title: Disaccharide analogs as probes for glycosyltransferases in Mycobacterium tuberculosis.
abstract: Glycosyltransferases (GTs) play a crucial role in mycobacterial cell wall biosynthesis and are necessary for the survival of mycobacteria. Hence, these enzymes are potential new drug targets for the treatment of tuberculosis (TB), especially multiple drug-resistant TB (MDR-TB). Herein, we report the efficient syntheses of Araf(alpha 1-->5)Araf, Galf(beta 1-->5)Galf, and Galf(beta 1-->6)Galf disaccharides possessing a 5-N,N-dimethylaminonaphthalene-1-sulfonamidoethyl (dansyl) unit that were prepared as fluorescent disaccharide acceptors for arabinosyl- and galactosyl-transferases, respectively. Such analogs may offer advantages relative to radiolabeled acceptors or donors for studying the enzymes and for assay development and compound screening. Additionally, analogs possessing a 5-azidonaphthalene-1-sulfonamidoethyl unit were prepared as photoaffinity probes for their potential utility in studying active site labeling of the GTs (arabinosyl and galactosyl) in Mycobacterium tuberculosis (MTB). Beyond their preparation, initial biological testing and kinetic analysis of these disaccharides as acceptors toward glycosyltransferases are also presented.
authors.affiliation: Drug Discovery Division, Southern Research Institute, PO Box 55305, Birmingham, AL 35255, USA.
authors.forename: Ashish K
authors.initials: AK
authors.lastname: Pathak
authors.forename: Vibha
authors.initials: V
authors.lastname: Pathak
authors.forename: Lainne
authors.initials: L
authors.lastname: Seitz
authors.forename: Sudagar S
authors.initials: SS
authors.lastname: Gurcha
authors.forename: Gurdyal S
authors.initials: GS
authors.lastname: Besra
authors.forename: James M
authors.initials: JM
authors.lastname: Riordan
authors.forename: Robert C
authors.initials: RC
authors.lastname: Reynolds
mesh_terms: D002384:Catalysis; D004187:Disaccharides / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism*; D005685:Galactans / Q000737:chemistry; D006031:Glycosylation; D016695:Glycosyltransferases / Q000032:analysis* / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009169:Mycobacterium tuberculosis / Q000201:enzymology*; D010084:Oxidation-Reduction; D010777:Photochemistry
chemical_list: D004187:Disaccharides; D005685:Galactans; D016695:Glycosyltransferases; C005653:arabinogalactan