Missiaen L, Wuytack F, De Smedt H, Amant F, Casteels R
Department of Physiology, Catholic University of Leuven, Belgium.
Biochem J. 1989 Jul 15;261(2):655-60. doi: 10.1042/bj2610655.
AIF4- inhibits the (Ca2+ + Mg2+)-ATPase activity of the plasma-membrane and the sarcoplasmic-reticulum Ca2+-transport ATPase [Missiaen, Wuytack, De Smedt, Vrolix & Casteels (1988) Biochem. J. 253, 827-833]. The aim of the present work was to investigate this inhibition further. We now report that AIF4- inhibits not only the (Ca2+ + Mg2+)-ATPase activity, but also the ATP-dependent 45Ca2+ transport, and the formation of the phosphoprotein intermediate by these pumps. Mg2+ potentiated the effect of AIF4-, whereas K+ had no such effect. The plasma-membrane Ca2+-transport ATPase from erythrocytes was 20 times less sensitive to inhibition by AIF4- as compared with the Ca2+-transport ATPase from smooth muscle. The endoplasmic-reticulum Ca2+-transport ATPase from smooth muscle was inhibited to a greater extent than the sarcoplasmic-reticulum Ca2+-transport ATPase of slow and fast skeletal muscle.
AlF₄⁻抑制质膜和肌浆网Ca²⁺转运ATP酶的（Ca²⁺ + Mg²⁺）-ATP酶活性[米西亚恩、维塔克、德·斯梅特、弗罗利克斯和卡斯特尔斯（1988年）《生物化学杂志》253卷，827 - 833页]。本研究的目的是进一步探究这种抑制作用。我们现在报告，AlF₄⁻不仅抑制（Ca²⁺ + Mg²⁺）-ATP酶活性，还抑制ATP依赖的⁴⁵Ca²⁺转运以及这些泵形成磷蛋白中间体。Mg²⁺增强了AlF₄⁻的作用，而K⁺则没有这种作用。与平滑肌的Ca²⁺转运ATP酶相比，红细胞质膜Ca²⁺转运ATP酶对AlF₄⁻抑制的敏感性低20倍。平滑肌内质网Ca²⁺转运ATP酶受到的抑制程度大于慢肌和快肌骨骼肌的肌浆网Ca²⁺转运ATP酶。
