Foot M, Jeffcoat R, Russell N J
Biochem J. 1983 Feb 1;209(2):345-53. doi: 10.1042/bj2090345.
The delta 9-desaturase of the psychrophilic bacterium Micrococcus cryophilus is shown to be a membrane-bound enzyme that is probably linked to a cyanide- (and azide-) sensitive respiratory chain with oxygen as the final acceptor. It has a pH optimum of 8.7 and contains an essential thiol group, but has no special ion requirements. The desaturase activity of washed membranes could not be increased by adding supernatant or NADH and NADPH, possibly owing to the endogenous generation of reduced cofactors by the membranes. The substrate for the desaturase is not acyl-CoA and is probably not acyl-acyl-carrier protein. Evidence is presented that the substrate in vivo is saturated phospholipid and a scheme for the possible routes of incorporation of exogenous stearic acid into oleoyl-phospholipid is presented.
嗜冷细菌嗜冷微球菌的δ9-去饱和酶被证明是一种膜结合酶，可能与以氧为最终受体的对氰化物（和叠氮化物）敏感的呼吸链相连。其最适pH为8.7，含有一个必需的巯基，但没有特殊的离子需求。洗涤过的膜的去饱和酶活性不能通过添加上清液或NADH和NADPH来提高，这可能是由于膜内源性产生还原型辅因子。去饱和酶的底物不是酰基辅酶A，可能也不是酰基-酰基载体蛋白。有证据表明体内的底物是饱和磷脂，并提出了外源性硬脂酸掺入油酰磷脂的可能途径的方案。
