Staphyloferrin A: a structurally new siderophore from staphylococci

Authors

  • Silvia KONETSCHNY-RAPP,

    1. Institut für Organische Chemie der Universitat Tubingen, Federal Republic of Germany
    Search for more papers by this author
  • Günther JUNG,

    Corresponding author
    1. Institut für Organische Chemie der Universitat Tubingen, Federal Republic of Germany
      Correspondence to G. Jung, Institut für Organische Chemie der Universität Tübingen, Auf der Morgenstelle 18, D-7400 Tübingen, Federal Republic of Germany
    Search for more papers by this author
  • Johannes MEIWES,

    1. Institut für Biologie II, Mikrobiologie I der Universität Tübingen, Federal Republic of Germany
    Search for more papers by this author
  • Hans ZÄHNER

    1. Institut für Biologie II, Mikrobiologie I der Universität Tübingen, Federal Republic of Germany
    Search for more papers by this author

  • Dedication. Dedicated to Prof. Dr Ulrich Schmidt on the occasion of his 65th birthday.

Correspondence to G. Jung, Institut für Organische Chemie der Universität Tübingen, Auf der Morgenstelle 18, D-7400 Tübingen, Federal Republic of Germany

Abstract

Two ferric ion-binding compounds, designated staphyloferrin A and B, were detected in the culture filtrates of staphylococci-grown under iron-deficient conditions. Staphyloferrin A was isolated from cultures of Staphylococcus hyicus DSM 20459. The structural elucidation of this highly hydrophilic, acid-labile compound revealed a novel siderophore, N2,N5-di-(l-oxo-3-hydroxy-3,4-dicarboxybutyl)-D-ornithine, which consists of one ornithine and two citric acid residues linked by two amide bonds. The two citric acid components of staphyloferrin A provide two tridentate pendant ligands, comprising of a β-hydroxy, β-carboxy-substituted carboxylic acid derivative, for octahedral metal chelation. The CD spectrum of the staphyloferrin A ferric complex indicates a predominant A configuration about the ferric ion center. The uptake of ferric staphyloferrin A by S. hyicus obeys Michaelis-Menten kinetics (Km= 0.246 μM; vmax= 82 pmol · mg−1· min−1), indicating active transport of this siderophore. The staphyloferrin A transport system is different from that of the ferrioxamines as shown by an antagonism test. Production of staphyloferrin A is strongly iron-dependent and is stimulated by supplementation of the medium with either D- or L-ornithine. DL-[5-14C]ornithine was incorporated into staphyloferrin A, demonstrating that ornithine is an intermediate in staphyloferrin A biosynthesis.

Ancillary