文摘
物理化学的研究Molybednum (VI)淀粉酶交互
作者(年代):r·p·辛格和r·乔杜里研究了钼酸盐离子的绑定b-amylase用极谱法和equilibirum透析技术。绑定的范围已由斯坦福的方法和平均缔合常数的值(日志K)和最大数量的结合位点(n)计算了从Scatchard情节pH值5.57。这些发现是3.3600和17日分别。非线性情节极谱和平衡透析在pH值为5.57分析中小学网站以及他们明显协会常数。他们发现了对数K1和K2从极谱3.9884和2.9348和4.0355和3.2907平衡透析,分别。主(n1)的数量和二级(n2)网站已经发现4和13日分别。单一的参与主要网站也被证实从莫(VI)的吸收光谱;淀粉酶混合物,显示吸收峰在pH值为5.57,而不是在其他高pH值。在更高的pH值范围,极谱不适用,所以莫(VI)绑定到b-amylase是由透析平衡方法在高pH值范围内。这些发现是3.4070,2.2788,2.7980,2.7568和17日16日14日7在pH值为5.57,7.50,9.50和11.50,分别。A good correspondence among the data obtained from the two techniques supported that electrostatic effects are negligible and the alterations of binding constants is solely due to molybdate ion- -amylase combination. The number of sites available for binding with molybdate ions is much less than the actual number of cationic groups on -amylase molecule. The qualitative binding results of pHmetry and spectroscopy are also strongly support the results of diffusion current and dialysis methods. The pH dependence of Mo (VI) - ; - amylase interaction could be explained by assuming an interaction with the positively charged groups such as -ammonium, imidazolium and guanidinium groups, which are ionized at different pH levels. The involvement of fewer such groups in binding processing may be due to the in availability of all cationic groups due to folded structure of ;-amylase molecule. However, owing to the complexity of the macromolecular structure, it was difficult to predict the nature of exact groups that were involved in the molybdate ;- amylase interaction. The free energies of molybdenum (VI) - ; - amylase complexes were also determined for the support of binding of Mo (VI) with -amylase.
