title: Molecular weight-determination of biosynthetically modified monomeric and oligomeric muropeptides from Escherichia coli by plasma desorption-mass spectrometry.
abstract: The presence of certain D-amino acids in the growth media of Escherichia coli results in the accumulation of 2 major and 3-5 minor new muropeptides in the murein sacculus. Preliminary data suggested that the major muropeptides correspond to a monomer and a cross-linked dimer with one residue of D-amino acid per molecule. We have analyzed several D-amino acid-modified muropeptides by plasma desorption-mass spectrometry. Our results confirmed that the general structures of the major modified muropeptides are: GlucNAc-MurNAc-L-Ala-D-Glu-m-A2pm-D-X, and GlucNAc-MurNAc-L-Ala-D-Glu-m-A2pm-D-Ala; GlucNAc-MurNAc-L-Ala-D-Glu-m-A2pm-D-X, being X a residue of the D-amino acid. These results corroborate the usefulness of this technique for the structural analysis of muropeptides.
authors.affiliation: Centro de Biología Molecular, Universidad Autónoma de Madrid, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Caparrós
authors.forename: E
authors.initials: E
authors.lastname: Pittenauer
authors.forename: E R
authors.initials: ER
authors.lastname: Schmid
authors.forename: M A
authors.initials: MA
authors.lastname: de Pedro
authors.forename: G
authors.initials: G
authors.lastname: Allmaier
mesh_terms: D000596:Amino Acids / Q000032:analysis; D002240:Carbohydrate Sequence; D002473:Cell Wall / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D004926:Escherichia coli / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009842:Oligopeptides / Q000032:analysis*; D010457:Peptidoglycan / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D009842:Oligopeptides; D010457:Peptidoglycan