Gómez-Cambronero J, Velasco S, Mato J M, Sánchez-Crespo M
Biochim Biophys Acta. 1985 Jun 30;845(3):516-9. doi: 10.1016/0167-4889(85)90219-8.
Incubation of rat splenic microsomes with the catalytic subunit of cyclic AMP-dependent protein kinase in the presence of Mg-ATP stimulated 2-3-fold lyso-platelet-activating factor: acetyltransferase activity. This activation was due to an increase in the Vmax of the acetylation reaction, whereas the Km for acetyl-CoA was not affected. The ATP derivative, AMPPNP, could not replace ATP and preincubation of the microsomes with the heat-stable inhibitor of protein kinase prevented the activation by Mg-ATP obtained in the presence of the protein kinase. Activation of the acetylation reaction by the protein kinase was reversible. Evidence is provided that the reversal of activation is due to dephosphorylation of the enzyme. These data provide evidence that in vitro lyso-platelet-activating factor: acetyltransferase from splenic microsomes is regulated by phosphorylation.
在Mg-ATP存在的情况下，将大鼠脾脏微粒体与环磷酸腺苷依赖性蛋白激酶的催化亚基一起温育，可刺激溶血血小板活化因子：乙酰转移酶活性提高2 - 3倍。这种激活是由于乙酰化反应的Vmax增加，而乙酰辅酶A的Km不受影响。ATP衍生物AMPPNP不能替代ATP，并且用蛋白激酶的热稳定抑制剂对微粒体进行预温育可阻止在蛋白激酶存在下Mg-ATP所导致的激活。蛋白激酶对乙酰化反应的激活是可逆的。有证据表明激活的逆转是由于该酶的去磷酸化。这些数据提供了证据，表明体外脾脏微粒体中的溶血血小板活化因子：乙酰转移酶受磷酸化调节。
