Changes in conformation of reduced cytochrome c in neutral aqueous solution

Area of Science:

• Biochemistry
• Radiation Chemistry
• Protein Chemistry

Background:

• Cytochrome c is a vital protein in cellular respiration.
• Alcohols are known to interact with and alter protein structures.
• Radiation can induce chemical changes in biological molecules.

Purpose of the Study:

• To investigate the effect of high alcohol concentrations on cytochrome c structure.
• To understand the conformational changes of ferrocytochrome c upon radiation-induced reduction.
• To characterize the relaxation dynamics of altered cytochrome c conformers.

Main Methods:

• Exposure of cytochrome c in neutral aqueous solutions with high alcohol concentrations to ionizing radiation.
• Spectroscopic analysis to detect and characterize protein conformers.
• Kinetic studies to determine the rate of structural relaxation.

Main Results:

• High alcohol concentrations induce abnormal ferrocytochrome c conformers upon radiation reduction.
• These abnormal conformers are structurally similar to those observed under alkaline reduction conditions.
• The abnormal conformers relax to the native ferrocytochrome c structure within approximately 0.1 seconds.

Conclusions:

• Alcohol-induced perturbations in neutral solutions facilitate the formation of radiation-induced abnormal cytochrome c structures.
• The observed structural relaxation indicates a dynamic process in protein refolding.
• These findings highlight the sensitivity of cytochrome c conformation to its solution environment during redox transitions.