title: Inactivation of a beta-glucosidase from Arthrobotrys conoides by diethyl pyrocarbonate: evidence of histidine at the active site.
abstract: Modification of A. conoides beta-glucosidase by diethylpyrocarbonate caused rapid inactivation of the enzyme. The kinetic analyses showed that the inactivation by diethylpyrocarbonate resulted from the modification of an average of one histidine residue per mole of enzyme. The modified enzyme showed an increase in absorbance at 240 nm. Sulphydryl, lysine and tyrosine residues were not modified by diethylpyrocarbonate treatment. The substrate offered significant protection against diethylpyrocarbonates modification. The results indicate that diethylpyrocarbonate was interacting with the enzyme at or near the active site.
authors.affiliation: Department of Biochemistry, Wilson College, Bombay, India.
authors.forename: K D
authors.initials: KD
authors.lastname: Kumble
authors.forename: S
authors.initials: S
authors.lastname: Kumble
authors.forename: M B
authors.initials: MB
authors.lastname: Jaffar
mesh_terms: D001665:Binding Sites; D004047:Diethyl Pyrocarbonate / Q000494:pharmacology*; D006639:Histidine / Q000502:physiology*; D007460:Iodoacetamide / Q000494:pharmacology; D003904:Mitosporic Fungi / Q000201:enzymology; D009598:Nitrophenylgalactosides / Q000494:pharmacology; D011732:Pyridoxal Phosphate / Q000494:pharmacology; D001617:beta-Glucosidase / Q000187:drug effects* / Q000302:isolation & purification
chemical_list: D009598:Nitrophenylgalactosides; C059200:4-nitrophenylgalactoside; D006639:Histidine; D011732:Pyridoxal Phosphate; D001617:beta-Glucosidase; D004047:Diethyl Pyrocarbonate; D007460:Iodoacetamide