Kim Y S, Lee J K
J Biol Chem. 1986 Dec 15;261(35):16295-7.
The isolation of malonyl-coenzyme A synthetase from Pseudomonas fluorescens grown on malonate has been reported recently (Kim, Y.S., and Bang, S.K. (1985) J. Biol.Chem. 260, 5098-5104). This enzyme is phosphorylated in the presence of ATP and Mg2+. The phosphoryl group appears on one subunit of the enzyme composed of two different subunits, and the phosphoryl enzyme is acid labile and base stable. The phosphoryl group on the enzyme is released by the incubation of the phosphoryl enzyme with malonate and malonyl enzyme is formed. The malonyl enzyme is acid labile and also relatively unstable under basic conditions. The malonyl group is found on the subunit of the enzyme which is phosphorylated. Malonyl-CoA is formed when malonyl enzyme reacts with coenzyme A. These results suggest that two convalent intermediates, phosphoryl and malonyl enzyme, are sequentially formed in the synthesis of malonyl-coenzyme A by malonyl-coenzyme A synthetase catalysis.
最近报道了从在丙二酸上生长的荧光假单胞菌中分离出丙二酰辅酶A合成酶（Kim, Y.S., 和Bang, S.K. (1985) J. Biol.Chem. 260, 5098 - 5104）。该酶在ATP和Mg2+存在下会发生磷酸化。磷酸基团出现在由两个不同亚基组成的酶的一个亚基上，磷酸化酶对酸不稳定而对碱稳定。通过将磷酸化酶与丙二酸一起温育可释放酶上的磷酸基团，并形成丙二酰酶。丙二酰酶对酸不稳定，在碱性条件下也相对不稳定。丙二酰基团存在于发生磷酸化的酶亚基上。当丙二酰酶与辅酶A反应时会形成丙二酰辅酶A。这些结果表明，在丙二酰辅酶A合成酶催化合成丙二酰辅酶A的过程中，依次形成了两种共价中间体，即磷酸化酶和丙二酰酶。
