TY - JOUR
T1 - Microsomal alcohol oxygenase
T2 - Purification and characterization of a cytochrome P450 responsible for oxidation of 7-hydroxy-Δ8- tetrahydrocannabinol to 7-oxo-Δ8-tetrahydrocannabinol in guinea pig liver
AU - Matsunaga, Tamihide
AU - Tanaka, Hiroyuki
AU - Komura, Akiko
AU - Watanabe, Kazuhito
AU - Yamamoto, Ikuo
AU - Yoshimura, Hidetoshi
N1 - Funding Information:
1 This work was partially supported by a Grant-in-Aid for Scienti®c Research from the Ministry of Education, Science and Culture of Japan, and by the Special Research Fund of Hokuriku University. 2To whom correspondence should be addressed. Fax: /81-76-229-2781. 3Abbreviations used: MALCO, microsomal alcohol oxygenase; D8-THC, D8-tetrahydrocannabinol; P450, cytochrome P450; DLPC, di-
PY - 1997/12/1
Y1 - 1997/12/1
N2 - Guinea pig hepatic enzyme, microsomal alcohol oxygenase, was able to oxidize both 7α- and 7β-hydroxy-Δ8-tetrahydrocannabinol (7α- and 7β- hydroxy-Δ8-THC) to 7-oxo-Δ8-THC. A cytochrome P450, named P450GPF-B, which mediates this oxidative metabolism was purified from hepatic microsomes of untreated female guinea pigs. The purified enzyme showed a single protein band of molecular mass 50,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The NH2-terminal amino acid sequence of P450GPF-B is highly homologous with those of several cytochrome P450s belonging to the CYP3A subfamily. 18O derived from atmospheric oxygen was incorporated into 31 and 6%, respectively, of 7-oxo-Δ8-THC formed from 7α- and 7β-hydroxy-Δ8- THC when the substrates were incubated with P450GPF-B under 18O2. The antibody against P450GPF-B significantly suppressed the oxidative activities of 7α- and 7β-hydroxy-Δ8-THC to 7-oxo-Δ8-THC in hepatic microsomes of guinea pig. These results indicate that P450GPF-B is a major enzyme responsible for the hepatic microsomal alcohol oxygenase activities in the guinea pig.
AB - Guinea pig hepatic enzyme, microsomal alcohol oxygenase, was able to oxidize both 7α- and 7β-hydroxy-Δ8-tetrahydrocannabinol (7α- and 7β- hydroxy-Δ8-THC) to 7-oxo-Δ8-THC. A cytochrome P450, named P450GPF-B, which mediates this oxidative metabolism was purified from hepatic microsomes of untreated female guinea pigs. The purified enzyme showed a single protein band of molecular mass 50,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The NH2-terminal amino acid sequence of P450GPF-B is highly homologous with those of several cytochrome P450s belonging to the CYP3A subfamily. 18O derived from atmospheric oxygen was incorporated into 31 and 6%, respectively, of 7-oxo-Δ8-THC formed from 7α- and 7β-hydroxy-Δ8- THC when the substrates were incubated with P450GPF-B under 18O2. The antibody against P450GPF-B significantly suppressed the oxidative activities of 7α- and 7β-hydroxy-Δ8-THC to 7-oxo-Δ8-THC in hepatic microsomes of guinea pig. These results indicate that P450GPF-B is a major enzyme responsible for the hepatic microsomal alcohol oxygenase activities in the guinea pig.
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U2 - 10.1006/abbi.1997.0390
DO - 10.1006/abbi.1997.0390
M3 - Article
C2 - 9390174
AN - SCOPUS:0031543445
SN - 0003-9861
VL - 348
SP - 56
EP - 64
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
IS - 1
ER -