四氢嘧啶对热变性凝乳酶复性作用的研究

目的]加深对部分失活的凝乳酶复性作用的了解,为热稳定性研究中部分失活态凝乳酶的制备提供参考。方法]研究了四氢嘧啶存在的条件下,复性时间、热处理时间和热处理温度等因素对凝乳酶复性作用的影响。结果]随着复性时间的延长,凝乳酶的活力逐渐上升。凝乳酶的复性主要发生在前24 h,36 h后凝乳酶活力基本保持稳定,复性后凝乳酶相对酶活力最高可提升21.8百分点,能够测到凝乳酶活力(相对酶活力损失93.3%)的热处理时间,从6 min延长到12 min。在酶活力损失相近时,含四氢嘧啶的凝乳酶在较高温度下(68~70℃)保温较短时间(1~5 min),复性所致的相对酶活力提升显著高于在较低温度下(61~65℃)长时间保温(30~180 min)。结论]酶的热失活处理的温度和时间对酶分子结构的影响效应并不相同,较长时间的热失活处理比短时高温对酶结构的破坏更彻底。

Study on the Effect of Ectoine on the Renaturation of Thermo-Denatured Rennin

Objective] To deepen the understanding of the refolding of partially inactivated rennet,and to provide reference for the preparation of partially inactivated rennet in the study of thermostability.Method] Effects of renaturation time,heat treatment time and temperature on the renaturation of rennin with ectoine were studied.Result]With the extension of renaturation time,the activity of rennet increased gradually.The ranaturation mainly occurred during the first 24 h.The activity of rennin increased with renaturation time,and kept stable after 36 h.At that time,the relative activity increased 21.8％,and the activity could be measured after longer time of heat treatment (from 6 min to 12 min).Rennin with ectione might loss same activity after incubated at higher temperatures (68-70 ℃) for shorter time (1-5 min) or at lower temperatures (61-65 ℃) for longer time (30-180 min).However,the activity increase by ranaturation of the former was obviously higher than that of the latter.Conclusion] It indicated that the effects of temperature and incubating time of the heat treantment on rennin were different.Longer incubating time might show stronger effects on the structure of rennin molecular.