EFFECTS OF CATIONS ON AFFINITY OF CALMODULIN FOR CALCIUM - ORDERED BINDING OF CALCIUM-IONS ALLOWS THE SPECIFIC ACTIVATION OF CALMODULIN-STIMULATED ENZYMES
EFFECTS OF CATIONS ON AFFINITY OF CALMODULIN FOR CALCIUM - ORDERED BINDING OF CALCIUM-IONS ALLOWS THE SPECIFIC ACTIVATION OF CALMODULIN-STIMULATED ENZYMES
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DOI：
10.1021/bi00516a035
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发表时间：
1981-01-01
期刊：
影响因子：
2.9
通讯作者：
DEMAILLE, JG
中科院分区：
文献类型：
--
作者：
HAIECH, J;KLEE, CB;DEMAILLE, JG
利用钙调蛋白的酸性稳定性，设计了一种快速高效的三氯乙酸法脱钙方法。通过研究K+、Mg~(2+)和Ca~(2+)与钙调素钙离子结合部位的竞争结合，可以确定3种阳离子与4种钙离子结合部位的固有结合常数。数据与钙离子的有序结合是兼容的。如果钙离子从NH2末端开始标记为A、B、C和D，则结合的顺序假定为B、A、C和D。有序的结合特性支持这样的假设，即钙调蛋白将定量的钙信号翻译成定性不同的细胞反应。
The acid stability of calmodulin was used to devise a rapid and efficient method of decalcification based on trichloroacetic acid precipitation. Study of the competitive binding of K+, Mg2+ and Ca2+ to the Ca2+-binding sites of [ram testes] calmodulin allowed determination of the intrinsic binding constants of each of the 3 cations for the 4 Ca2+-binding sites. The data are compatible with an ordered binding of Ca2+. If the Ca2+ sites are labeled A, B, C and D starting at the NH2 terminus, the order of binding is postulated to the B, A, C and D. The ordered binding properties support the suggestion that calmodulin translates quantitative Ca2+ signals into qualitatively different cellular responses.