Purification and characterization of glutamate dehydrogenase from eel liver

Glutamate dehydrogenase (EC 1.4.1.2-4) has been purified from the acetone powder of eel (Anguilla japonica ) liver; the process utilized affinity chromatography with GTP-Sepharose in the final step. The homogeneity of the enzyme was proved by 1) a single protein-staining band in polyacrylamide gels, 2) a single symmetrical Schlieren peak in the ultracentrifuge, and 3) constant specific activity in the chromatogram obtained by GTP-Sepharose column. Sedimentation analysis gave a S degree sub(2)0,wv)alue of 12.3. The enzyme had a molecular weight of 315,000. In gel electrophoresis, the enzyme showed little mobility if ADP was not added in sample, spacer and separate gel. Amino acid analysis showed that the ratio of quantities of arginine, lysine, and tyrosine to the total residues of amino acids in the eel enzyme were rather higher than those in bovine, rat, and tuna enzymes.