Haiech J, Klee C B, Demaille J G
Biochemistry. 1981 Jun 23;20(13):3890-7. doi: 10.1021/bi00516a035.
The acid stability of calmodulin has been 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 calmodulin has allowed determination of the intrinsic binding constants of each of the three cations for the four 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 be B, A, C, and D. The ordered binding properties support the suggestion that calmodulin translates quantitative Ca2+ signals into qualitatively different cellular responses.
钙调蛋白的酸稳定性已被用于设计一种基于三氯乙酸沉淀的快速高效脱钙方法。对K⁺、Mg²⁺和Ca²⁺与钙调蛋白的Ca²⁺结合位点的竞争性结合研究，使得能够确定这三种阳离子中每种与四个Ca²⁺结合位点的内在结合常数。这些数据与Ca²⁺的有序结合相一致。如果从NH₂末端开始将Ca²⁺位点标记为A、B、C和D，则推测结合顺序为B、A、C和D。这种有序结合特性支持了钙调蛋白将定量的Ca²⁺信号转化为性质不同的细胞反应的观点。
