title: Characterization of the peptidoglycan of vancomycin-susceptible Enterococcus faecium.
abstract: Vancomycin and other antibacterial glycopeptide analogues target the cell wall and affect the enzymatic processes involved with cell-wall biosynthesis. Understanding the structure and organization of the peptidoglycan is the first step in establishing the mode of action of these glycopeptides. We have used solid-state NMR to determine the relative concentrations of stem-links (64%), bridge-links (61%), and cross-links (49%) in the cell walls of vancomycin-susceptible Enterococcus faecium (ATTC 49624). Furthermore, we have determined that in vivo only 7% of the peptidoglycan stems terminate in d-Ala- d-Ala, the well-known vancomycin-binding site. Presumably, d-Ala- d-Ala is cleaved from uncross-linked stems in mature peptidoglycan by an active carboxypeptidase. We believe that most of the few pentapeptide stems ending in d-Ala- d-Ala occur in the template and nascent peptidoglycan strands that are crucial for cell-wall biosynthesis.
authors.affiliation: Department of Chemistry, Washington University, One Brookings Drive, St. Louis, Missouri 63130, USA.
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Patti
authors.forename: Sung Joon
authors.initials: SJ
authors.lastname: Kim
authors.forename: Jacob
authors.initials: J
authors.lastname: Schaefer
mesh_terms: D002473:Cell Wall / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D016984:Enterococcus faecium / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D008826:Microbial Sensitivity Tests / Q000379:methods; D010457:Peptidoglycan / Q000737:chemistry* / Q000378:metabolism; D013211:Staphylococcus aureus / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D014640:Vancomycin / Q000494:pharmacology*; D020713:Vancomycin Resistance
chemical_list: D010457:Peptidoglycan; D014640:Vancomycin