抄録
Optical properties of models for the ligation in cytochrome P-450 system were investigated by interaction of hemin with biologically significant thiol compounds such as cysteine and cysteine methyl ester, in the presence of such bases as pyridine, imidazol and histidine under physiological condition. It is shown that cysteine binds to ferric porphyrin to form axial S-Fe-N coordination in the presence of a base, and ferric porphyrin is easily reduced to ferrous porphyrin by an excess thiol. Under exposure of CO of these systems, the characteristic absorption band at 450 nm was observed, which is typical with cytochrome P-450·CO complex. These results would show that the model used nicely represent the reaction involved in the vicinity of heme moiety of cytochrome P-450 under physiological condition.
