Two soluble forms of glutamate dehydrogenase isoproteins from bovine brain.
Two soluble forms of novel glutamate dehydrogenase isoproteins, designated GDH I and GDH II, have been purified from bovine brain. GDH I and GDH II were separated on a hydroxyapatite column and eluted by a step gradient at different phosphate concentrations (30 mM and 50 mM for GDH I and GDH II, respectively). The preparations were homogeneous on SDS/PAGE. GDH I and GDH II showed similarity in their molecular sizes and are composed of six identical subunits having a molecular size of 57,500 Da. Differences between the biochemical properties of GDH I and GDH II, such as N-terminal amino acid sequences of intact and tryptic-digested enzymes, kinetic parameters, optimum pH and heat stability, were extensively examined in both reductive amination of alpha-oxoglutarate and oxidative deamination of glutamate. The different effects of ADP on GDH isoproteins were also studied under various conditions. These results indicate that GDH I and GDH II, isolated from bovine brain, are novel and distinct polypeptides.
Cho
S W
SW
Department of Biochemistry, College of Medicine, University of Ulsan, Seoul, Korea.
Lee
J
J
Choi
S Y
SY
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000201:enzymology*; D002417:Cattle; D005969:Glutamate Dehydrogenase / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D007527:Isoenzymes / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D007700:Kinetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid; D012995:Solubility
D007527:Isoenzymes; D000244:Adenosine Diphosphate; D005969:Glutamate Dehydrogenase