Saari J C, Bredberg D L
Department of Ophthalmology, School of Medicine, University of Washington, Seattle 98195.
J Biol Chem. 1989 May 25;264(15):8636-40.
Microsomal preparations from retinal pigment epithelium carry out phosphatidylcholine synthesis upon incubation with 1-palmitoyllysophosphatidylcholine and fatty acyl-CoA. Phosphatidylcholine synthesized in situ in this manner is an acyl donor for retinyl ester synthesis, demonstrating the existence of lecithin:retinol acyltransferase. Although acyl transfer to retinol is from the 1-position of phosphatidylcholine, the fatty acid in the 2-position is important in substrate recognition. The finding of this novel enzyme activity in retinal pigment epithelial microsomes suggests that phosphatidylcholine is the endogenous acyl donor in CoA-independent retinol esterification observed in these preparations.
视网膜色素上皮的微粒体制剂在与1-棕榈酰溶血磷脂酰胆碱和脂肪酰辅酶A一起孵育时会进行磷脂酰胆碱的合成。以这种方式原位合成的磷脂酰胆碱是视黄酯合成的酰基供体，证明了卵磷脂：视黄醇酰基转移酶的存在。尽管酰基向视黄醇的转移来自磷脂酰胆碱的1位，但2位的脂肪酸在底物识别中很重要。在视网膜色素上皮微粒体中发现这种新的酶活性表明，磷脂酰胆碱是在这些制剂中观察到的不依赖辅酶A的视黄醇酯化反应中的内源性酰基供体。
