Nishimaki T, Yamanaka H, Mizugaki M
J Biochem. 1986 Feb;99(2):365-74. doi: 10.1093/oxfordjournals.jbchem.a135491.
Crude extract of Escherichia coli was found to elongate medium chain acyl-CoA primers. The reaction products were fatty acids one or two C2 units longer than the primer. Acetyl-CoA acted as the condensing unit in this reaction, while malonyl-CoA did not. The optimal pH for the reaction was 5.0 in 0.1 M citrate-phosphate buffer. NADH was the predominant electron donor for the incorporation of acetyl-CoA into fatty acids, and NADPH was one-third as effective as NADH at pH 5.0. Acyl carrier protein and cerulenin had no effect on the acetyl-CoA incorporation into the chain elongation products. Acyl-CoA compounds with medium carbon chain lengths proved to be the best as primers, and the maximum incorporation was observed with octanoyl-CoA. N-Ethylmaleimide and p-hydroxymercuribenzoate blocked the chain elongation reaction by inhibiting either condensation or 3-ketoacyl reduction.
发现大肠杆菌的粗提取物能使中链酰基辅酶A引物延长。反应产物是比引物长一个或两个C2单元的脂肪酸。在该反应中，乙酰辅酶A作为缩合单元，而丙二酰辅酶A则不然。在0.1M柠檬酸-磷酸盐缓冲液中，该反应的最佳pH值为5.0。NADH是将乙酰辅酶A掺入脂肪酸的主要电子供体，在pH 5.0时，NADPH的效力是NADH的三分之一。酰基载体蛋白和浅蓝菌素对乙酰辅酶A掺入链延长产物没有影响。中等碳链长度的酰基辅酶A化合物被证明是最好的引物，用辛酰辅酶A时观察到最大掺入量。N-乙基马来酰亚胺和对羟基汞苯甲酸通过抑制缩合或3-酮酰基还原而阻断链延长反应。
