Modification of alpha-chymotrypsin using a water-soluble photo-Fenton reagent.
Modification of an enzyme, alpha-chymotrypsin, was examined by using a water-soluble photo-Fenton reagent. By photoirradiation of the enzyme with the reagent, which can occupy a binding site of the enzyme, a tryptophan residue in the vicinity of the active site was oxidized to N-formylkynurenine. Concurrently, the catalytic properties of the enzyme were largely changed: the Km was increased and the kcat was decreased. The decrease in kcat for a specific amide substrate was the most significant among the esters and amides examined. The water-soluble photo-Fenton reagent would be useful to chemically modify relatively limited regions in biomolecules.
Kitano
H
H
Department of Chemical and Biochemical Engineering, Toyama University, Japan.
Maeda
Y
Y
Furukawa
K
K
Yamamoto
T
T
Izumida
R
R
Matsugo
S
S
D000818:Animals; D001665:Binding Sites; D002417:Cattle; D002918:Chymotrypsin / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000528:radiation effects; D006861:Hydrogen Peroxide; D066298:In Vitro Techniques; D007202:Indicators and Reagents; D007501:Iron; D007700:Kinetics; D010084:Oxidation-Reduction; D010777:Photochemistry; D012995:Solubility; D014867:Water
C045076:Fenton's reagent; D007202:Indicators and Reagents; D014867:Water; D006861:Hydrogen Peroxide; D007501:Iron; D002918:Chymotrypsin