Objective
- The objective for today is to perform a redox titration on HRP in order to determine the standard redox potential of the protein.
Redox Titration
- The protocol for this lab was found here.
Specific volume of samples used during redox titration.
Sample number
|
Volume of HRP Sample(mL)
|
1 |
1
|
2 |
1.05
|
3 |
1.055
|
4 |
1.056
|
5 |
1.059
|
6 |
1.064
|
7 |
1.074
|
8 |
1.084
|
Absorbance Spectra of the redox titration of HRP
- The maximum wavelength of fully oxidized HRP was 402.22nm, and the wavelength corresponding to the fully reduced HRP was 433.74nm. The sample with the addition of 64μL sodium dithionite was the fully oxidized sample, and the sample with the addition of 84uL sodium dithionite was the fully reduced sample. Since the reaction was not done in an entirely closed environment, oxygen from the atmosphere reacted with our sample which explains the large volumes added to our samples.
Potential of Redox titration of HRP
Redox Titration of HRP
% Oxidized
|
Potential
|
-2.633063185 |
-0.5122
|
0 |
-0.5803
|
3.260060544 |
-0.4781
|
30.97191805 |
-0.4045
|
82.70859316 |
0.0146
|
98.04493512 |
-0.3879
|
98.62977455 |
-0.355
|
100 |
-0.3519
|
Redox titration of HRP % reduced data
% Reduced
|
Potential
|
-2.73671656 |
0.0146
|
-0.472156173 |
-0.355
|
0 |
-0.3519
|
0.156439504 |
-0.3879
|
56.60826937 |
-0.4045
|
94.88970062 |
-0.4045
|
96.52628268 |
-0.4781
|
100 |
-0.5803
|
|