Cryoinactivation and conformational drift of glyceraldehyde-3-phosphate dehydrogenase from rabbit muscle.

The cryoinactivation of glyceraldehyde-3-phosphate dehydrogenase from rabbit muscle (GAPDH-rabbit) was studied. It was found that the inactivation of GAPDH-rabbit at 0 degrees C was much faster than that of GAPDH from yeasts, and showed obvious time and concentration dependence. The spectral properties, enzyme activity and behavior under pressure, of GAPDH-rabbit treated either by cryoinactivation, or pressure-induced dissociation and reassociation, were very similar. These results provided evidence to support the idea that cryoinactivation of oligomeric proteins, might take place through a cycle of dissociation-reassociation accompanied with the so-called conformational drift postulated by King and Weber (1986).