期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1980
卷号：77
期号：4
页码：1966-1969
DOI：10.1073/pnas.77.4.1966
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Kinetic analysis of the in vitro reconstitution of glyceraldehyde-3-phosphate dehydrogenase [D-glyceraldehyde-3-phosphate:NAD+ oxidoreductase (phosphorylating), EC 1.2.1.12 ] from yeast showed that both oxidized and reduced coenzyme enhance the transconformation reaction, which is rate limiting in the sequential folding-association process at high enzyme concentrations (Krebs, H., Rudolph, R. & Jaenicke, R. (1979) Eur. J. Biochem. 100, 359-364). In the present study the reconstitution of the enzyme has been analyzed after covalent modification with the coenzyme analog 3-[(3-bromoacetylpyridinio)-propyl]adenosine pyrophosphate. Reconstitution of the modified enzyme, as determined by the regain of the native tryptophan fluorescence, is found to be more then 10 times faster than refolding of the unmodified apoenzyme and more than 5 times faster than that of the unmodified holoenzyme. Various degrees of denaturation and the presence of up to 0.4 M guanidine . HCl do not affect the rate of reconstitution of the modified enzyme. The kinetic effect of free or covalently bound coenzyme is discussed in terms of a decrease in free energy of the native or native-like structure or in terms of a decreased activation energy of rate-limiting steps in the process of reconstitution. Stabilization of the dimeric intermediate or acceleration of its transformation seems to be the most likely explanation for the observed effect of free or covalently bound coenzyme on the rate of reconstitution.
