Adjustment of conformational flexibility of glyceraldehyde-3-phosphate dehydrogenase as a means of thermal adaptation and allosteric regulation
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from Thermotoga maritima (TmGAPDH) is a thermostable enzyme (T m = 102°C), which is fully active at temperatures near 80°C but has very low activity at room temperature. In search for an explanation of this behavior, we measured the conformational flexibility of the protein by hydrogen–deuterium exchange and compared the results with those obtained with GAPDH from rabbit muscle (RmGAPDH). At room temperature, the conformational flexibility of TmGAPDH is much less than that of RmGAPDH, but increases with increasing temperature and becomes comparable to that of RmGAPDH near the physiological temperature of Thermotoga maritima. Using the available three-dimensional structures of the two enzymes, we compared the B factors that reflect the local mobility of protein atoms. The largest differences in B factors are seen in the coenzyme and NAD binding regions. The likely reason for the low activity of TmGAPDH at room temperature is that the motions required for enzyme functions are restricted. The findings support the idea of “corresponding states” which claims that over the time span of evolution, the overall conformational flexibility of proteins has been preserved at their corresponding physiological temperatures.
KeywordsConformational flexibility Thermal adaptation Protein stability Glyceraldehyde-3-phosphate dehydrogenase Allosteric regulation
Péter Závodszky was supported by the Hungarian National Science Foundation (OTKA) Grants T046412, and NI-61915. A.S. was supported by a Bolyai János fellowship.
- Bolotina IA, Vol’kenshtein MV, Zavodszky P, Markovich DS (1966) Polarimetric studies of the conformational changes in d-glyceric aldehyde-3-phosphate dehydrogenase. Biokhimiia 31:649–653Google Scholar
- Demchenko AP (1997) Breaks in Arrhenius plots for enzyme reactions: the switches between different protein dynamics regimes? Comments Mol Cell Biophys 9:87–112Google Scholar
- Hara MR, Agrawal N, Kim SF, Cascio MB, Fujimuro M, Ozeki Y, Takahashi M, Cheah JH, Tankou SK, Hester LD, Ferris CD, Hayward SD, Snyder SH, Sawa A (2005) S-nitrosylated GAPDH initiates apoptotic cell death by nuclear translocation following Siah1 binding. Nat Cell Biol 7:665–674CrossRefGoogle Scholar
- Rehaber V, Jaenicke R (1992) Stability and reconstitution of d-glyceraldehyde-3-phosphate dehydrogenase from the hyperthermophilic eubacterium Thermotoga maritima. J Biol Chem 267:10999–11006Google Scholar
- Zavodszky P, Abaturov LB, Varshavsky YM (1966) Structure of glyceraldehyde-3-phosphate dehydrogenase and its alteration by coenzyme binding. Acta Biochim Biophys Acad Sci Hung 1:389–402Google Scholar