Stuart J, Abramson J J
Department of Chemistry, Portland State University, Oregon 97207.
Arch Biochem Biophys. 1988 Jul;264(1):125-34. doi: 10.1016/0003-9861(88)90577-2.
Micromolar concentrations of copper (Cu2+) and cysteine induce rapid efflux of calcium from sarcoplasmic reticulum (SR) vesicles. This effect appears to be due to a Cu2+-catalyzed oxidation of the added cysteine to a critical sulfhydryl group on the release protein from sarcoplasmic reticulum (J. L. Trimm, G. Salama, and J. J. Abramson (1986) J. Biol. Chem. 261, 16092-16098). The data presented here indicate that adenine nucleotides synergistically stimulate copper/cysteine (oxidation)-induced calcium efflux from SR vesicles. The order of effectiveness in stimulating calcium efflux is ATP greater than AMP-PCP greater than cAMP greater than AMP greater than adenine approximately NAD approximately NADH. Non-adenine-containing nucleotides such as GTP, CTP, UTP, and ITP and the high energy phosphate compound, acetyl phosphate, were ineffective in stimulating oxidation-induced calcium efflux. The relative effectiveness of various adenine nucleotides in stimulating calcium-induced calcium efflux and oxidation-induced calcium efflux are identical, suggesting that a common mode of action is involved when calcium release is triggered by either method. The stimulatory effect of the adenine nucleotides on oxidation-induced efflux is independent of external magnesium concentration and independent of the magnesium gradient across the SR membrane.
微摩尔浓度的铜离子（Cu2+）和半胱氨酸可诱导肌浆网（SR）囊泡中的钙快速流出。这种效应似乎是由于Cu2+催化添加的半胱氨酸氧化为肌浆网释放蛋白上的关键巯基（J. L. 特里姆、G. 萨拉马和J. J. 艾布拉姆森（1986年）《生物化学杂志》261卷，16092 - 16098页）。此处呈现的数据表明，腺嘌呤核苷酸协同刺激铜/半胱氨酸（氧化）诱导的肌浆网囊泡钙流出。刺激钙流出的有效性顺序为ATP大于AMP - PCP大于cAMP大于AMP大于腺嘌呤约等于NAD约等于NADH。不含腺嘌呤的核苷酸如GTP、CTP、UTP和ITP以及高能磷酸化合物乙酰磷酸在刺激氧化诱导的钙流出方面无效。各种腺嘌呤核苷酸在刺激钙诱导的钙流出和氧化诱导的钙流出方面的相对有效性相同，这表明当通过任何一种方法触发钙释放时涉及共同的作用模式。腺嘌呤核苷酸对氧化诱导流出的刺激作用与外部镁浓度无关，也与跨肌浆网膜的镁梯度无关。
