title: Solid-state NMR characterization of amphomycin effects on peptidoglycan and wall teichoic acid biosyntheses in Staphylococcus aureus.
abstract: Amphomycin and MX-2401 are cyclic lipopeptides exhibiting bactericidal activities against Gram-positive pathogens. Amphomycin and MX-2401 share structural similarities with daptomycin, but unlike daptomycin they do not target bacterial membrane. In this study, we investigate in vivo modes of action for amphomycin and MX-2401 in intact whole cells of Staphylococcus aureus by measuring the changes of peptidoglycan and wall teichoic acid compositions using solid-state NMR. S. aureus were grown in a defined media containing isotope labels [1-(13)C]glycine and L-[ε-(15)N]lysin, L-[1-(13)C]lysine and D-[(15)N]alanine, or D-[1-(13)C]alanine and [(15)N]glycine, to selectively (13)C-(15)N pair label peptidoglycan bridge-link, stem-link, and cross-link, respectively. (13)C{(15)N} and (15)N{(13)C} rotational-echo double resonance NMR measurements determined that cyclic lipopeptide-treated S. aureus exhibited thinning of the cell wall, accumulation of Park's nucleotide, inhibition of glycine utilization for purine biosynthesis, reduction of ester-linked D-Ala in teichoic acids, and reduction of peptidoglycan cross-linking. Whole cell NMR analysis also revealed that S. aureus, in presence of amphomycin and MX-2401, maintained the incorporation of D-Ala during peptidoglycan biosynthesis while the incorporation of D-Ala into teichoic acids was inhibited. These effects are consistent with amphomycin's dual inhibition of both peptidoglycan and wall teichoic acid biosyntheses in S. aureus.
authors.affiliation: Department of Chemistry, Washington University, One Brookings Drive, St. Louis, MO 63130, USA.
authors.forename: Manmilan
authors.initials: M
authors.lastname: Singh
authors.affiliation: Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, TX 76798, USA.
authors.forename: James
authors.initials: J
authors.lastname: Chang
authors.affiliation: Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, TX 76798, USA.
authors.forename: Lauryn
authors.initials: L
authors.lastname: Coffman
authors.affiliation: Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, TX 76798, USA.
authors.forename: Sung Joon
authors.initials: SJ
authors.lastname: Kim
mesh_terms: D055666:Lipopeptides / Q000494:pharmacology*; D019906:Nuclear Magnetic Resonance, Biomolecular; D010457:Peptidoglycan / Q000096:biosynthesis*; D013211:Staphylococcus aureus / Q000378:metabolism*; D013682:Teichoic Acids / Q000096:biosynthesis*
chemical_list: D055666:Lipopeptides; D010457:Peptidoglycan; D013682:Teichoic Acids; C004423:amphomycin