Zaror-Behrens G, Kako K J
Biochim Biophys Acta. 1976 Jul 20;441(1):1-13. doi: 10.1016/0005-2760(76)90275-7.
Fatty acid selectivity of acyl-CoA:glycerol-3-phosphate acyltransferase (EC 2.3.1.15) and acyl-CoA:monoacylglycerol-3-phosphate acyltransferase (EC 2.3.1.52) of the microsomal fraction prepared from rabbit heart was studied. 1. The rate of acylation of glycerol 3-phosphate was increased proportionally with the concentration of acyl-CoA. The maximum rate was reached at 0.3 mumol acyl-CoA per ml. Palmitoyl-, oleoyl- and linoleoyl-CoA all served equally well as acyl donors, and produced approximately equal amounts of mono- and diacylglycerol 3-phosphate. The rate of reaction measured in the presence of two acyl-CoA esters was similar to that in the presence of a single acyl-CoA. 2. Treatment of synthesized monoacylglycerol 3-phosphate with Crotalus adamanteus venom phospholipase A2 (EC 3.1.1.4) and that with phosphatidate phosphatase (EC 3.1.3.4) indicated that the heart enzyme synthesized almost exclusively 1-acylglycerol 3-phosphate regardless of the kind of acyl donor. 3. Hydrolysis of diacylglycerol 3-phosphate with phospholipase A2 revealed that there was a slight preference for linoleoyl-CoA at position 2 and a slight discrimination against palmitoyl- and stearoyl-CoA at position 2, when diacylglycerol 3-phosphate was synthesized in the presence of a mixture of acyl-CoA esters. When diacylglycerol 3-phosphate was formed in the presence of a single acyl-CoA, the fatty acid distribution was random. 4. The rate of acylation of 1-palmitoylglycerol 3-phosphate by rabbit heart microsomal fraction was increased proportionally to the increasing concentrations of 1-palmitoylglycerol 3-phosphate up to 50 nmol per ml; higher concentrations were inhibitory. Differences in the activities measured with palmitoyl-, oleoyl- and linoleoyl-CoA as acyl donors were negligible. When stearoyl-, arachidonoyl- and erucoyl-CoA acted as acyl donors, the rates of reaction were low. 5. The acyl-CoA:1-palmitoylglycerol-3-phosphate acyltransferase activity increased proportionally to the increasing concentrations of acyl-CoA up to 10 nmol per ml; acyl donor specificity was similar to that found above [4]. The acyltransferase showed
研究了从兔心脏制备的微粒体部分的酰基辅酶A：甘油-3-磷酸酰基转移酶（EC 2.3.1.15）和酰基辅酶A：单酰甘油-3-磷酸酰基转移酶（EC 2.3.1.52）的脂肪酸选择性。1.甘油3-磷酸的酰化速率随酰基辅酶A浓度成比例增加。每毫升0.3微摩尔酰基辅酶A时达到最大速率。棕榈酰辅酶A、油酰辅酶A和亚油酰辅酶A作为酰基供体的效果相同，并产生大致等量的单酰甘油3-磷酸和二酰甘油3-磷酸。在两种酰基辅酶A酯存在下测得的反应速率与在单一酰基辅酶A存在下的反应速率相似。2.用金刚背响尾蛇毒液磷脂酶A2（EC 3.1.1.4）处理合成的单酰甘油3-磷酸以及用磷脂酸磷酸酶（EC 3.1.3.4）处理表明，无论酰基供体的种类如何，心脏酶几乎只合成1-酰基甘油3-磷酸。3.用磷脂酶A2水解二酰甘油3-磷酸表明，当在酰基辅酶A酯混合物存在下合成二酰甘油3-磷酸时，在2位对亚油酰辅酶A有轻微偏好，对2位的棕榈酰辅酶A和硬脂酰辅酶A有轻微排斥。当在单一酰基辅酶A存在下形成二酰甘油3-磷酸时，脂肪酸分布是随机的。4.兔心脏微粒体部分对1-棕榈酰甘油3-磷酸的酰化速率随1-棕榈酰甘油3-磷酸浓度增加而成比例增加，直至每毫升50纳摩尔；更高浓度具有抑制作用。以棕榈酰辅酶A、油酰辅酶A和亚油酰辅酶A作为酰基供体测得的活性差异可忽略不计。当硬脂酰辅酶A、花生四烯酰辅酶A和芥酰辅酶A作为酰基供体时，反应速率较低。5.酰基辅酶A：1-棕榈酰甘油-3-磷酸酰基转移酶活性随酰基辅酶A浓度增加而成比例增加，直至每毫升10纳摩尔；酰基供体特异性与上述[4]中发现的相似。该酰基转移酶显示
