title: A fluorescence study of isofagomine protonation in β-glucosidase.
abstract: N-(10-Chloro-9-anthracenemethyl)isofagomine 5 and N-(10-chloro-9-anthracenemethyl)-1-deoxynojirimycin 6 were prepared, and their inhibition of almond β-glucosidase was measured. The isofagomine derivative 5 was found to be a potent inhibitor, while the 1-deoxynojirimycin derivative 6 displayed no inhibition at the concentrations investigated. Fluorescence spectroscopy of 5 with almond β-glucosidase at different pH values showed that the inhibitor nitrogen is not protonated when bound to the enzyme. Analysis of pH inhibition data confirmed that 5 binds as the amine to the enzyme's unprotonated dicarboxylate form. This is a radically different binding mode than has been observed with isofagomine and other iminosugars in the literature.
authors.affiliation: Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark. bols@chem.ku.dk.
authors.forename: Emil
authors.initials: E
authors.lastname: Lindbäck
authors.forename: Bo Wegge
authors.initials: BW
authors.lastname: Laursen
authors.forename: Jens Christian Navarro
authors.initials: JC
authors.lastname: Poulsen
authors.forename: Kristine
authors.initials: K
authors.lastname: Kilså
authors.forename: Christian Marcus
authors.initials: CM
authors.lastname: Pedersen
authors.forename: Mikael
authors.initials: M
authors.lastname: Bols
mesh_terms: D060326:Chemistry Techniques, Synthetic; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*; D005944:Glucosamine / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D050112:Imino Pyranoses / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D007700:Kinetics; D011522:Protons; D000068181:Prunus dulcis / Q000201:enzymology; D013050:Spectrometry, Fluorescence; D013329:Structure-Activity Relationship; D001617:beta-Glucosidase / Q000037:antagonists & inhibitors* / Q000378:metabolism
chemical_list: C478924:1-deoxy-nojirimycin; D004791:Enzyme Inhibitors; D050112:Imino Pyranoses; C000605891:N-(10-chloro-9-anthracenemethyl)1-deoxynojirimycin; C000605890:N-(10-chloro-9-anthracenemethyl)isofagomine; D011522:Protons; C098432:isofagomine; D001617:beta-Glucosidase; D005944:Glucosamine