Jonas A, Zorich N L, Kézdy K E, Trick W E
J Biol Chem. 1987 Mar 25;262(9):3969-74.
Complexes of phospholipids-apolipoprotein A-I-cholesterol, containing various bulk phosphatidylcholines or a matrix of the ether analog of 1-palmitoyl 2-oleoyl phosphatidylcholine including test phosphatidylcholines were used as substrates for human lecithin-cholesterol acyltransferase. The enzymatic reaction rates for both series of complexes were determined as a function of temperature, particle concentration, neutral salt concentration, and the type of anion present in solution. The kinetic results support the hypothesis that phospholipids, in discoidal complexes, modulate the reaction rates by molecular effects at the active site, but also by interfacial effects on the interaction of the enzyme with the particles. The relevant interfacial parameters are the lipid packing at the interface and the structure of apolipoprotein A-I.
含有各种大量磷脂酰胆碱或包括测试磷脂酰胆碱在内的1-棕榈酰-2-油酰磷脂酰胆碱醚类似物基质的磷脂-载脂蛋白A-I-胆固醇复合物被用作人卵磷脂胆固醇酰基转移酶的底物。测定了这两个系列复合物的酶促反应速率与温度、颗粒浓度、中性盐浓度以及溶液中存在的阴离子类型的函数关系。动力学结果支持以下假设：在盘状复合物中的磷脂通过活性位点的分子效应以及对酶与颗粒相互作用的界面效应来调节反应速率。相关的界面参数是界面处的脂质堆积和载脂蛋白A-I的结构。
