Ferrer A, Caelles C, Massot N, Hegardt F G
Biochem Biophys Res Commun. 1985 Oct 30;132(2):497-504. doi: 10.1016/0006-291x(85)91161-1.
Inactivation of 3-hydroxy-3-methylglutaryl Coenzyme A reductase by reductase kinase and ATP-Mg needs either ADP or 5'-AMP as cofactors. 5'-AMP is a more potent activator of cytosolic reductase kinase than ADP. This capacity is expressed by increasing not only the rate of reductase inactivation, but also the rate of reductase phosphorylation from [gamma-32P]ATP. Activation constants, Ka, for 5'-AMP and ADP are 20 microM and 420 microM respectively. Neither 3'-AMP nor 2'-AMP activate reductase kinase. Other nucleoside monophosphates like UMP, CMP and GMP cannot replace 5'-AMP as activators of reductase kinase.
还原酶激酶和ATP-Mg使3-羟基-3-甲基戊二酰辅酶A还原酶失活需要ADP或5'-AMP作为辅因子。5'-AMP比ADP更有效地激活胞质还原酶激酶。这种能力不仅通过提高还原酶失活速率来体现，还通过提高[γ-32P]ATP对还原酶的磷酸化速率来体现。5'-AMP和ADP的激活常数Ka分别为20微摩尔和420微摩尔。3'-AMP和2'-AMP均不能激活还原酶激酶。其他核苷单磷酸如UMP、CMP和GMP不能替代5'-AMP作为还原酶激酶的激活剂。
