HOMEPRODUCTSCOMPANYCONTACTFAQResearchDictionaryPharmaSign Up FREE or Login

Purification and structural characterization of siderophore (corynebactin) from Corynebacterium diphtheriae.

Abstract
During infection, Corynebacterium diphtheriae must compete with host iron-sequestering mechanisms for iron. C. diphtheriae can acquire iron by a siderophore-dependent iron-uptake pathway, by uptake and degradation of heme, or both. Previous studies showed that production of siderophore (corynebactin) by C. diphtheriae is repressed under high-iron growth conditions by the iron-activated diphtheria toxin repressor (DtxR) and that partially purified corynebactin fails to react in chemical assays for catecholate or hydroxamate compounds. In this study, we purified corynebactin from supernatants of low-iron cultures of the siderophore-overproducing, DtxR-negative mutant strain C. diphtheriae C7(β) ΔdtxR by sequential anion-exchange chromatography on AG1-X2 and Source 15Q resins, followed by reverse-phase high-performance liquid chromatography (RP-HPLC) on Zorbax C8 resin. The Chrome Azurol S (CAS) chemical assay for siderophores was used to detect and measure corynebactin during purification, and the biological activity of purified corynebactin was shown by its ability to promote growth and iron uptake in siderophore-deficient mutant strains of C. diphtheriae under iron-limiting conditions. Mass spectrometry and NMR analysis demonstrated that corynebactin has a novel structure, consisting of a central lysine residue linked through its α- and ε- amino groups by amide bonds to the terminal carboxyl groups of two different citrate residues. Corynebactin from C. diphtheriae is structurally related to staphyloferrin A from Staphylococcus aureus and rhizoferrin from Rhizopus microsporus in which d-ornithine or 1,4-diaminobutane, respectively, replaces the central lysine residue that is present in corynebactin.
AuthorsSheryl Zajdowicz, Jon C Haller, Amy E Krafft, Steve W Hunsucker, Colin T Mant, Mark W Duncan, Robert S Hodges, David N M Jones, Randall K Holmes
JournalPloS one (PLoS One) Vol. 7 Issue 4 Pg. e34591 ( 2012) ISSN: 1932-6203 [Electronic] United States
PMID22514641 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
Chemical References
  • Citrates
  • Ferric Compounds
  • Siderophores
  • staphyloferrin A
  • rhizoferrin
  • Enterobactin
  • corynebactin
  • Iron
  • Ornithine
Topics
  • Biological Transport (drug effects)
  • Citrates (chemistry)
  • Corynebacterium diphtheriae (drug effects, metabolism)
  • Enterobactin (analogs & derivatives, chemistry, isolation & purification, pharmacology)
  • Ferric Compounds (chemistry)
  • Iron (metabolism)
  • Magnetic Resonance Spectroscopy
  • Ornithine (analogs & derivatives, chemistry)
  • Siderophores (chemistry, isolation & purification, pharmacology)
  • Spectrometry, Mass, Electrospray Ionization

Join CureHunter, for free Research Interface BASIC access!

Take advantage of free CureHunter research engine access to explore the best drug and treatment options for any disease. Find out why thousands of doctors, pharma researchers and patient activists around the world use CureHunter every day.
Realize the full power of the drug-disease research graph!


Choose Username:
Email:
Password:
Verify Password:
Enter Code Shown: