Chemical modification of arginine alleviates the decline in activity during catalysis of spinach Rubisco.
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.
Mizohata
Eiichi
E
Department of Materials Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan.
Anwaruzzaman
M
M
Okuno
Hiromi
H
Tomizawa
Ken-Ichi
K
Shigeoka
Shigeru
S
Kai
Yasushi
Y
Yokota
Akiho
A
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*
D007202:Indicators and Reagents; D009097:Multienzyme Complexes; D001120:Arginine; D012273:Ribulose-Bisphosphate Carboxylase; D010658:Phenylglyoxal