Sulfate-mediated affinity chromatography on NADP+-Sepharose of glutamate dehydrogenase from halophilic bacteria and of glucose-6-phosphate dehydrogenase from Escherichia coli.

An improved synthesis of the 8-(6-aminohexyl)amino derivative of NADP+ is described for use in affinity chromatography. The binding of glutamate dehydrogenase isolated from halobacterium of the Dead Sea on a column of Sepharose linked to this NADP+ derivative could be drastically enhanced by addition of sulfate (1M) and provided a tool for partially purifying the enzyme from a crude extract. A similar finding is reported for glucose-6-phosphate dehydrogenase in crude extracts of Escherichia coli. The effects are shown to be biospecific, suggesting that the strength of the interaction between protein and immobilized coenzymes is a function of the sulfate concentration.