title: Chemical modification of arginine alleviates the decline in activity during catalysis of spinach Rubisco.
abstract: Arginine residues of spinach ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) were chemically modified with phenylglyoxal (PhG). PhG inactivated Rubisco with a half-time of 20-25 min. An inclusion of a catalytic product, 3-phosphoglycerate (PGA), protected Rubisco from inactivation and delayed the half-time to 60-90 min. Peptide mapping and sequencing of Rubisco modified for 60 min with radiolabeled PhG in the presence of 10mM PGA revealed that Arg187, Arg258, and Arg431 of the large subunit were modified. The extent and rate of the decline in activity during catalysis (fallover phenomenon) were reduced by the modification. This is the first report identifying PhG-modified arginine residues and to demonstrate the effect of the modification of arginine residues on the kinetics of fallover.
authors.affiliation: Department of Materials Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan.
authors.forename: Eiichi
authors.initials: E
authors.lastname: Mizohata
authors.forename: M
authors.initials: M
authors.lastname: Anwaruzzaman
authors.forename: Hiromi
authors.initials: H
authors.lastname: Okuno
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Tomizawa
authors.forename: Shigeru
authors.initials: S
authors.lastname: Shigeoka
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Kai
authors.forename: Akiho
authors.initials: A
authors.lastname: Yokota
mesh_terms: D000595:Amino Acid Sequence; D001120:Arginine / Q000737:chemistry*; D007202:Indicators and Reagents / Q000378:metabolism; D008958:Models, Molecular; D015394:Molecular Structure; D009097:Multienzyme Complexes; D010449:Peptide Mapping; D010658:Phenylglyoxal / Q000378:metabolism; D011487:Protein Conformation; D012273:Ribulose-Bisphosphate Carboxylase / Q000737:chemistry* / Q000378:metabolism*; D018724:Spinacia oleracea / Q000737:chemistry / Q000201:enzymology*
chemical_list: D007202:Indicators and Reagents; D009097:Multienzyme Complexes; D001120:Arginine; D012273:Ribulose-Bisphosphate Carboxylase; D010658:Phenylglyoxal