Sanjanwala M, Sun G Y, MacQuarrie R A
School of Basic Life Sciences, University of Missouri, Kansas City 64110.
Arch Biochem Biophys. 1987 Nov 1;258(2):299-306. doi: 10.1016/0003-9861(87)90348-1.
Long-chain acyl-CoA hydrolase (EC 3.1.2.2) has been purified 12,000-fold from bovine heart muscle microsomes by extraction with Miranol detergent, followed by column chromatography on Reactive Blue agarose and DEAE-cellulose. The purified enzyme was nearly homogeneous on polyacrylamide gel electrophoresis and had a molecular weight of 41,000 in the presence of dodecyl sulfate. The specificity and kinetic properties of the enzyme were studied using several acyl-CoA derivatives as potential substrates. The enzyme showed a wide degree of specificity with little dependence on either the fatty acyl chain length or the degree of unsaturation of the acyl group. The kinetic properties were in accord with the Michaelis-Menten equation under most conditions, although high concentrations of substrates generally inhibited the enzyme. Arachidonoyl-CoA, which was the most effective substrate, had a Km value of 0.4 microM and a Vmax value of 6.0 mumol min-1 mg-1. The enzyme was strongly and specifically inhibited by constants of 16 and 30 nM, respectively. Other lysolipids and detergents such as deoxycholate and Triton X-100 were weak inhibitors. These properties and others distinguish this enzyme from other acyl-CoA hydrolases and support the idea that lysophospholipids may be important in vivo in the regulation of lipid metabolism.
长链脂酰辅酶A水解酶（EC 3.1.2.2）已通过用米腊诺洗涤剂从牛心肌微粒体中提取，随后在活性蓝琼脂糖和二乙氨基乙基纤维素柱上进行层析，从牛心肌微粒体中纯化了12000倍。纯化后的酶在聚丙烯酰胺凝胶电泳上几乎呈均一状态，在十二烷基硫酸钠存在下分子量为41000。使用几种脂酰辅酶A衍生物作为潜在底物研究了该酶的特异性和动力学性质。该酶表现出广泛的特异性，对脂肪酰链长度或酰基不饱和度的依赖性很小。在大多数情况下，动力学性质符合米氏方程，尽管高浓度底物通常会抑制该酶。最有效的底物花生四烯酰辅酶A的Km值为0.4微摩尔，Vmax值为6.0微摩尔·分钟-1·毫克-1。该酶分别被16和30纳摩尔的常数强烈且特异性地抑制。其他溶血磷脂和洗涤剂如脱氧胆酸盐和曲拉通X-100是弱抑制剂。这些性质以及其他特性使该酶与其他脂酰辅酶A水解酶区分开来，并支持溶血磷脂在体内可能对脂质代谢调节很重要的观点。
