TY - JOUR
T1 - Cytochrome P450-like substrate oxidation catalyzed by cytochrome c and immobilized cytochrome c
AU - Akasaka, Reiko
AU - Mashino, Tadahiko
AU - Hirobe, Masaaki
PY - 1993
Y1 - 1993
N2 - Cytochrome c (cyt.c) was shown to catalyze cytochrome P450 (P450)-like oxidative reactions, such as N-, and 0-demethylation, S-oxidation, and epoxidation of olefins. A more detailed examination showed that (i) N-methylcarbazole and thioanisole oxidation with H2 18O2 catalyzed by cyt.c resulted in introduction of 18O into the product, and (ii) during the epoxidation of cis-stilbene catalyzed by cyt.c, the stereochemistry of the substrate was retained and 18O was introduced when H2 18O2 was used as an oxidant. These results show that cyt.c catalyzed N-demethylation, S-oxidation, and epoxidation in the same manner as P450. To utilize these P450-like reactivities effectively, cyt.c was immobilized on poly-γ-methyl-L-glutamate. Up to 99% of the cyt.c used was immobilized. This immobilized cyt.c catalyzed N-demethylation, S-oxidation, and epoxidation in the same manner as both P450 and free cyt.c, and the activities of these reactions were increased by the immobilization. In N-demethylation of N, N-dimethylaniline with cumene hydroperoxide (CHP) catalyzed by cyt.c, the Vmax for CHP was increased by 4.4-fold by the immobilization of the enzyme, while the Km remained unchanged. Since P450 is involved in the metabolism of many xenobiotics, the above results suggest that immobilized cyt.c may be useful in drug metabolism research.
AB - Cytochrome c (cyt.c) was shown to catalyze cytochrome P450 (P450)-like oxidative reactions, such as N-, and 0-demethylation, S-oxidation, and epoxidation of olefins. A more detailed examination showed that (i) N-methylcarbazole and thioanisole oxidation with H2 18O2 catalyzed by cyt.c resulted in introduction of 18O into the product, and (ii) during the epoxidation of cis-stilbene catalyzed by cyt.c, the stereochemistry of the substrate was retained and 18O was introduced when H2 18O2 was used as an oxidant. These results show that cyt.c catalyzed N-demethylation, S-oxidation, and epoxidation in the same manner as P450. To utilize these P450-like reactivities effectively, cyt.c was immobilized on poly-γ-methyl-L-glutamate. Up to 99% of the cyt.c used was immobilized. This immobilized cyt.c catalyzed N-demethylation, S-oxidation, and epoxidation in the same manner as both P450 and free cyt.c, and the activities of these reactions were increased by the immobilization. In N-demethylation of N, N-dimethylaniline with cumene hydroperoxide (CHP) catalyzed by cyt.c, the Vmax for CHP was increased by 4.4-fold by the immobilization of the enzyme, while the Km remained unchanged. Since P450 is involved in the metabolism of many xenobiotics, the above results suggest that immobilized cyt.c may be useful in drug metabolism research.
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U2 - 10.1006/abbi.1993.1155
DO - 10.1006/abbi.1993.1155
M3 - Article
C2 - 7681661
AN - SCOPUS:0027194319
VL - 301
SP - 355
EP - 360
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
SN - 0003-9861
IS - 2
ER -