A new glycosylated lipopeptide incorporated into the cell wall of a smooth variant of Gordona hydrophobica.
A cell wall component of a smooth variant of Gordona hydrophobica 1775/15 was isolated and purified, and its structure was determined by various chemical methods, including chemical synthesis of part structures, Edman degradation, gas chromatography/mass spectrometry analysis, matrix-assisted laser desorption ionization-post-source decay (MALDI-PSD) tandem mass spectrometry, and 1H and 13C NMR using one- and two-dimensional, homo- and heteronuclear correlated spectroscopy. The cell wall component was found to be a (mono-) glycosylated peptidolipid (GPL) consisting of a tridecapeptide interlinked by a beta-hydroxylated fatty acid (3-hydroxyeicosanoic acid, 20:0 (3-OH)) to form a cyclic lactone ring structure. The main fraction of GPL, for which we propose the name gordonin, was identified as 3-hydroxyeicosanoyl-L-seryl-L-phenylalanyl-L-seryl- L-seryl-D-alanyl-L -(O-beta-D-glucopyranosyl)-threonyl-glycyl-D-leucyl-L-valyl-L-seryl-L -phenylalanyl-glycyl-L-valyl lactone. The other GPLs constitute structural variations within the nature of the beta-hydroxylated fatty acid (20:0(3-OH) versus 22:1(3-OH)) in a ratio of about 1:0.9 as well as within one amino acid (D-Leu versus L-Phe) in about 30%. Sequence information was obtained in part by Edman degradation as well as gas chromatography/mass spectrometry analysis of di- and tripeptide fragments. However, the complete amino acid sequence could only be established by MALDI-PSD from the linear molecule, i.e. after ring opening of the lactone. In contrast, rough variants of G. hydrophobica 1775/15 lack these peptidolipids or synthesize them to a much lesser extent indicating that gordonin contributes significantly to the physicochemical character of the cell surface.
Moormann
M
M
Abteilung Mikrobiologie, Universität Osnabrück, D-49069 Osnabrück, Federal Republic of Germany.
Zähringer
U
U
Moll
H
H
Kaufmann
R
R
Schmid
R
R
Altendorf
K
K
D000192:Actinomycetales / Q000737:chemistry* / Q000145:classification; D000595:Amino Acid Sequence; D002473:Cell Wall / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D005227:Fatty Acids / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry; D006001:Glycoconjugates / Q000737:chemistry* / Q000302:isolation & purification; D006031:Glycosylation; D055666:Lipopeptides; D009682:Magnetic Resonance Spectroscopy; D009842:Oligopeptides / Q000737:chemistry* / Q000302:isolation & purification; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D005227:Fatty Acids; D006001:Glycoconjugates; D055666:Lipopeptides; D009842:Oligopeptides; C105472:gordonin