Purification and separation of pyridine nucleotide-linked dehydrogenases by affinity chromatography techniques

A number of different dehydrogenases have been shown to bind to Sepharose-bound N(6)-(6-aminohexyl)-AMP. These dehydrogenases can be specifically eluted by binary adducts of NAD(+) or with cofactor gradients. In such manner pure enzymes can be obtained from crude extracts, as demonstrated in the purification on a preparative scale of lactate dehydrogenase from dogfish muscle. The data presented indicate the usefulness of general ligands as affinity agents. The techniques are particularly adaptable for the isolation of human mutant enzymes in blood or in the purification and concentration of enzymes present at low levels in fluids or tissues, as shown in the extensive purification of serum lactate dehydrogenase and glucose 6-phosphate dehydrogenase from hemolysate. lsoenzymes with different affinities for co-enzymes can be separated by affinity techniques. Application of affinity techniques may lead to the separation of isoenzymes or mutant enzymes that are not separable by electrophoretic methods.