Analytical‐Band Centrifugation of an Active Enzyme Substrate Complex

Through the use of the analytical active‐enzyme‐centrifugation method we have been able to measure the sedimentation coefficients of enzymes which have not yet been obtained in highly purified preparations: aspartate‐semialdehyde dehydrogenase from Escherichia coli and from yeast and lactate dehydrogenase from rabbit muscle. We have also been able to determine unambigously the polymerization state of the fully active unit of β‐galatosidase from E. coli , alcohol dehydrogenase from yeast as well as the polymerization state of the fully active unit of two enzymes which undergo an association‐dissociation concentration‐dependent reaction, glucose‐6‐phosphate dehydrogenase from yeast and glutamate dehydrogenase from beef liver (for this last enzyme the active‐enzyme‐centrifugation method has been applied with NAD, NADH, NADP and NADPH as coenzymes and also for its alanine dehydrogenase activity).