α-胰凝乳蛋白酶离子基团的离解常数的计算

Calculation of Dissociation Constant of Ionogenic Group in α-Chytrysin

研究了当离子基团从水中转至蛋白球中时,离解常数改变的测定.借助两种溶剂—N,N—二甲基甲(DMF)酰胺和甲酰胺(FA)模拟了近程相互作用的能量变化.考虑到处于蛋白球中的离子与它们周围的电解质溶液的相互作用,研究了Bornian溶剂化能的变化.由于在酶分子中存在内球静电场,研究了离子化能的变化.以上的每项效应对Asp-102-CO2-的能量都有较大的贡献,且相互补偿.

Factors determining the change of dissociation constants of ionogenic group into a protein globule from water are researched. The change of the short range interaction is simulated with the aid of two model solvents： dimethylformamide （DMF） and formamide （FA）. The change of Bornian solvation energy is studied with consideration to the interaction of ions inside a protein globule with the surrounding electrolyte solution. The change of ion energy due to the intraglobular electric field preexisting in the enzyme molecule is also investigated. Each of the factors listed above gives a considerable contribution to the ion energy in the case of Asp - 102, and they compensate each other to a great extent.