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THE REDUCING GROUPS OF PROTEINS
1Hospital of The Rockefeller Institute for Medical Research, New York, and the Laboratories of The Rockefeller Institute for Medical Research, Princeton, N. J.
The Journal of General Physiology
|October 30, 2009
Summary
Intact proteins have reducing groups beyond sulfhydryl (SH) groups that react with ferricyanide. Their activity is influenced by protein structure, pH, temperature, and the presence of SH groups.
Area of Science:
- Biochemistry
- Protein Chemistry
Background:
- Proteins contain sulfhydryl (SH) groups known for their reducing properties.
- The full extent of reducing functionalities in intact proteins remains incompletely understood.
Purpose of the Study:
- To identify and characterize non-SH reducing groups in intact proteins.
- To investigate the factors influencing the activity of these newly identified reducing groups.
Main Methods:
- Oxidation of intact, unhydrolyzed proteins using ferricyanide.
- Assessing the impact of denaturation, pH, temperature, and SH group presence on reducing activity.
Main Results:
- Intact proteins exhibit reducing groups in addition to SH groups, reactive with ferricyanide.
- The activity of these non-SH reducing groups is enhanced by denaturation, increased pH, and temperature.
- Their reactivity differs from SH groups concerning ferricyanide concentration and contact time.
- Presence of protein SH groups potentiates the activity of these other reducing groups.
- These groups are likely located within tyrosine and tryptophan residues.
Conclusions:
- Proteins possess multiple reducing functionalities beyond SH groups.
- These additional reducing groups play a role in protein denaturation and tissue redox properties.
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