Modification of arginine residues at the substrate binding site of yeast glutathione reductase.
Indian J Biochem Biophys
;
1998 Jun; 35(3): 157-60
Article
in English
| IMSEAR
| ID: sea-26736
ABSTRACT
Yeast glutathione reductase (GR) was inactivated by phenylglyoxal (PG), which specifically modifies arginine residues of the enzyme. Inactivation followed psuedo-first order rate kinetics. There was no reversible complex formation prior to inactivation. Analysis of the kinetic data showed the order of reaction to be unity with respect to the modifier. Inactivation of GR was completely prevented by the presence of oxidised glutathione (GSSG), whereas NADP gave only partial protection. Stoichiometric studies showed that around four arginine residues per subunit were modified by PG in the absence of GSSG, whereas only one was modified in its presence. From these observations, it is concluded that essential arginine residues are present at the substrate binding site.
Full text:
Available
Index:
IMSEAR (South-East Asia)
Main subject:
Phenylglyoxal
/
Arginine
/
Binding Sites
/
Fungal Proteins
/
Kinetics
/
Glutathione Disulfide
/
Enzyme Inhibitors
/
Fungi
/
Glutathione Reductase
/
NADP
Language:
English
Journal:
Indian J Biochem Biophys
Year:
1998
Type:
Article
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