Analyzes of Structure and Function of Novel Carbonyl Metabolic Enzymes : MALDO and MALCO

从小鼠、豚鼠和日本猴的肝微粒体中分离纯化了3种P450同工酶，分别命名为P450MDX-A、P450GPF-A和P450JM-C，它们是9-蒽醛微体加氧酶(MALDO)的主要同工酶。这些同工酶的N端氨基酸序列表明，这些同工酶是CYP2B亚家族的成员。胡椒醛、α-正戊基肉桂醛、香草醛和甲苯醛也被小鼠肝脏MALDO氧化为相应的羧酸。从小鼠、豚鼠和雌性日本猴的肝微粒体中纯化了3种P450同工酶，分别命名为P450MDX-B、P450GPF-B和P450JM-E，它们是7-OH-Delta、8-四氢大麻酚微粒醇加氧酶(MALCO)活性的主要同工酶。同工酶的N端氨基酸序列分析表明，该同工酶属于细胞色素P450亚家族成员。该基因命名为Cyp2c-29(129)，可能与C57BL/6小鼠肝脏cDNA文库中Cyp2c-29的一个多态变异相对应。6个核苷酸变化中有1个是非保守的，导致Cyp2c-29(C57BL/6)的106个Ile被104 Met取代。与Cyp2c-29序列的比较显示，4个差异集中在位于228-405的174个核苷酸序列中。用RT-PCR法从C57BL/6、DDN、Ddy、C3H、DBA/2和ICR小鼠肝脏中扩增出与该区域(188-445)对应的mRNAs，扩增出的核苷酸序列除C57BL/6外与Cyp2c-29(129)相同。该基因的核苷酸序列与CYP3A-11的核苷酸序列一致。

Three P450 isozymes, named P450MDX-A,P450GPF-A and P450JM-C,which are major isozymes responsible for 9-anthraldehyde microsomal aldehyde oxygenase (MALDO) activity were purified from hepatic microsomes of mice, guinea pigs and Japanese monkeys. The N-terminal amino acid sequences of these isozymes suggest that the isozymes are member of CYP2B subfamily. Piperonal, alpha-n-amylcinnamaldehyde, vanillin and tolaldehyde were also oxidized to the corresponding carboxylic acids by MALDO of mouse liver.Three P450 isozymes, named P450MDX-B,P450GPF-B and P450JM-E,which are major isozymes responsible for 7-OH-DELTA^8-tetrahydrocannabinol microsomal alcohol oxygenase (MALCO) activity were purified from hepatic microsomes of mice, guinea pigs and female Japanese monkeys. The N-terminal amino acid sequences of these isozymes suggest that the isozymes are member of CYP3A subfamily.A cDNA encoding a P450 isozyme was isolated from a cDNA library constructed from male 129 mouse liver. The cDNA,designated Cyp2c-29 (129), may correspond to a polymorphic variant of Cyp2c-29 (isolated from C57BL/6 mouse liver cDNA library). One out of the six nucleotide changes is nonconservative, resulting in the replacement of 106 Ile of Cyp2c-29 (C57BL/6) by 104 Met. The comparison with Cyp2c-29 sequence shows 4 differences concentrated within a 174-nucleotide sequence located 228-405. mRNAs corresponding to this region (188-445) in C57BL/6, ddN,ddY,C3H,DBA/2 and ICR mouse livers were amplified by the methods of RT-PCR.The amplified nucleotide sequences were the identical with those of Cyp2c-29 (129) except for C57BL/6. A cDNA clone encoding P450MDX-B was isolated from a mouse liver cDNA library. The nucleotide sequence of the cDNA is identical to that of Cyp3a-11.