title: Reversible alkylation of a methionyl residue near the active site of  -galactosidase.
mesh_terms: D000081:Acetamides; D000085:Acetates; D000478:Alkylation; D000606:Amino Sugars; D000614:Aminocaproates; D001665:Binding Sites; D001966:Bromine; D002247:Carbon Isotopes; D055598:Chemical Phenomena; D002621:Chemistry; D004789:Enzyme Activation; D004926:Escherichia coli / Q000201:enzymology*; D005643:Fucose; D005690:Galactose; D005696:Galactosidases / Q000037:antagonists & inhibitors*; D006207:Half-Life; D006863:Hydrogen-Ion Concentration; D007461:Iodoacetates; D007700:Kinetics; D008623:Mercaptoethanol; D008715:Methionine
chemical_list: D000081:Acetamides; D000085:Acetates; D000606:Amino Sugars; D000614:Aminocaproates; D002247:Carbon Isotopes; D007461:Iodoacetates; D005643:Fucose; D008623:Mercaptoethanol; D008715:Methionine; D005696:Galactosidases; D001966:Bromine; D005690:Galactose