Arginyl residues in the NADPH-binding sites of phenol hydroxylase.
Phenol hydroxylase was inactivated by the arginine reagents 2,3-butanedione, 1,2-cyclohexanedione, and phenylglyoxal. The cosubstrate NADPH, as well as NADPH+ and several analogues thereof, protected the enzyme against inactivation. Phenol did not protect the activity against any of the reagents used, nor did modification by 2,3-butanedione affect the binding of phenol. We propose the presence of arginyl residues in the binding sites for the adenosine phosphate part of NADPH.
Sejlitz
T
T
Department of Biochemistry and Biotechnology, Royal Institute of Technology, Stockholm, Sweden.
Neujahr
H Y
HY
D001120:Arginine / Q000032:analysis*; D001665:Binding Sites; D003512:Cyclohexanones / Q000494:pharmacology; D003931:Diacetyl / Q000494:pharmacology; D005453:Fluorescence; D007700:Kinetics; D006899:Mixed Function Oxygenases / Q000737:chemistry*; D009249:NADP / Q000378:metabolism*; D010658:Phenylglyoxal / Q000494:pharmacology
D003512:Cyclohexanones; D009249:NADP; C018031:1,2-cyclohexanedione; D001120:Arginine; D006899:Mixed Function Oxygenases; C022336:phenol 2-monooxygenase; D003931:Diacetyl; D010658:Phenylglyoxal