Iron(III) Uptake and Release by Chrysobactin, a Siderophore of the Phytophatogenic Bacterium Erwinia chrysanthemi

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• 作者：Vladislav Tomiš ; ić ; Sylvie Blanc ; Mourad Elhabiri ; Dominique Expert ; Anne-Marie Albrecht-Gary
• 刊名：Inorganic Chemistry
• 出版年：2008
• 出版时间：October 20, 2008
• 年：2008
• 卷：47
• 期：20
• 页码：9419-9430
• 全文大小：277K
• 年卷期：v.47,no.20(October 20, 2008)
• ISSN：1520-510X

文摘

The plant pathogenic enterobacterium Erwinia chrysanthemi causes important soft-rot disease on a wide range of plants including vegetables and ornamentals of economic importance. It produces a major mono(catecholate) siderophore, chrysobactin (α-N-(2,3-dihydroxybenzoyl)-d-lysyl-l-serine). To unravel the role of chrysobactin in the virulence of E. chrysanthemi, its iron(III) coordination properties were thus investigated in aqueous solutions using electrospray ionization mass spectrometric, potentiometric, and spectrophotometric methods. Moreover, kinetic experiments allowed us to determine the uptake and release mechanisms. The formation mechanism of the 1:1 complex reveals a key role of the terminal carboxylic group of chrysobactin in the binding of either FeOH²⁺ or Fe₂(OH)₂⁴⁺. The proton-driven dissociation of the ferric tris-, bis-, and mono(chrysobactin) complexes was also studied. For these three ferric complexes, a single protonation triggers the release of the bound chrysobactin molecule. Interestingly, the dissociation of the last ligand proceeded via the formation of an intermediate for which a salicylate-type mode of bonding was proposed.