A study of some of the physical properties of glyceraldehyde-3-phosphate dehydrogenase.

Preparation of Enzyme SolutionsRabbit muscle glyceraldehyde-3-phosphate dehydrogenase was prepared as described previously (1) and stored at 0” as the crystalline suspension. For use, the crystals were separated by centrifugation and dissolved in buffer. The resulting solution was dialyzed overnight against a flowing stream of buffer in order to remove the ammonium sulfate, equilibrated against fresh buffer for 24 hours, and then centrifuged to clarify the solution. Ethylenediaminetetraacetate ion, 0.002 M, was present in all solutions. Sedimentation-The enzyme was sedimented in a Spinco model E ultracentrifuge at 59,780 r.p.m. and the sedimentation constant (s) calculated from the least squares slope of the curve