粉防已碱与红细胞膜ATPase相互作用的研究

粉防已碱是一种新的钙调蛋白拮抗剂,专一性抑制人红细胞膜上依赖CaM的Ca~(2+)-Mg~(2+)-ATPase。在较高浓度下,它也不同程度地抑制Ca~(2+)-Mg~(2+)-ATPase基本活性、Na~+-K~+-ATPase和Mg~(2+)-ATPase的活性。 除CaM外,不饱和脂肪酸和有限水解均导致膜Ca~(2+)-Mg~(2+)-ATPase的活化,所有这些活化作用被Tet在大约相同的浓度范围内抑制,表明Tet除与CaM结合外,也与膜Ca~(2+)-Mg~(2+)-ATPase结合。 Tet具有抗抵渗溶血的性能,反映了拮抗CaM与药物的膜稳定性间存在相关性。

THE INTERACTION OF TETRANDRINE WITH ERYTHROCYTE MEMBRANE ATPase

Tetrandrine is a new calmodulin antagonist.It can specifically inhibite CaM-stimulated Ca2 -Mg2 -ATPase in human erythrocyte membrane.At higher concentration of Tet,it also inhibites the activity of basal-Ca2 -Mg2 -ATPase,Na -K -ATPase and Mg2 -ATPase at the different degree.In addition to CaM,unsaturated fatty acids and limited proteolysis with trypsin can also activate the Ca2 -Mg2 -ATPase.All these activation are inhibited by Tet in a similar cncentra-tion range.This fact suggests that in addition to CaM Tet may bind to membrane Ca2 -Mg2 -ATPase.Addition of Tet may also provide some protection against osmotic lysis of red blood cells.This function reflects that the inhibition of CaM function may be related to drug-induced membrane stabilization.