Reynolds K A, Wang P, Fox K M, Speedie M K, Lam Y, Floss H G
Department of Biomedicinal Chemistry, School of Pharmacy, University of Maryland, Baltimore 21201.
J Bacteriol. 1992 Jun;174(12):3850-4. doi: 10.1128/jb.174.12.3850-3854.1992.
A novel NADPH-dependent enoyl reductase, catalyzing the conversion of 1-cyclohexenylcarbonyl coenzyme A (1-cyclohexenylcarbonyl-CoA) to cyclohexylcarbonyl-CoA, was purified to homogeneity from Streptomyces collinus. This enzyme, a dimer with subunits of identical M(r) (36,000), exhibits a Km of 1.5 +/- 0.3 microM for NADPH and 25 +/- 3 microM for 1-cyclohexenylcarbonyl-CoA. It has a pH optimum of 7.5, is most active at 30 degrees C, and is inhibited by both divalent cations and thiol reagents. Two internal peptide sequences were obtained. Ansatrienin A (an antibiotic produced by S. collinus) contains a cyclohexanecarboxylic acid moiety, and it is suggested that the 1-cyclohexenylcarbonyl-CoA reductase described herein catalyzes the final reductive step in the conversion of shikimic acid into this moiety.
从链霉菌中纯化得到一种新型的依赖烟酰胺腺嘌呤二核苷酸磷酸（NADPH）的烯酰还原酶，该酶可催化1-环己烯基羰基辅酶A（1-cyclohexenylcarbonyl-CoA）转化为环己基羰基辅酶A，并达到了均一性。这种酶是一种二聚体，其亚基的相对分子质量（M(r)）相同（36,000），对NADPH的Km值为1.5±0.3微摩尔，对1-环己烯基羰基辅酶A的Km值为25±3微摩尔。其最适pH为7.5，在30℃时活性最高，并且受到二价阳离子和硫醇试剂的抑制。获得了两条内部肽段序列。安丝菌素A（链霉菌产生的一种抗生素）含有环己烷羧酸部分，本文所述的1-环己烯基羰基辅酶A还原酶被认为催化了莽草酸转化为该部分的最后一步还原反应。
