Cytochromes P450 catalyze oxidation of α,β-unsaturated aldehydes
Cytochromes P450 catalyze oxidation of α,β-unsaturated aldehydes
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DOI：
10.1016/j.abb.2007.05.019
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发表时间：
2007-08-15
影响因子：
3.9
通讯作者：
Prough, Russell A.
中科院分区：
文献类型：
--
作者：
Amunom, Immaculate;Stephens, Laura J.;Prough, Russell A.
我们试图确定血红素硫酸酯单加氧酶是否氧化脂质过氧化过程中产生的a， α， β -不饱和醛。研究了几种与NADPH:P450氧化还原酶共表达的重组P450对蒽-9-甲醛和4-羟基反式-2-烯醛（HNE）的醛氧化活性。小鼠P4502c29、人P4503A4、人P4502B6和兔P4502B4是醛氧化制羧酸的良好催化剂。其他p450（如P4501A2、2EI和2J2）不能氧化这些醛。P4502c29和P4503A4显示的K-m/S-0.5值约为。1 ~ 20 μ M.与正品4-羟基壬烯酸（HNA）共迁移的HPLC测定产物的质谱与标准一致。对于P4502c29， HNE是一种混合竞争的蒽-9-甲醛氧化抑制剂，这表明这两种醛都是P4502c29的底物。我们使用醛脱氢酶和P450特异性抑制剂来评估它们在原代大鼠肝细胞HNE代谢中的作用。醛脱氢酶（氰酰胺）抑制剂抑制60%的海航形成，氰酰胺和咪康唑（P450）共同抑制85%以上的海航形成。p450是大鼠原代肝细胞内源性和外源性不饱和醛代谢的重要参与者。(c) 2007爱思唯尔公司版权所有。
We sought to establish whether heme-thiolate monooxygenases oxidize, a,alpha,beta-unsaturated aldehydes generated during lipid peroxidation. Several recombinant P450s co-expressed with NADPH:P450 oxidoreductase were surveyed for aldehyde oxidation activity with anthracene-9-carboxaldehyde and 4-hydroxy-trans-2-notienal (HNE). Murine P4502c29, human P4503A4, human P4502B6, and rabbit P4502B4 were good catalysts of aldehyde oxidation to carboxylic acids. Other P450s (e.g., P4501A2, 2EI, and 2J2) did not oxidize these aldehydes. P4502c29 and P4503A4 displayed K-m/S-0.5 values of approx. 1-20 mu M. The product measured by HPLC that co-migrates with authentic 4-hydroxynonenoic acid (HNA) had a mass spectrum identical to the standard. Using P4502c29, HNE was a mixed-competitive inhibitor of anthracene-9-carboxaldehyde oxidation, suggesting that both aldehydes are substrates for P4502c29. Specific inhibitors of aldehyde dehydrogenases and P450 were used to assess their role in the metabolism of HNE in primary rat hepatocytes. Inhibitors of aldehyde dehydrogenase (cyanamide) inhibited HNA formation by 60% and together cyanamide and miconazole (P450) caused over 85% inhibition of HNA formation. P450s are significant participants in metabolism of endogenous and exogenous unsaturated aldehydes in primary rat hepatocytes. (c) 2007 Elsevier Inc. All rights reserved.