首页 | 本学科首页   官方微博 | 高级检索  
     


Once again about the functional coupling between mitochondrial creatine kinase and adenine nucleotide translocase
Authors:Lipskaya T Yu  Savchenko M S
Affiliation:(1) Department of Biochemistry, School of Biology, Lomonosov Moscow State University, Moscow, 119992, Russia
Abstract:The synthesis of creatine phosphate (CP) by mitochondrial creatine kinase during oxidative phosphorylation was terminated when the mass action ratio of the creatine kinase reaction Gamma = [ADP]·[CP][ATP]·[Cr] became equal to the apparent equilibrium constant (Keqapp) of this reaction. Subsequent excess of Gamma over the Keqapp was due to an increase in the ADP concentration in the medium. A comparable increase in the ADP concentration also occurred in the absence of creatine (Cr) in the incubation medium. Increase in the ADP concentration was shown to be associated with a decrease in the rate of oxidative phosphorylation and with a relative increase in the ATPase activity of mitochondria during the incubation. A low concentration of ADP (<30 mgrM) and relatively high concentrations (1-6 mM) of other components of the creatine kinase reaction prevented the detection of the reverse reaction within 10 min after Gamma exceeded the Keqapp, but the reverse reaction became evident on more prolonged incubation. The reverse reaction was accompanied by a further increase in Gamma. Low ADP concentration in the medium was also responsible for the lack of an immediate conversion of the excess creatine phosphate added although Gamma > Keqapp. The findings are concluded to be in contradiction with the concept of microcompartment formation between mitochondrial creatine kinase and adenine nucleotide translocase.
Keywords:mitochondrial creatine kinase  physiological role  adenine nucleotide translocase  functional coupling
本文献已被 PubMed SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号