Groeneveld C M, Canters G W
Eur J Biochem. 1985 Dec 16;153(3):559-64. doi: 10.1111/j.1432-1033.1985.tb09337.x.
The electron self-exchange rate of azurin from Pseudomonas aeruginosa has been measured by proton NMR as a function of temperature under various conditions of pH, buffer and ionic strength. The rate does not appear very sensitive to variations in the latter parameters. Qualitative thermodynamic compensation is observed for the entropy and enthalpy of activation, with a compensation temperature of 309 +/- 7 K, and an average exchange rate of 1.3 X 10(6) M-1 s-1. The observed high entropy of activation contributes significantly to the high exchange rate. The data are analyzed by considering an encounter complex in which two azurin molecules associate along their hydrophobic patches. Copper-to-copper electron transfer over a distance of 1.5 nm in the complex is facilitated by the favourable disposition of the His-117 ligands.
在不同pH值、缓冲液和离子强度条件下，通过质子核磁共振测定了铜绿假单胞菌中蓝铜蛋白的电子自交换速率随温度的变化。该速率对后几个参数的变化似乎不太敏感。观察到活化熵和活化焓存在定性的热力学补偿，补偿温度为309±7 K，平均交换速率为1.3×10⁶ M⁻¹ s⁻¹。观察到的高活化熵对高交换速率有显著贡献。通过考虑一个相遇复合物来分析数据，在该复合物中两个蓝铜蛋白分子沿其疏水区域缔合。复合物中两个铜原子之间1.5纳米距离的电子转移因His-117配体的有利排列而得以促进。
