论文部分内容阅读
用差示扫描量热法,在310～450K温度范围、0.048～4.39克水/克干酶以及pH3～9范围内研究了蛋白酶K(EC 3.4.21.14)的热变性。分别提出表征热变性过程的三个主要热力学参数:热变性温度T_d、比变性焓△H_d及超额表观比热C_(ex)~(max)和总水量h以及pH的关系。除Td和h的关系属于Flory-Garrett类型外,蛋白酶K的热变性热力学特征和已报道的球蛋白、双螺旋蛋白及三螺旋蛋白不相同。一级水合水对蛋白酶K热变性热力学特征有最大的影响,pH也是影响该酶热稳定性的重要因素。
Thermal denaturation of proteinase K (EC 3.4.21.14) was studied by differential scanning calorimetry over the temperature range 310-450 K, 0.048-4.49 g water / g dry enzyme, and pH 3-9. The three main thermodynamic parameters that characterize the thermal denaturation processes are presented respectively: the heat denaturation temperature T_d, the relative enthalpy △ H_d and the excess apparent specific heat C_ (ex) ~ max and the total water h and pH. With the exception of the Flory-Garrett type, the thermodynamic properties of Protease K are not the same as those reported for globulin, double helix, and triple helix, except that the relationship between Td and h is of the Flory-Garrett type. The first hydration water has the greatest effect on the thermodynamic properties of proteinase K, and pH is also an important factor affecting the thermostability of the enzyme.