Kauffman R F, Taylor R W, Pfeiffer D R
J Biol Chem. 1980 Apr 10;255(7):2735-9.
Based on the effects of ionomycin upon mitochondrial respiration, ionomycin was shown to be an effective ionophore for Ca2+ in rat liver mitochondria. The ionomycin-induced efflux of Ca2+ across the inner membrane was more sensitive to loading the mitochondria with Ca2+ than was efflux catalyzed by A23187. At saturating concentrations of Ca2+, the turnover number for ionomycin was 3- to 5-fold greater than that of A23187. Ionomycin catalyzed the efflux of mitochondrial Mg2+ at rates comparable to those observed with A23187. Ionomycin also mediated an efflux of K+ provided that the mitochondria were depleted of their endogenous divalent metal ions. The apparent turnover numbers for K+ efflux suggest that ionomycin is more specific for divalent metal ions than A23187.
基于离子霉素对线粒体呼吸的影响，离子霉素被证明是大鼠肝线粒体中一种有效的钙离子载体。离子霉素诱导的钙离子跨内膜外流对线粒体加载钙离子比A23187催化的外流更敏感。在钙离子饱和浓度下，离子霉素的转换数比A23187高3至5倍。离子霉素催化线粒体镁离子外流的速率与A23187相当。离子霉素还介导钾离子外流，前提是线粒体耗尽其内源性二价金属离子。钾离子外流的表观转换数表明，离子霉素比A23187对二价金属离子更具特异性。
