title: A bisubstrate analog inhibitor for alpha(1----2)-fucosyltransferase.
abstract: Porcine submaxillary beta-galactoside alpha(1----2)-fucosyltransferase is known to transfer a fucosyl residue from guanosine 5'-diphosphofucose (GDP-fucose) to the 2-OH group of beta-D-galactopyranosides with inversion of configuration at the fucopyranosyl anomeric carbon. A bisubstrate analog (1) of the postulated transition-state for this reaction, which has O-2 of phenyl beta-D-galactopyranoside attached to the terminal phosphorous of GDP through a flexible ethylene bridge, has been chemically synthesized and evaluated as an inhibitor of this enzyme. Compound 1 was found to be a competitive inhibitor with respect to both GDP-fucose and phenyl beta-D-galactopyranoside for both the membrane-bound and soluble forms of the fucosyltransferase. It was also a competitive inhibitor with respect to the alternate acceptor beta DGal(1----3)beta DGlcNAcO(CH2)8-COOMe. The Ki values were in the range 2.3-16 microM. Compound 1 is the first example of a bisubstrate analog inhibitor for a glycosyltransferase which binds to both the acceptor and donor recognition sites of the enzyme. The potential of a bisubstrate analog strategy for the production of specific glycosyltransferase inhibitors is discussed.
authors.affiliation: Department of Food Science, University of Alberta, Edmonton, Canada.
authors.forename: M M
authors.initials: MM
authors.lastname: Palcic
authors.forename: L D
authors.initials: LD
authors.lastname: Heerze
authors.forename: O P
authors.initials: OP
authors.lastname: Srivastava
authors.forename: O
authors.initials: O
authors.lastname: Hindsgaul
mesh_terms: D000818:Animals; D001665:Binding Sites; D001667:Binding, Competitive; D005647:Fucosyltransferases / Q000037:antagonists & inhibitors*; D005695:Galactosephosphates / Q000378:metabolism / Q000494:pharmacology*; D005697:Galactosides / Q000378:metabolism; D006031:Glycosylation; D006150:Guanine Nucleotides / Q000494:pharmacology*; D006153:Guanosine Diphosphate / Q000378:metabolism; D006154:Guanosine Diphosphate Fucose / Q000378:metabolism; D006157:Guanosine Monophosphate / Q000378:metabolism / Q000494:pharmacology* / Q000031:analogs & derivatives; D006600:Hexosephosphates / Q000494:pharmacology*; D006602:Hexosyltransferases / Q000037:antagonists & inhibitors*; D007700:Kinetics; D015394:Molecular Structure; D011487:Protein Conformation; D013363:Submandibular Gland / Q000201:enzymology; D013552:Swine; D000097631:Galactoside 2-alpha-L-fucosyltransferase
chemical_list: D005647:Fucosyltransferases; D005695:Galactosephosphates; D005697:Galactosides; D006150:Guanine Nucleotides; D006153:Guanosine Diphosphate; D006154:Guanosine Diphosphate Fucose; D006157:Guanosine Monophosphate; D006600:Hexosephosphates; D006602:Hexosyltransferases; D000097631:Galactoside 2-alpha-L-fucosyltransferase; C061372:phenyl 2-O-(2-phosphonoethyl)galactopyranoside guanosine-5'-phosphate anhydride; C046399:phenyl-D-galactopyranoside