapia'' <br>
FIGURE  {{hide|
<br>
----
----
A_[[image:Macro_to_microarrays_of_peptides.png|400px]] B_[[image:Fmoc-spotting.png|400px]]
[[image:Macro_to_microarrays_of_peptides.png|400px]]


'''PEPTIDE ARRAYS  ''' The combination of SPOT peptide synthesis (figure A, steps 1 to 4) with <br>
The combination of SPOT peptide synthesis (figure A, steps 1 to 4) with  
appropriate immobilization techniques on glass supports (figure A, steps <br>
appropriate immobilization techniques on glass supports (figure A, steps  
5 and 6) is wide spread. The SPOT technology provides low-scale but <br>
5 and 6) is wide spread. The SPOT technology provides low-scale but  
high-throughput synthesis, while immobilization of pre-synthesized<br>
high-throughput synthesis, while immobilization of pre-synthesized
peptides offers the benefit of a "chemical" purification step and <br>
peptides offers the benefit of a "chemical" purification step and  
flexible array design. Additionally, the glass support is compatible <br>
flexible array design. Additionally, the glass support is compatible  
with fluorescence detection (see figure B, adapted from the web) and <br>
with fluorescence detection and  
offers the possibility to miniaturize binding assays. Beyond economy, <br>
offers the possibility to miniaturize binding assays. Beyond economy,  
the later point is essential for quantitative measurements at the <br>
the later point is essential for quantitative measurements at the
steady-state of binding activity, as has been described [Ekins 1998] and <br>
steady-state of binding activity, as has been described [Ekins 1998] and  
can be proven by the mass-action law. <br>
can be proven by the mass-action law. <br>
----
----
<br>
<br>
}}
<div style="padding: 10px; color: #000; background-color: #CEF2E0; width: 600px">
<div style="padding: 10px; color: #ffffff; background-color: #000; width: 600px">
The basic point of this technology is the simultaneous display of a <br>
The basic point of this technology is the simultaneous display of a <br>
systematic collection of peptides on a planar support, on which numerous <br>
systematic collection of peptides on a planar support, on which numerous <br>
bimolecular interaction assays can be carried out under homogeneous <br>
bimolecular interaction assays can be carried out under homogeneous <br>
conditions. <br>
conditions. <br>
MORE  {{hide|
<br>
----
----
PEPTIDE ARRAYS IN THE ADVANCEMENT OF PEPTIDE SYNTHESIS<br>
PEPTIDE ARRAYS IN THE ADVANCEMENT OF PEPTIDE SYNTHESIS<br>
Line 185: Line 161:
under development [Goede, et al., 2005]. <br>
under development [Goede, et al., 2005]. <br>
<br>
<br>
----
PEPTIDE ARRAYS IN THE ADVANCEMENT OF BINDING ASSAY SYSTEMS <br>
PEPTIDE ARRAYS IN THE ADVANCEMENT OF BINDING ASSAY SYSTEMS <br>
<br>
<br>
Line 201: Line 178:
*  to 2000-4000 peptides in 1.5 cm2, in the case of microarrays generated by digital photolithography [El Khoury, et al., 2007; Gao, et al., 2004; Pellois, et al., 2000; Pellois, et al., 2002].   
*  to 2000-4000 peptides in 1.5 cm2, in the case of microarrays generated by digital photolithography [El Khoury, et al., 2007; Gao, et al., 2004; Pellois, et al., 2000; Pellois, et al., 2002].   
<br>
<br>
SUPPORT MATERIALS <br>
<br>
In order to
support synthesis, planar materials have to fulfil several requirements  <br>
including stability towards solvent and reagent deposition. The  <br>
functional groups on the surface must also be biochemically accessible  <br>
for chemical derivatisation. Furthermore, upon solid-phase binding  <br>
assay, generated peptides must be functionally displayed to allow  <br>
molecular recognition with a binding partner in the solution phase. In  <br>
particular non-specific interactions should be ruled out.
*  Flexible  porous supports such as cellulose [Eichler, et al., 1989; Frank and Döring, 1988], cotton [Eichler, et al., 1991; Schmidt and Eichler, 1993] or membranes [Daniels, et al., 1989; Wang and Laursen, 1992; Wenschuh, et al., 2000] are preferentially used for peptide array generation.  <br>
*  Rigid, non-porous materials such as glass [Falsey, et al., 2001], gold films [Houseman and Mrksich, 2002; Jonsson, et al., 1991; Malmqvist, 1993], or silicon [Fodor, et al., 1991; Pellois, et al., 2002] have also been used for in situ synthesis, but are much more technically demanding.  <br>
*  On the other side, rigid materials have a number of advantages over porous supports for functional display of molecules. Impermeability and smooth two-dimensionality of the material does not limit diffusion of the binding partner and leads to more accurate kinetics of recognition events. <br>
*  Finally the flatness and transparency of glass improve image acquisition and simplifies the use of fluorescence dyes for the read out process.  <br>
In some cases, assembled 3D structure on a non-porous surface could be  <br>
a fruitful approach. Several techniques for coherent surface modifications  <br>
are described over the past twenty years in the literature. For a comparative  <br>
overview on this field we refer to articles dedicated to the peptide and protein array  <br>
technologies [Angenendt and Glokler, 2004; Angenendt, et al., 2002;  <br>
Angenendt, et al., 2003; Seurynck-Servoss, et al., 2008;  <br>
Seurynck-Servoss, et al., 2007; Seurynck-Servoss, et al., 2007; Sobek,  <br>
et al., 2007; Sobek, et al., 2006; Wenschuh, et al., 2000].  <br>
}}
REFERENCES  {{hide|
----
----
* Angenendt, P., and Glokler, J. (2004) Evaluation of antibodies and microarray coatings as a prerequisite for the generation of optimized antibody microarrays, Methods Mol Biol 264, 123-34.
SOURCES: For references to citations above see
* Angenendt, P., Glokler, J., Murphy, D., Lehrach, H., and Cahill, D. J. (2002) Toward optimized antibody microarrays: a comparison of current microarray support materials, Anal Biochem 309, 253-60.
* Tapia, V.E., Ay, B., Volkmer, R., 2009. Exploring and Profiling Protein Function with Peptide Arrays, in: Marina Cretich, Chiari, M. (Eds.), Peptide Microarrays. Humana Press, Totowa, NJ, pp. 3–17.
* Angenendt, P., Glokler, J., Sobek, J., Lehrach, H., and Cahill, D. J. (2003) Next generation of protein microarray support materials: evaluation for protein and antibody microarray applications, J Chromatogr A 1009, 97-104.
* Tapia, VE & R Volkmer, 2009. Steady State Analysis of Peptide Array-based Binding Assays [https://www.openwetware.org/images/e/e7/Steady-state_binding_asssays.pdf]
* Daniels, S. B., Bernatowicz, M. S., Coull, J. M., and Köster, H. (1989) Membranes as solid supports for peptide synthesis., Tetrahedron Lett. 30.
* Eichler, J., Beyermann, M., and Bienert, M. (1989) Application of cellulose paper as support in simultaneous solid phase peptide synthesis., Colect. Czech. Chem. Commun. 54, 1746-52.
* Eichler, J., Bienert, M., Stierandova, A., and Lebl, M. (1991) Evaluation of cotton as a carrier for solid-phase peptide synthesis., Peptide Res. 4, 296-307.
* Ekins, R., Chu, F., and Biggart, E. (1990) Multispot, multianalyte, immunoassay, Ann Biol Clin (Paris) 48, 655-66.
* Ekins, R. P. (1989) Multi-analyte immunoassay, J Pharm Biomed Anal 7, 155-68.
* Ekins, R. P. (1998) Ligand assays: from electrophoresis to miniaturized microarrays, Clin Chem 44, 2015-30.
* El Khoury, G., Laurenceau, E., Dugas, V., Chevolot, Y., Merieux, Y., Duclos, M. C., Souteyrand, E., Rigal, D., Wallach, J., and Cloarec, J. P. (2007) Acid deprotection of covalently immobilized peptide probes on glass slides for peptide microarrays, Conf Proc IEEE Eng Med Biol Soc 2007, 2242-6.
* Falsey, J. R., Renil, M., Park, S., Li, S., and Lam, K. S. (2001) Peptide and small molecule microarray for high throughput cell adhesion and functional assays, Bioconjug Chem 12, 346-53.
* Fields, G. B., and Noble, R. L. (1990) Solid phase peptide synthesis utilizing 9-fluorenylmethoxycarbonyl amino acids, Int J Pept Protein Res 35, 161-214.
* Fodor, S. P., Read, J. L., Pirrung, M. C., Stryer, L., Lu, A. T., and Solas, D. (1991) Light-directed, spatially addressable parallel chemical synthesis, Science 251, 767-73.
* Frank, R. (1992) Spot-synthesis: an easy technique for the positionally addressable, parallel chemical synthesis on a membrane support, Tetrahedron, 9217-32.
* Frank, R. (2002) The SPOT-synthesis technique: Synthetic peptide arrays on membrane supports--principles and applications, J. Immunol. Methods 267, 13-26.
* Frank, R., and Döring, R. (1988) Simultaneous multiple peptide synthesis under continuous flow conditions on cellulose paper disks as segmental solid supports, Tetrahedron 44, 6031-40.
* Gao, X., Pellois, J. P., Na, Y., Kim, Y., Gulari, E., and Zhou, X. (2004) High density peptide microarrays. In situ synthesis and applications, Mol Divers 8, 177-87.
*Geysen, H. M., Meloen, R. H., and Barteling, S. J. (1984) Use of peptide synthesis to probe viral antigens for epitopes to a resolution of a single amino acid, Proc Natl Acad Sci U S A 81, 3998-4002.
*Goede, A., Jaeger, I. S., and Preissner, R. (2005) SUPERFICIAL--surface mapping of proteins via structure-based peptide library design, BMC Bioinformatics 6, 223.
*Gutte, B., and Merrifield, R. B. (1969) The total synthesis of an enzyme with ribonuclease A activity, J Am Chem Soc 91, 501-2.
*Houseman, B. T., and Mrksich, M. (2002) Towards quantitative assays with peptide chips: a surface engineering approach, Trends Biotechnol 20, 279-81.
*Jonsson, U., Fagerstam, L., Ivarsson, B., Johnsson, B., Karlsson, R., Lundh, K., Lofas, S., Persson, B., Roos, H., Ronnberg, I., and et al. (1991) Real-time biospecific interaction analysis using surface plasmon resonance and a sensor chip technology, Biotechniques 11, 620-7.
*Joos, T. O., Stoll, D., and Templin, M. F. (2002) Miniaturised multiplexed immunoassays, Curr Opin Chem Biol 6, 76-80.
*Malmqvist, M. (1993) Biospecific interaction analysis using biosensor technology, Nature 361, 186-7.
*Merrifield, R. B. (1965) Automated synthesis of peptides, Science 150, 178-85.
*Pellois, J. P., Wang, W., and Gao, X. (2000) Peptide synthesis based on t-Boc chemistry and solution photogenerated acids, J Comb Chem 2, 355-60.
*Pellois, J. P., Zhou, X., Srivannavit, O., Zhou, T., Gulari, E., and Gao, X. (2002) Individually addressable parallel peptide synthesis on microchips, Nat Biotechnol 20, 922-6.
*Reimer, U., Reineke, U., and Schneider-Mergener, J. (2002) Peptide arrays: from macro to micro, Curr Opin Biotechnol 13, 315-20.
*Schmidt, M., and Eichler, J. (1993) Multiple peptide synthesis using cellulose-based carriers: Synthesis of substance P - diastereoisomers and their histamine-releasing activity., Bioorg. Med. Chem. Lett. 3, 441-46.
*Schutkowski, M., Reimer, U., Panse, S., Dong, L., Lizcano, J. M., Alessi, D. R., and Schneider-Mergener, J. (2004) High-content peptide microarrays for deciphering kinase specificity and biology, Angew Chem Int Ed Engl 43, 2671-4.
*Seurynck-Servoss, S. L., Baird, C. L., Miller, K. D., Pefaur, N. B., Gonzalez, R. M., Apiyo, D. O., Engelmann, H. E., Srivastava, S., Kagan, J., Rodland, K. D., and Zangar, R. C. (2008) Immobilization strategies for single-chain antibody microarrays, Proteomics 8, 2199-210.
*Seurynck-Servoss, S. L., Baird, C. L., Rodland, K. D., and Zangar, R. C. (2007) Surface chemistries for antibody microarrays, Front Biosci 12, 3956-64.
*Seurynck-Servoss, S. L., White, A. M., Baird, C. L., Rodland, K. D., and Zangar, R. C. (2007) Evaluation of surface chemistries for antibody microarrays, Anal Biochem 371, 105-15.
*Sobek, J., Aquino, C., and Schlapbach, R. (2007) Quality considerations and selection of surface chemistry for glass-based DNA, peptide, antibody, carbohydrate, and small molecule microarrays, Methods Mol Biol 382, 17-31.
*Sobek, J., Bartscherer, K., Jacob, A., Hoheisel, J. D., and Angenendt, P. (2006) Microarray technology as a universal tool for high-throughput analysis of biological systems, Comb Chem High Throughput Screen 9, 365-80.
*Templin, M. F., Stoll, D., Schrenk, M., Traub, P. C., Vohringer, C. F., and Joos, T. O. (2002) Protein microarray technology, Drug Discov Today 7, 815-22.
*Wang, Z., and Laursen, R. A. (1992) Multiple peptide synthesis on polypropylene membranes for rapid screening of bioactive peptides., Pep. Res. 5, 275-80.
*Wenschuh, H., Volkmer-Engert, R., Schmidt, M., Schulz, M., Schneider-Mergener, J., and Reineke, U. (2000) Coherent membrane supports for parallel microsynthesis and screening of bioactive peptides, Biopolymers 55, 188-206.


}}
</div>
</div>
<br>
<br>
===Structural Modularity  in Protein-Protein Recognition===
by ''Victor Tapia'' <br>
FIGURE  {{hide|
----
[[image:placeholder.png|400px]]
text
----
}}
====Protein Interaction Domains====
<div style="padding: 10px; color: #ffffff; background-color: #000; width: 600px">
The organisation of living systems is a complex network of molecular <br>
interactions. Proteins are a central component of the network as they <br>
may bind to other proteins as well as to phospholipids, nucleic acids <br>
and small molecules to interconnect the diverse physiological functions <br>
of the cell. In the background of these observations, the existence of a <br>
molecular recognition code for cellular organisation is very suggestive. <br>
'''MORE TEXT''' {{hide|
----
Structural analysis of functional protein complexes suggests at least <br>
two classes of protein-protein interaction that may be extendable to the <br>
other kinds of protein interactions. In the first class, the <br>
complementary surfaces of the interacting partners are both extensive. <br>
Under these circumstances, the residues involved in each interacting <br>
surface come together only upon protein folding. The second class <br>
consists on asymmetric interactions, where a protein domain (folding <br>
motive of moderate size like a pocket on the protein’s surface) may dock <br>
a short lineal peptide motive (a peptide ligand) on the partner protein. <br>
While interactions over extensive surfaces cannot be inferred, the <br>
binding determinants of a protein interaction domain (PID) may be mapped <br>
to short peptides matching the sequence of the ligand peptide. The <br>
importance of small recognition domains in the formation of protein <br>
complexes by binding to short lineal peptides was demonstrated in the <br>
late 1980s and early 1990s (Sadowski, I. et al., 1986; Ren, R. et al., <br>
1993; Mayer, B.J. et al., 1993).<br>
<br>
In this era of extensive genome sequencing, many PIDs have been <br>
discovered. The interaction partners and, therefore, the functions of <br>
such proteins may be determined by identifying the critical binding sites for <br>
one family member through evolutionary tracing (Lichtarge, O. et al., 1996) or <br>
through high-parallel screening of functional protein arrays (Phizicky, <br>
E. et al, 2003). Many of the PIDs in proteins can be grouped into <br>
families that show clear evidence of their evolution from a common <br>
ancestor, and genome sequences from Saccharomyces cerevisiae to Homo <br>
sapiens reveal large numbers of proteins that contain one or more common <br>
domains. <br>
}}
</div>
<br>
====Src Homology Families - A PID Prototype====
<div style="padding: 10px; color: #ffffff; background-color: #000; width: 600px">
In a pioneering work on the kinase function and transforming activity of <br>
the Fujinami Sarcoma Virus, Sadowski et al. (1986) discovered “a unique <br>
domain… (which) is absent from kinases that span the plasma membrane” <br>
and concluded that “the presence of this noncatalytic domain in all <br>
known cytoplasmic tyrosine kinases of higher and lower eucaryotes argues <br>
for an important biological function... the noncatalytic domain may <br>
direct specific interactions of the enzymatic region with cellular <br>
components that regulate or mediate tyrosine kinase function”. These <br>
regions were called Src homology 2 (SH2) and 3 (SH3), the name SH1 being <br>
reserved to the catalytic region. Since then, the gained knowledge on SH <br>
domain function has been a paradigm in our understanding of PID <br>
biochemistry. <br>
'''MORE TEXT''' {{hide|
----
The structure of SH2 family members involves about 100 residues that, in <br>
the case of the kinase Src, are located N terminal to the catalytic <br>
region and resembles a pocket dominated by a ß-sheet sandwiched between <br>
a pair of a-helices. SH2 domains bind the protein containing them to a <br>
second protein on a phosphorylated tyrosine residue (pY) in a specific <br>
amino acid sequence context (Ladbury, J.E. et al., 2000).<br>
<br>
The SH3 domain structure, also found in cytoplasmic kinases like Src, <br>
consists largely of two ? sheets that form a partly open ß-barrel. The <br>
ligand-binding site is a hydrophobic surface showing three shallow <br>
pockets or grooves defined by conserved aromatic residues. The ligand <br>
adopts an extended, left-handed helical conformation termed the <br>
polyproline-2 (or PPII) helix. Two of the binding pockets of the SH3 <br>
domain are occupied by two hydrophobic proline dipeptides on two <br>
adjacent turns of the helix, whereas the third ‘specificity’ pocket in <br>
most cases interacts with a basic residue in the ligand distal to the <br>
xPxxP core conserved motive of the PPII helix (Mayer, B.J. et al., <br>
2001).<br> <br> The amino acids located at the binding site for the <br>
phosphorylated polypeptide of SH2 and for the polyprolin core of SH3 <br>
have been the slowest to change during the long evolutionary process <br>
that produced the large SH2 and SH3 families of peptide recognition <br>
domains. Because mutation is a random process, this result is attributed <br>
to the preferential elimination during evolution of all organisms whose <br>
SH domains became altered in a way that inactivated the SH-binding site, <br>
thereby destroying the function of the SH domain. Are the PID/ligand <br>
interactions specific enough or must a certain interaction compete with <br>
the bulk of structurally similar structures in a struggle for dynamical <br>
complex formation? <br>
}}
</div>
<br>
====From Promiscuous Recognition Events to Mutually Exclusive Cellular Responses====
UPCOMMING: list of cited authors
<div style="padding: 10px; color: #ffffff; background-color: #000; width: 600px">
The elucidation of functional pathways of signal transduction, <br>
biochemical function or gene regulation, is firstly addressed in <br>
proteomics by deriving interaction networks depicting ideally all <br>
interactions in the cell. Several attempts have been done in this <br>
direction on different model organisms and with varied methods, <br>
including co-purification by affinity chromatography (Ho, Y. et al., <br>
2002; Gavin, A.-C. et al., 2002; Bouwmeester, T. et al., 2004), yeast <br>
two-hybrid, phage display, peptide array technologies, etc. A comparison <br>
of datasets derived by individual methods demonstrates that <br>
different methods have different potential. For example, affinity <br>
chromatographic approaches are biased to tight interactions such as <br>
those involving extensive complementary surfaces, while <br>
interactions in which one of the two partners contains at least one <br>
PID are more frequent in the two-hybrid database. The higher <br>
sensitivity of the so called synthetic approaches (yeast <br>
two-hybrid, phage display and peptide array technologies) make them <br>
better suited for detecting PID-mediated interactions since their <br>
peptide affinity in terms of Kd falls in the 10 – 100 µM range (high Kd <br>
--> low affinity). However, this advantage is counterbalanced by a low <br>
specificity, especially of the yeast two-hybrid approach (Phizyki, 2002). <br>
'''MORE TEXT''' {{hide|
----
In order to correct this deficiency a double check-up of the information <br>
fed into the interaction databases is recommended. This can be achieved <br>
by deriving two interaction networks through orthogonal (fundamentally <br>
different) synthetic methods and then considering only the intersection <br>
between the two datasets (Tong, A.H.Y. et al.,2002; Castagnoli, L. et <br>
al., 2004; Landgraf, C. et al., 2004). False positive reports are thus <br>
reduced if the causes for measurement error are different in each <br>
method.<br> <br> The strength of this combined approach to deliver <br>
physiologically relevant interactions has been proven for a phage <br>
display/yeast two-hybrid intersected dataset (Tong, A.H.Y. et al.,2002). <br>
A notable conclusion of this approach is that the intersected dataset of <br>
proteins that are able to interact with a given PID is larger than <br>
expected when cellular events are viewed as a precise wiring of the <br>
proteins in the cell. Although a set of these biochemically potential <br>
binders may have no physiological relevance due to expression at <br>
different times or tissues, in vitro disrupted structures, etc., the <br>
paradox of promiscuous recognition and mutually exclusive responses <br>
seems to be inherent to PID mediated interactions: the recent work of <br>
Landgraf et al. (2004) supports the observation that a large fraction of <br>
natural peptides with the biochemical potential to bind to any given SH3 <br>
domain is actually used in vivo to mediate the formation of a <br>
complex.<br> <br> An additional difficulty to derive functional <br>
interaction pathways is that the difference in affinity between <br>
‘specific’ and ‘non-specific’ interactions has been shown to be less <br>
than two orders of magnitude in the case of SH2 and its peptide ligands <br>
(Songyang, Z. et al., 2004). Even when granted that the recognition <br>
specificity of intact proteins by SH3 domains is greater than for <br>
SH3-peptide recognition, affinity is not raised above one order of <br>
magnitude (Arold, S. et al., 1998; Lee, C.H. et al., 1995). Moreover, <br>
the ability of a point-mutant Src SH2 domain to effectively substitute <br>
for the SH2 domain of the Sem-5 protein in activation of the Ras pathway <br>
in vivo emphasises that the specificity of Sh2-mediated interactions is <br>
not great (Marengere, L.E. et al., 1994). Consider the later statements <br>
under the light of the fact that the affinity of the protein OppA for <br>
its ligands is in the range of two orders of magnitude (Oppa is involved <br>
in the mopping of peptides in the bacterial periplasm exhibiting no <br>
sequence specificity). Tu put it all into a nutshell: the described <br>
facts lead to a view of large and promiscuous SH-mediated interaction <br>
networks.<br> <br> Since it is possible to generate mutant SH3 domains <br>
that have up to 40-fold higher affinity than their wild-types (Hiipakka <br>
et al, 1999) , the potential of these domains as research tools and as <br>
source of lead compounds for pharmaceutical development can not be <br>
overseen. Furthermore, a question cannot be overheard in our minds: <br>
which is the functional advantage of maintaining relative low affinity <br>
and selectivity for PID-mediated interactions, instead of optimizing the <br>
potential affinity of PIDs? And further: how can PID-dependent <br>
interaction pathways achieve precise cellular responses?<br>
<br>
A comfortable view is that sufficient effective selectivity can be brought <br>
by compartmentalization, additive effects of multiple separate <br>
interactions, cooperative assembly of multiprotein complexes, etc. and <br>
that this effects can sustain linear functional pathways. An interesting <br>
insight into this mater has been advanced by Zarrinpar, A. et al. In <br>
their work (2003) the authors find out that while metazoan SH3 domains <br>
may rescue the functionality of mutated Sho1-SH3 of the yeast, in the <br>
set of yeast-own SH3 domains this promiscuity is forbidden. They thus <br>
conclude and confirm that, on the background of diverging SH3 domains, <br>
negative selection has drifted the ligand sequences to non-overlapping <br>
areas of the particular SH3 binding regions on the sequence space. <br>
Alternatively, a divergence process of the shape of the binding region <br>
may be ‘guided’ by positive selection to avoid overlapping and, thus, <br>
promiscuitive interactions. Nevertheless, the picture of linear functional <br>
pathways is being revolutionized by a more probabilistic view of a dynamical <br>
equilibrium between multiple interactions, in which “the central organizing <br>
principle is a vast and ever-shifting web of interactions, from which output <br>
is gauged by global changes in complex binding equilibria” (Mayer, B. J., 2001). <br>
}}
</div><br>


== Who's visiting ==
== Who's visiting ==
<div style="padding: 10px; color: #ffffff; background-color: #000; width: 600px">
<div style="padding: 10px; color: #000; background-color: #CEF2E0; width: 600px">
start on 18 Mar 2010
start on 18 Mar 2010


Latest revision as of 06:11, 13 November 2014


Contact Information

Molecular Recognition Laboratorium,
Institute für medizinische Immunologie
CHARITÉ - UNIVERSITÄTSMEDIZIN BERLIN

	Hessische Str. 3-4
	D-10115 Berlin, Germany
	
	phone  +49-30-450 524092 
	fax    +49-30-450 524942 
	mail   annette.hayungs@charite.de
 	web    charite.de

last change on 01.04.2010


Group Leader

Rudolf Volkmer 

	Tel.:	+49 30 450 524 267
	Fax:	+49 30 450 524 942
	E-Mail:	rve(at)charite.de



Group Members

  • Magdalena Czuban, Dipl. Biol. 
	Tel.:	+49 30 450 xxx xxx
	Fax:	+49 30 450 524 942
	E-Mail:	x(at)charite.de
  • Mercedes Gonzáles, Studentin 
	Tel.:	+49 30 450 xxx xxx
	Fax:	+49 30 450 524 942
	E-Mail:	x(at)charite.de
  • Anja Heiduk, Dipl. Biol. 
	Tel.:	+49 30 450 xxx xxx
	Fax:	+49 30 450 524 942
	E-Mail:	x(at)charite.de
  • Simone Jagdhuber, Studentin 
	Tel.:	+49 30 450 xxx xxx
	Fax:	+49 30 450 524 942
	E-Mail:	x(at)charite.de
  • Ines Kretzschmar, TA 
	Tel.:	+49 30 x
	Fax:	+49 30 x
	E-Mail:	x(at)charite.de
  • Christiane Landgraf, TA 
	Tel.:	+49 30 450 524 xxx
	Fax:	+49 30 450 524 942
	E-Mail:	chl(at)charite.de
  • Eric Moinet, Student 
	Tel.:	+49 30 450 524 xxx
	Fax:	+49 30 450 524 942
	E-Mail:	x(at)charite.de
	 	

 	Tel.:	+49 30 450 524 285
	Fax:	+49 30 450 524 942
	E-Mail:	victor.tapia(at)charite.de; ve.tapia.m(at)gmail.com



Research interest

The AG Volkmer emerges from a strong training in peptide chemistry and cultivates its expertise in the synthesis and preparation of peptide/peptoide probes, either as core service or to meet the demands of our own research in cellular biology and molecular medicine. The objectives of our research principally spread around three main topics: profiling the binding specificity of protein recognition modules, analyzing the diagnostic potential peptide-based analyte capture assays, and exploring the potential of peptide/peptoide probes to define or modulate specific therapeutic strategies.

Profiling the binding specificity of protein recognition modules

Protein recognition modules (PRM) are non-catalytic domains of protein structure dedicated to read molecular motifs of primary structure and post-translational modifications of proteins. Reading or recognition is not restricted to protein motifs, as shown by the emerging field of epigenetics. It is clear that methylation and other signatures on DNA are also recognized by modular structures of nuclear factors. The tinkering of evolution has repeatedly duplicated and diverged different structural modules resulting in several homology families with some degree of functional conservation. This is observed as regular expressions of short linear motifs that can be recognized by a PRM family and by specific affinity traits of individual PRMs. We aim to identify key events in cellular processes of information reading and transduction. Success in such aim translates to engineering congruent interaction networks, complementing drug efficiency and designing new therapeutic strategies, as has been shown by our group with several domains, i.e. WW domains in X-linked intellectual disorders and mechanosensing, SH3 domains in endocytosis, as well as PDZ domains in cystic fibrosis.


Analyzing the diagnostic potential of peptide-based analyte capture assays

We intend to focus away from single biomarker for diagnosis and use either validated collections or agnostic collections of peptide probes to analyze complex biological samples. The former approach relies on the use of peptide probes known to interact with one or multiple target biomarkers for a specific pathology, the later one relies on extensive stochastic peptide probes to capture eventually unknown analytes in the sample that can be used as a diagnostic pattern of detection signals upon a multiplex binding assay. The development of these approaches can be estimated from reports of our group and cooperation partners inside as well as outside RCIS. These reports show the difficulties and potential of the use of peptide probes to analyze blood samples and diagnose hypersensitivity, autoimmune responses, and immunological responses to infection.


Exploring the therapeutic potential of peptide/peptoid probes

The flag ship of this research venue derives from the unique expertise for generating immobilized but C-terminal exposed peptide probes and accurate experience with PDZ specificity profiles. A peptide probe has been design to selectively inhibit the CFTR–CAL interaction —relevant in cystic fibrosis— without affecting the biologically relevant PDZ competitors NHERF1 and NHERF2. In this venue of research we also explore the potential of cell penetrating peptides to be applied as vector to transport drug probes, such as the CFTR-CAL inhibitor, across the cell membrane.


Technological Development of the Peptide Array Technologies

by Victor Tapia

The combination of SPOT peptide synthesis (figure A, steps 1 to 4) with appropriate immobilization techniques on glass supports (figure A, steps 5 and 6) is wide spread. The SPOT technology provides low-scale but high-throughput synthesis, while immobilization of pre-synthesized peptides offers the benefit of a "chemical" purification step and flexible array design. Additionally, the glass support is compatible with fluorescence detection and offers the possibility to miniaturize binding assays. Beyond economy, the later point is essential for quantitative measurements at the steady-state of binding activity, as has been described [Ekins 1998] and can be proven by the mass-action law.


The basic point of this technology is the simultaneous display of a
systematic collection of peptides on a planar support, on which numerous
bimolecular interaction assays can be carried out under homogeneous
conditions.

PEPTIDE ARRAYS IN THE ADVANCEMENT OF PEPTIDE SYNTHESIS

  • The development of solid-phase peptide synthesis (SPPS) by Bruce Merrifield [Gutte and Merrifield, 1969; Merrifield, 1965] and adaptions of this procedure [Fields and Noble, 1990] set the chemical ground for innovative technologies to follow.
  • The development of the “Pin” method by H. Geysen [Geysen, et al., 1984] introduces the array format to peptide synthesis.
  • Definitive establishment of peptide arrays came along with the development of the SPOT synthesis by Roland Frank [Frank, 1992; Frank, 2002] which simplified chemical synthesis of peptide arrays to the addressable deposition of reagents on a cellulose sheet.


Modern peptide synthesis approaches and
molecular biology make peptides accessible in a high degree of
structural diversity. The two greatest drawbacks of synthetic peptide
arrays are peptide length, with a quality threshold between 30 and 50
amino-acids, as well as the restriction to linear motives, since the
mimicry of nonlinear motives with linear peptide constructs is still
under development [Goede, et al., 2005].

PEPTIDE ARRAYS IN THE ADVANCEMENT OF BINDING ASSAY SYSTEMS

Since the 90s a major aspect of development to achieve the required
sensitivities to analyse biological samples has been the miniaturization
of analytical devices [Ekins, 1998]. It is important to note that
miniaturization is not only a matter of high-throughput and economy.
Miniaturization is an essential factor that should provide saturation of
binding sites under low analyte concentrations without significantly
altering its bulk (or ambient) concentration upon capturing [Ekins, et
al., 1990; Ekins, 1989; Joos, et al., 2002; Templin, et al., 2002].

  • In this sense, the first application of a peptide microarray device in 1991, anticipating even the application of cDNA arrays, achieved already the impressive feature density of about 1024 peptides in 1.6 cm2 by means of in situ light-directed parallel synthesis [Fodor, et al., 1991].

Several methods available to generate peptide arrays on planar solid surfaces offer a range between...

  • 16 peptides per cm2, in the case of SPOT macroarrays [Reimer, et al., 2002; Schutkowski, et al., 2004],
  • to 2000-4000 peptides in 1.5 cm2, in the case of microarrays generated by digital photolithography [El Khoury, et al., 2007; Gao, et al., 2004; Pellois, et al., 2000; Pellois, et al., 2002].


SOURCES: For references to citations above see

  • Tapia, V.E., Ay, B., Volkmer, R., 2009. Exploring and Profiling Protein Function with Peptide Arrays, in: Marina Cretich, Chiari, M. (Eds.), Peptide Microarrays. Humana Press, Totowa, NJ, pp. 3–17.
  • Tapia, VE & R Volkmer, 2009. Steady State Analysis of Peptide Array-based Binding Assays [1]


Who's visiting

start on 18 Mar 2010

<html> <a href="http://www2.clustrmaps.com/counter/maps.php?url=http://openwetware.org/wiki/Molecular_Recognition_Laboratorium" id="clustrMapsLink"><img src="http://www2.clustrmaps.com/counter/index2.php?url=http://openwetware.org/wiki/Molecular_Recognition_Laboratorium" style="border:0px;" alt="Locations of visitors to this page" title="Locations of visitors to this page" id="clustrMapsImg" onerror="this.onerror=null; this.src='http://clustrmaps.com/images/clustrmaps-back-soon.jpg'; document.getElementById('clustrMapsLink').href='http://clustrmaps.com';" /> </a> </html>

Science in the city: A small series about the everyday life of scientists in berlin

FOLLOW ME >>>>

Retrieved from "https://openwetware.org/mediawiki/index.php?title=Molecular_Recognition_Laboratorium&oldid=843763"