ABSTRACT
A catecholate siderophore - anachelin - has been isolated from the cyanobacterium Anabaena cylindrica CCAP 1403/2A. The central part of the siderophore is a tripeptide consisting of L-Thr, D-Ser and L-Ser. Its C-terminus is linked amidically to a 1,1-dimethyl-3-amino-1,2,3,4-tetrahydro-7,8-dihydroxyquinolinium system and its N-terminus to 6-amino-3,5,7-trihydroxyheptanoic acid. The 7-hydroxyl group of the latter is esterified with salicylic acid whose carboxyl group is condensed with the 6-amino group to an oxazoline ring. Anachelin is the first genuine siderophore of a cyanobacterium whose structure has been elucidated.
Subject(s)
Anabaena/chemistry , Oligopeptides/chemistry , Quinolinium Compounds/chemistry , Siderophores/chemistry , Models, Molecular , Molecular Conformation , Nuclear Magnetic Resonance, Biomolecular , Oligopeptides/isolation & purification , Quinolinium Compounds/isolation & purification , Spectrometry, Mass, Electrospray Ionization , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , SpectrophotometrySubject(s)
Oligopeptides , Pigments, Biological/biosynthesis , Pigments, Biological/chemistry , Pseudomonas/metabolism , Iron Chelating Agents , Magnetic Resonance Spectroscopy , Models, Molecular , Molecular Structure , Pigments, Biological/isolation & purification , Pseudomonas/growth & developmentABSTRACT
Several suggestions for structures of the siderophores (pyoverdins) from Pseudomonas spp. can be found in the literature which are based on a FAB mass spectrometric analysis only. Availability of two original strains of two Pseudomonas spp. allowed to re-investigate the structure of their pyoverdins. In both cases the amino acid sequence had to be corrected. In addition, D- and L-amino acids could be identified and located in the peptide chain. The knowledge of the correct structures is important in view of an ongoing study to establish relationships between the nature of the peptide chains of pyoverdins and their recognition by outer membrane proteins.
