N-ACYLATION OF ETHANOLAMINE PHOSPHOLIPIDS IN CANINE MYOCARDIUM
N-ACYLATION OF ETHANOLAMINE PHOSPHOLIPIDS IN CANINE MYOCARDIUM
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DOI：
10.1016/0005-2760(82)90352-6
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发表时间：
1982-01-01
期刊：
影响因子：
--
通讯作者：
SCHMID, HHO
中科院分区：
文献类型：
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作者：
NATARAJAN, V;REDDY, PV;SCHMID, HHO
N-酰基乙醇胺磷脂，这是发现在梗塞，而不是在正常犬心肌，产生的正常心肌组织的制剂中孵育的存在下，毫摩尔浓度的Ca ~（2+）。内源性底物的生物合成活性与微粒体和线粒体组分，并表现出碱性pH值的最佳。用[1，2 - 14 C]乙醇胺脉冲标记心肌乙醇胺磷脂后，观察N-酰基乙醇胺磷脂合成和降解的时间过程。磷脂酰乙醇胺和溶血磷脂酰乙醇胺的酶促N-酰化被证明通过孵育这些底物与心肌组织匀浆。无论是游离脂肪酸，也不酰基辅酶A衍生物作为酰基供体，但外源性磷脂酰乙醇胺的一些组成脂肪酸之间的N-酰基乙醇胺磷脂的酰胺连接的脂肪酸被回收。因此，N-酰化可以通过由Ca 2+依赖性转酰酶催化的O-酰基转移而发生。由于N-酰基乙醇胺磷脂是具有生物活性的N-酰基乙醇胺的前体，它们的生物合成可能构成旨在保护缺血心肌组织的重要损伤诱导的代谢事件。
N-Acylethanolamine phospholipids, which are found in infarcted but not in normal canine myocardium, were produced by preparations of normal myocardial tisue incubated in the presence of millimolar concentrations of Ca2+. Biosynthetic activity from endogenous substrates was associated with both microsomal and mitochondrial fractions and exhibited an alkaline pH optimum. The time course of N-acylethanolamine phospholipid synthesis and degradation was followed after pulse labeling of myocardial ethanolamine phospholipids with [1,2-14C]ethanolamine. Enzymic N-acylation of both phosphatidylethanolamine and lysophosphatidylethanolamine was demonstrated by incubating these substrates with homogenates of myocardial tissue. Neither free fatty acids nor acyl-CoA derivatives served as acyl donor, but some of the constituent fatty acids of exogenous phosphatidylethanolamine were recovered among the amide-linked fatty acids of the N-acylethanolamine phospholipids. N-Acylation may thus occur by the transfer of O-acyl groups catalyzed by a Ca2+-dependent transacylase. Since N-acylethanolamine phospholipids are precursors of the biologically active N-acylethanolamines, their biosynthesis may constitute an important injury-induced metabolic event aimed at the protection of ischemic myocardial tissue.