摘要
比较了热变性时大熊猫肌酸激酶的构象与活性的变化，结果表明：酶在４０℃ 及 ４０℃以下温度保温 １０ ｍｉｎ，酶的活性及构象均无明显改变； ４０℃以上酶的活性及构 象发生改变，在４５～５５℃之间，酶的活性与构象发生急剧变化，５５℃时酶活性已完全 丧失，用ＣＤ、荧光及表面流基暴露等手段监测的酶分子的构象也发生很大变化，但尚未 完全，随温度的上升继续发生变化。上述结果表明：酶活性部位的微区构象比较脆弱或 比较柔性，并且酶分子的空间结构是酶具有的活性的基础。
The comparison of conformation and activity changes of enzyme molecule is an important method for studying the relationship between the structure and function of the enzyme.A comparison of conformation and activity changes of creatine kinase from panda during thermal denaturation was studied.No changes of conformation and activity were observed when the enzyme was treated for 10 min at 40℃ or lower.With the temperature increasing,the changes of conformation and activity of enzyme increased,and both the changes sharply increased between 45 and 55℃. The activity of enzyme was completely lost at 55℃. The relative content of reactive SH groups of enzyme increased from 26.1% (native state)to 92. 6% (denatured state) .The activity changes of enzyme were more serious than its conformation changes measured in CD and fluorescence as well as exposed SH groups under the same denaturation conditions.It can be suggested that the conformation of active site of enzyme is more flexible than that of the other site of enzyme, the conformational integrity of enzyme molecule is important for its activity.
出处
《清华大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
1990年第3期75-80,共6页
Journal of Tsinghua University(Science and Technology)
关键词
大熊猫
肌酸激酶
热变性
构象
活性
panda,creatine kinase, thermal denaturation , conformation, activity
