Interplay between oonformational changes and peroxidase activity of cytochrome c.

摘要

The latest function attributed to cyt c has been associated to its ability to be activated and fulfill the task of a peroxidase The hallmark of cyt c with peroxidase activity is the partial unfolding accompanied by loosening of the Fe sixth axial bond and enhanced access of the heme catalytic site to small molecules like H_2O_2. To investigate the peroxidase activity of cyt c as a function of its conformation, we generated different "non native" forms of cyt c (lipid-cyt c complex, reconstituted cyt c from two fragments or mutated cytochromes c). Such partially unfolded proteins were characterized by spectroscopic techniques. The steady-state kinetic of their peroxidase activities was studied and the inhibitory effect of minocycline on such activity has been investigated.