title: Synthesis of complex carbohydrates and glyconjugates: enzymatic synthesis of globotetraose using alpha-1,3-N-acetylgalactosaminyltransferase LgtD from Haemophilus infuenzae strain Rd.
abstract: The lipopolysaccharide of capsule-deficient Haemophilus infuenzae strain Rd contains an N-acetylgalactosamine residue attached to the terminal globotriose moiety in the Hex5 glycoform. Genome analysis identified an open reading frame, HI1578, referred to as LgtD, whose amino acid sequence shows a significant level of similarity to those of a number of bacterial glycosyltransferases involved in lipopolysaccharide biosynthesis. To investigate its function, overexpression and biochemical characterization were performed. Most of the protein was obtained in a highly soluble and active form. Standard glycosyltransferase assay, high-performance liquid chromatography (HPLC), and liquid chromatography (LC)/mass spectrometry (MS) show that LgtD is an N-acetylgalactosaminyltransferase with high donor substrate specificity, and globotriose is a highly preferred acceptor substrate for the enzyme.
authors.affiliation: Department of Biochemistry, The Ohio State University, Columbus, USA.
authors.forename: Kang
authors.initials: K
authors.lastname: Ryu
authors.forename: Steven
authors.initials: S
authors.lastname: Lin
authors.forename: Jun
authors.initials: J
authors.lastname: Shao
authors.forename: Jing
authors.initials: J
authors.lastname: Song
authors.forename: Min
authors.initials: M
authors.lastname: Chen
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Hanfen
authors.initials: H
authors.lastname: Li
authors.forename: Wen
authors.initials: W
authors.lastname: Yi
authors.forename: Peng George
authors.initials: PG
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002240:Carbohydrate Sequence; D005915:Globosides / Q000138:chemical synthesis*; D006193:Haemophilus influenzae / Q000201:enzymology* / Q000235:genetics; D006801:Humans; D008070:Lipopolysaccharides / Q000737:chemistry / Q000378:metabolism; D008969:Molecular Sequence Data; D015394:Molecular Structure; D017350:N-Acetylgalactosaminyltransferases / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D005915:Globosides; D008070:Lipopolysaccharides; C035968:globotetraose; D017350:N-Acetylgalactosaminyltransferases