Identification of essential arginine residue(s) for Mg-ATP binding of human argininosuccinate synthetase.
Human argininosuccinate synthetase (ASS) activity was found to be inactivated by alpha-dicarbonyls such as 1,2-cyclohexanedione and phenylglyoxal in accordance with pseudo first-order kinetics. The enzyme was almost completely protected from this inactivation by Mg-ATP and partially by its analogues. The strongest protective effect against inactivation was found with Mg-ATP, followed by Mg-ADP, AMP, adenosine and Mg-inorganic pyrophosphate. These results suggest the importance of arginine residue(s) for Mg-ATP binding. We determined the amino acid sequence of the peptide with the highest specific radioactivity derived from ASS which had been labeled with [14C]phenylglyoxal and then cleaved by cyanogen bromide treatment. The sequence obtained, PEFYNRFKGRNDLM, corresponds to residues 148-161 of the amino acid sequence deduced from the cDNA nucleotide sequence determined by Bock et al. [Nucleic Acids Res 11:6505-6512, 1983], and has a high homology with the sequences of ATP-binding sites proposed for several ATP-requiring enzymes.
Isashiki
Y
Y
Department of Biochemistry, Faculty of Medicine, Kagoshima University, Japan.
Noda
T
T
Kobayashi
K
K
Sase
M
M
Saheki
T
T
Titani
K
K
D000255:Adenosine Triphosphate / Q000378:metabolism*; D000595:Amino Acid Sequence; D001120:Arginine / Q000378:metabolism*; D001124:Argininosuccinate Synthase / Q000378:metabolism*; D002850:Chromatography, Gel; D003512:Cyclohexanones / Q000494:pharmacology; D004789:Enzyme Activation; D006801:Humans; D007700:Kinetics; D008025:Ligases / Q000378:metabolism*; D008099:Liver / Q000201:enzymology*; D008969:Molecular Sequence Data; D010658:Phenylglyoxal / Q000494:pharmacology; D012689:Sequence Homology, Nucleic Acid
D003512:Cyclohexanones; C018031:1,2-cyclohexanedione; D000255:Adenosine Triphosphate; D001120:Arginine; D008025:Ligases; D001124:Argininosuccinate Synthase; D010658:Phenylglyoxal