%0 Journal Article
%T COMPARISON OF THE RATES OF INACTIVATION AND INTRINSIC FLUORESCENCE CHANGES OF LACTATE DEHYDROGENASE H4 DURING GUANIDINE DENATURATION<br>猪心乳酸脱氢酶(H_4)在盐酸胍变性过程中失活与内源荧光变化速度的比较
%A 马永泽
%J 生物物理学报
%D 1991
%I 
%X The rates of inactivation and intrinsic fluorescence changes of lactate dehydrogenase H4 during denaturation by guanidine in the absence or presence of 2M ammonium sulfate have been compared. The course of inactivation consisted of three phases, that is, very fast phase, fast phase and slow phase. The rate of inactivation at very fast phase cannot be measured even with the stopped-flow apparatus. The rate constants of fast and slow phases of inactivation of enzyme denatured in 1M guanidine were 2.7×10-3 sec-1 and 4.17×10-4 sec-1 respectively. In the presence of 2M ammonium sulfate, the rate constants of fast and slow phases of inactivation of enzyme in 2M guanidine were 6.16×10-3 sec-1 and 1.88×10-3 sec-1 respectively. The process of intrinsic fluorescence changs showed two phases, very fast phase and fast phase. The magnitude of intrinsic fluorescence intensity changes was markdly smaller than that of inactivation during very fast phase. The rate constant of intrinsic fluorescencn changes of fast phaes was 1/3 times that of inactivation of fast phase. Thelresults described above indicated that like creatine kinase, the rate of inactivation of lactate dehydrogenase was faster than that of intrinsic fluorescence changes. It is suggested that the active site of lactate dehydrogenase is situated in a limited region of enzyme molecule and its conformational changes are more sensitive to denaturant as compared to the molecule as a whole.
%K 乳酸脱氢酶
%K 盐酸胍变性
%K 失活
%K 荧光
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=90BA3D13E7F3BC869AC96FB3DA594E3FE34FBF7B8BC0E591&jid=E0C9D9BBED813D6674AC13E942EAC86D&aid=5E86E445AE6962DC23EE764D02C40443&yid=116CB34717B0B183&vid=DF92D298D3FF1E6E&iid=38B194292C032A66&sid=F7BB24011DC0D223&eid=F4BDB5452F9F5642&journal_id=1000-6737&journal_name=生物物理学报&referenced_num=0&reference_num=3