Carnitine palmitoyltransferase in human erythrocyte membrane. Properties and malonyl-CoA sensitivity.
Carnitine palmitoyltransferase in human erythrocyte membrane. Properties and malonyl-CoA sensitivity.
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人红细胞膜中的肉碱棕榈酰转移酶。
DOI：
10.1042/bj2750685
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
Arduini,A
中科院分区：
文献类型：
--
作者：
Ramsay,RR;Mancinelli,G;Arduini,A
位于红细胞质膜上的肉毒碱棕榈酰转移酶对丙二酰辅酶A和2-溴棕榈酰辅酶A加肉毒碱的抑制敏感。虽然这种抑制和其他性质表明在其他组织中的细胞内酶的相似性，没有交叉反应，观察到与抗血清的过氧化物酶体或线粒体内膜酶。该活性被Triton X-100溶解并在Triton X-100中稳定，Triton X-100可破坏微粒体和线粒体外膜中发现的酶。底物特异性比胞内酶更宽，硬脂酰-CoA（114%）和花生四烯酸酰-CoA（97%）的活性与棕榈酰-CoA的活性相等，亚油酰-CoA（44%）和芥酸酰-CoA（46%）的活性约为棕榈酰-CoA的一半。这种肉毒碱棕榈酰转移酶的功能可能是缓冲存在于红细胞中的酰基辅酶A，用于膜脂质的脂肪酰基的周转。
Carnitine palmitoyltransferase located in the erythrocyte plasma membrane is sensitive to inhibition by malonyl-CoA and 2-bromopalmitoyl-CoA plus carnitine. Although this inhibition and other properties suggest similarities to the intracellular enzymes in other tissues, no cross-reaction was observed with antisera to the peroxisomal or to the mitochondrial inner-membrane enzyme. The activity was solubilized by and was stable in Triton X-100, which destroys the enzymes found in microsomes and in the mitochondrial outer membrane. The substrate specificity is broader than for the intracellular enzymes, the activities with stearoyl-CoA (114%) and arachidonoyl-CoA (97%) being equal to that with palmitoyl-CoA, and the activities with linoleoyl-CoA (44%) and erucoyl-CoA (46%) about half that with palmitoyl-CoA. The function of this carnitine palmitoyltransferase is probably to buffer the acyl-CoA present in the erythrocyte for turnover of the fatty acyl groups of the membrane lipids.