Yazawa M, Kawamura E, Minowa O, Yagi K, Ikura M, Hikichi K
J Biochem. 1984 Feb;95(2):443-6. doi: 10.1093/oxfordjournals.jbchem.a134625.
A single cysteine residue (Cys-27) of wheat calmodulin was labeled with 13C by cyanylation. No change in the Ca2+ saturation pattern was observed after the cyanylation. On titration which Ca2+, the chemical shift of the 13C-label showed a downfield shift. The downfield shift was observed at Ca2+/calmodulin molar ratios between 1.8 and 3.5, while a blue shift of the UV absorption of Tyr-139 was observed between 0 and 1.7. The result indicated the domain 1 containing Cys-27 to be the low affinity site for Ca2+.
通过氰化反应，用(^{13}C)标记了小麦钙调蛋白的单个半胱氨酸残基（Cys-27）。氰化反应后未观察到(Ca^{2+})饱和模式的变化。在用(Ca^{2+})滴定过程中，(^{13}C)标记物的化学位移出现了向低场移动。在(Ca^{2+}/)钙调蛋白摩尔比为(1.8)至(3.5)之间观察到了这种向低场移动，而在(0)至(1.7)之间观察到了Tyr-139的紫外吸收出现蓝移。结果表明含有Cys-27的结构域1是(Ca^{2+})的低亲和力位点。
