溶剂极性对碳酸酐酶热变性的影响

以差示扫描量热技术为手段研究了具不同碳氢链长度及不同浓度的醇－水溶剂对碳酸酐酶热变性温度及热变性焓的影响，以探讨两性分子对蛋白质构象及热稳定性的影响。结果表明，随着甲醇、乙醇及丙醇各自浓度的增加碳酸酐酶的变性温度降低；在相同的醇浓度下随着醇的碳氢链的加长，碳酸酐酶的变性温度明显下降；当醇在低浓度，例如１０％时，碳酸酐酶的热变性焓比在纯缓冲液中要高。而在高浓度时其变性焓比在纯缓冲液中要低，且随着碳氢

THE EFFECT OF COLVENT POLARITY ON THERMODENATURATION OF CARBONIC ANHYDRASE

The effect of aqueous solution of alcohol with different length of hydrocarbon chain andconcentration on denaturation temperature and denaturation enthalpy of carbonic anhydrase was studied by differential scanning calorimetry, The results showed that the denaturationtemperature of carbonic anhydrase decreased as the concentration of methanol, ethanol andn-propyl alcohol increased respectively: the denaturation temperature decreased obviously asthe length of hydrocarbon chain of alcohol increased, the denaturation enthalpy of carbonicanhydiase in alcohol solution of lower concentration such as 10% was higher than that inpare buffer solution, but the denaturation enthalpy of carbonic anhydrase in alcohol solutionof higher concentration was lower than that in pare buffer solution and it decreased obviouslyas the length of hydrocarbon chain and the concentration of alcohol increased.