Siegel D P, Ware B R, Green D J, Westhead E W
Biophys J. 1978 May;22(2):341-6. doi: 10.1016/S0006-3495(78)85492-7.
Electrophoretic light scattering was used to determine the electrophoretic mobility distributions of isolated bovine adrenal chromaffin granules as a function of divalent metal ion concentrations. Changes in the electrophoretic mobility reflected changes in the surface charge density of the granules. Ca2+ and Mg2+ (0.10--2.0 mM) were equally effective in reducing the electrophoretic mobilities. These findings are consistent with recent studies of the binding of Ca2+ and Mg2+ to the surface of chromaffin granules and are further evidence that the specific role of Ca2+ in exocytosis is due to effects other than the ability of Ca2+ to decrease the electrostatic repulsion between negatively charged membranes.
采用电泳光散射法测定了分离的牛肾上腺嗜铬颗粒的电泳迁移率分布随二价金属离子浓度的变化情况。电泳迁移率的变化反映了颗粒表面电荷密度的变化。Ca2+和Mg2+(0.10 - 2.0 mM)在降低电泳迁移率方面效果相同。这些发现与最近关于Ca2+和Mg2+与嗜铬颗粒表面结合的研究一致,进一步证明Ca2+在胞吐作用中的特定作用是由于除了Ca2+降低带负电膜之间静电排斥能力之外的其他效应。