title: 2-Acylamido analogues of N-acetylglucosamine prime formation of chitin oligosaccharides by yeast chitin synthase 2.
abstract: Chitin, a homopolymer of β1,4-linked N-acetylglucosamine (GlcNAc) residues, is a key component of the cell walls of fungi and the exoskeletons of arthropods. Chitin synthases transfer GlcNAc from UDP-GlcNAc to preexisting chitin chains in reactions that are typically stimulated by free GlcNAc. The effect of GlcNAc was probed by using a yeast strain expressing a single chitin synthase, Chs2, by examining formation of chitin oligosaccharides (COs) and insoluble chitin, and by replacing GlcNAc with 2-acylamido analogues of GlcNAc. Synthesis of COs was strongly dependent on inclusion of GlcNAc in chitin synthase incubations, and N,N'-diacetylchitobiose (GlcNAc2) was the major reaction product. Formation of both COs and insoluble chitin was also stimulated by GlcNAc2 and by N-propanoyl-, N-butanoyl-, and N-glycolylglucosamine. MALDI analyses of the COs made in the presence of 2-acylamido analogues of GlcNAc showed they that contained a single GlcNAc analogue and one or more additional GlcNAc residues. These results indicate that Chs2 can use certain 2-acylamido analogues of GlcNAc, and likely free GlcNAc and GlcNAc2 as well, as GlcNAc acceptors in a UDP-GlcNAc-dependent glycosyltransfer reaction. Further, formation of modified disaccharides indicates that CSs can transfer single GlcNAc residues.
authors.affiliation: From the Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801.
authors.forename: Jacob
authors.initials: J
authors.lastname: Gyore
authors.forename: Archana R
authors.initials: AR
authors.lastname: Parameswar
authors.forename: Carleigh F F
authors.initials: CF
authors.lastname: Hebbard
authors.forename: Younghoon
authors.initials: Y
authors.lastname: Oh
authors.forename: Erfei
authors.initials: E
authors.lastname: Bi
authors.forename: Alexei V
authors.initials: AV
authors.lastname: Demchenko
authors.forename: Neil P
authors.initials: NP
authors.lastname: Price
authors.forename: Peter
authors.initials: P
authors.lastname: Orlean
mesh_terms: D000117:Acetylglucosamine / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D002462:Cell Membrane / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D002686:Chitin / Q000096:biosynthesis* / Q000737:chemistry; D002687:Chitin Synthase / Q000235:genetics / Q000378:metabolism*; D004187:Disaccharides / Q000737:chemistry / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005947:Glucose / Q000494:pharmacology; D009154:Mutation; D009844:Oligosaccharides / Q000096:biosynthesis* / Q000737:chemistry; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D004187:Disaccharides; D009844:Oligosaccharides; D029701:Saccharomyces cerevisiae Proteins; D002686:Chitin; C010913:N,N-diacetylchitobiose; D002687:Chitin Synthase; C582195:Chs2 protein, S cerevisiae; D005947:Glucose; D000117:Acetylglucosamine
keywords: Carbohydrate Biosynthesis; Chitin; Glycosyltransferases; Polysaccharide; Yeast Physiology