Paltauf F
Eur J Biochem. 1978 Apr;85(1):263-70. doi: 10.1111/j.1432-1033.1978.tb12235.x.
The terminal step during aerobic plasmalogen biosynthesis is catalyzed by a microsomal desaturase system which converts 1-O-alkyl-2-acyl-sn-glycerophosphoethanolamine to 1-O-alk-1'-enyl-2-acyl-sn-glycerophosphoethanolamine (ethanolamine plasmalogen). The reaction depends on oxygen and NAD(P)H and is stimulated 3-10-fold by soluble activating factors contained in the 100 000 X g supernatant. Two stimulating proteins have been isolated from pig kidney; the partially purified proteins have identical molecular weights (27 000) but differ in their respective isoelectric points (protein I, 5.1 and protein II, 4.9). Both proteins behave identically in the biochemical studies conducted. Exogenous substrate binds to the stimulating proteins; the transfer of ethanolamine, but not of choline phospholipids, from liposomes to microsomes is enhanced by the stimulating proteins. They stimulate plasmalogen synthesis from either exogenous or endogenous substrate (synthesized from alkylglycerophosphoethanolamine by microsomal transacylases). The stimulating proteins have no enzymatic activity themselves; it is suggested that they affect events within the membrane and function as specific mediators between the membrane-bound enzyme system and the lipophilic substrate.
有氧缩醛磷脂生物合成的最后一步由微粒体去饱和酶系统催化，该系统将1-O-烷基-2-酰基-sn-甘油磷酸乙醇胺转化为1-O-烯基-1'-烯基-2-酰基-sn-甘油磷酸乙醇胺（乙醇胺缩醛磷脂）。该反应依赖于氧气和NAD(P)H，并受到100000×g上清液中可溶性激活因子的3至10倍刺激。已从猪肾中分离出两种刺激蛋白；部分纯化的蛋白具有相同的分子量（27000），但各自的等电点不同（蛋白I为5.1，蛋白II为4.9）。在进行的生化研究中，这两种蛋白表现相同。外源性底物与刺激蛋白结合；刺激蛋白可增强乙醇胺（而非胆碱磷脂）从脂质体向微粒体的转移。它们可刺激外源性或内源性底物（由微粒体转酰基酶从烷基甘油磷酸乙醇胺合成）合成缩醛磷脂。刺激蛋白本身没有酶活性；有人认为它们影响膜内的事件，并作为膜结合酶系统和亲脂性底物之间的特异性介质发挥作用。
