Jiang D W, Englund P T
Department of Biological Chemistry, Johns Hopkins Medical School, 725 N. Wolfe St., Baltimore, MD 21205, USA.
Biochem J. 2001 Sep 15;358(Pt 3):757-61. doi: 10.1042/0264-6021:3580757.
As part of our investigation of fatty acid metabolism in Trypanosoma brucei, we have expressed four acyl-CoA synthetase (TbACS) genes in Esherichia coli. The recombinant proteins, with His-tags on their C-termini, were purified to near homogeneity using nickel-chelate affinity chromatography. Although these enzymes are highly homologous, they have distinct specificities for fatty acid chain length. TbACS1 prefers saturated fatty acids in the range C(11:0) to C(14:0) and TbACS2 prefers shorter fatty acids, mainly C(10:0). TbACS3 and 4, which have 95% sequence identity, have similar specificities, favouring fatty acids between C(14:0) and C(17:0). In addition, TbACS1, 3 and 4 function well with a variety of unsaturated fatty acids.
作为我们对布氏锥虫脂肪酸代谢研究的一部分，我们已在大肠杆菌中表达了四个酰基辅酶A合成酶（TbACS）基因。这些重组蛋白的C末端带有His标签，通过镍螯合亲和层析纯化至近乎同质。尽管这些酶具有高度同源性，但它们对脂肪酸链长度具有不同的特异性。TbACS1偏爱C(11:0)至C(14:0)范围内的饱和脂肪酸，而TbACS2偏爱较短的脂肪酸，主要是C(10:0)。具有95%序列同一性的TbACS3和4具有相似的特异性，倾向于C(14:0)至C(17:0)之间的脂肪酸。此外，TbACS1、3和4对多种不饱和脂肪酸也能很好地发挥作用。
