Matsui K, Shibutani M, Hase T, Kajiwara T
Department of Biological Chemistry, Faculty of Agriculture, Yamaguchi University, Japan.
FEBS Lett. 1996 Sep 23;394(1):21-4. doi: 10.1016/0014-5793(96)00924-6.
Fatty acid hydroperoxide lyases cleave a C-C bond adjacent to a hydroperoxide group in lipoxygenase derived lipid hydroperoxides to form short-chain aldehydes and oxo-acids. Previously, we showed that fatty acid hydroperoxide lyase from bell pepper fruits is a heme protein whose spectrophotometric properties greatly resemble a cytochrome P450. In order to ascertain the relationship of it to the P450 gene family, we have cloned cDNA encoding fatty acid hydroperoxide lyase from immature bell pepper fruits. The cDNA encodes 480 amino acids, and shares homology with P450s mostly at the C terminus. The heme binding cysteine is recognizable at position 441. The most closely related P450 is allene oxide synthase (CYP74A), with which it has 40% identity. It qualifies the lyase as a member of a new P450 subfamily, CYP74B. From this finding, the enzyme is thought to be a novel member of P450 specialized for the metabolism of lipid peroxides.
脂肪酸氢过氧化物裂解酶可裂解脂氧合酶衍生的脂质氢过氧化物中与氢过氧化物基团相邻的碳 - 碳键，以形成短链醛和氧代酸。此前，我们发现甜椒果实中的脂肪酸氢过氧化物裂解酶是一种血红素蛋白，其分光光度特性与细胞色素P450极为相似。为了确定其与P450基因家族的关系，我们从未成熟的甜椒果实中克隆了编码脂肪酸氢过氧化物裂解酶的cDNA。该cDNA编码480个氨基酸，并且主要在C末端与P450具有同源性。在第441位可识别出血红素结合半胱氨酸。与之关系最密切的P450是丙二烯氧化物合酶（CYP74A），它们的一致性为40%。这使得该裂解酶成为一个新的P450亚家族CYP74B的成员。基于这一发现，该酶被认为是专门用于脂质过氧化物代谢的P450新成员。
