Cross-linking and coupling of rabbit muscle aldolase and glyceraldehyde-3-phosphate dehydrogenase by glutaraldehyde.

The mode of cross-linking of rabbit-muscle aldolase and glyceraldehyde-3-phosphate dehydrogenase by glutaraldehyde was studied. The about 5 A long reagent can partly cross-link subunits within the tetramers, whereas it is readily able to make intermolecular cross-links producing polymeric enzyme species. Of the two enzymes, glyceraldehyde-3-phosphate dehydrogenase has a greater tendency to polymerize in the presence of glutaraldehyde. In the case of aldolase, the inter- and intramolecular cross-links between subunits can be distinguished by SDS gel-electrophoresis. The copolymerization pattern of the two enzymes indicates that, though the formation of mixed polyenzymes can be detected by affinity chromatography on human erythrocyte ghosts, under the conditions tested these proteins do not form heterologous enzyme complexes that could be trapped by glutaraldehyde.