title: The inactivation of beta-galactosidase (E. coli) by the carbodiimide reaction.
abstract: When beta-galactosidase reacted with 1-ethyl-3(3-dimethylaminopropyl)-carbodiimide (EDC), activity was lost. The inhibitor, isopropyl-beta-D-galactopyranoside (IPTG), decreased inactivation. Of 3 nucleophiles tested, incorporation was only decreased in the protected (IPTG added) enzyme when sulfanilic acid was the nucleophile but HPLC profiles of tryptic peptides were identical in protected and unprotected enzyme (except for magnitude). There were also no differences (except for magnitude) of HPLC profiles after 10 and 90 min of reaction and between active (soluble) and inactive (precipitated) enzyme. The data indicate that inactivation is not caused by reaction with a specific active site group. Inactivation probably occurs when a combination of groups are reacted.
mesh_terms: D001665:Binding Sites; D001667:Binding, Competitive; D002234:Carbodiimides / Q000494:pharmacology*; D011232:Chemical Precipitation; D002851:Chromatography, High Pressure Liquid; D004789:Enzyme Activation / Q000187:drug effects; D004926:Escherichia coli / Q000201:enzymology*; D019856:Ethanolamine; D004983:Ethanolamines / Q000378:metabolism; D005022:Ethyldimethylaminopropyl Carbodiimide / Q000494:pharmacology*; D005688:Galactosamine / Q000378:metabolism; D005696:Galactosidases / Q000037:antagonists & inhibitors*; D007544:Isopropyl Thiogalactoside / Q000494:pharmacology*; D007700:Kinetics; D010446:Peptide Fragments / Q000302:isolation & purification / Q000378:metabolism; D013425:Sulfanilic Acids / Q000378:metabolism; D013865:Thioglycosides / Q000494:pharmacology*; D014357:Trypsin; D001616:beta-Galactosidase / Q000037:antagonists & inhibitors* / Q000378:metabolism
chemical_list: D002234:Carbodiimides; D004983:Ethanolamines; D010446:Peptide Fragments; D013425:Sulfanilic Acids; D013865:Thioglycosides; D007544:Isopropyl Thiogalactoside; D019856:Ethanolamine; D005688:Galactosamine; D005696:Galactosidases; D001616:beta-Galactosidase; D014357:Trypsin; D005022:Ethyldimethylaminopropyl Carbodiimide