摘要
纯化的牛心线粒体F1ATP酶(F_1)在有1mol/LKCl的介质中,0℃保温1h,酶活性降到接近于零,经脱盐并在室温(20—25℃)保温,可恢复约60%的酶活性。电泳结果表明,冷盐处理1h的样品解来成了四个亚部分,这四个部分的亚基组成分别是Ⅰ,α,γ,δ,ε,Ⅱ,β,δ,ε,Ⅲ,β,ε,Ⅳ,β。经冷盐处理1h和5h的F_1进行HPLC分析的结果有显著的差别。
The activity of F_1-ATPase (F_1) of beef heart mitochondria decreased very rapidly in the medium of 50mM of Tris , ZmM of EDTA,2mM of ATP and 1M of KCl(pH7. 4), at 0─4℃. In the condition as above for one hour, the activity of F_1 decreased to about zero, accompanied by dissociation of F_1 into four subfractions, as confirmed by polyacrylamide gel electrophoresis analysis at 0℃. The subunit composition of the four parts was Ⅰ ,α、γ、δ、ε; Ⅱ ,β、δ、ε;Ⅲ ,β、ε;Ⅳ,β,according to SDS-electrophoresis analysis. The subfractions of F_1 induced by cold treatment in the presence of 1M of KCl were unstable. If the dissociated condition was removed in time, the activity of F_1 could be partially recovered and the structure restored also. If F_1 was in the dissociated condition for five hrs. some subfractions would combine to a large structure , but the activity of F_1 and the structure of it could not be recovered.These results provided that treated F_1 at 0℃ in the presence of iM of KCl would be a good way for preparing the β subunit and the other subunits, which remained the reconstituted property.It also demonstrated that the dissociated process was a dynamic process.