Ferric ion sequestering agents. 6. The spectrophotometric and potentiometric evaluation of sulfonated tricatecholate ligands

Harris, Wesley R.; Raymond, Kenneth N.; Weitl, Frederick L.

doi:10.1021/ja00400a030

Cited by 143 publications

(102 citation statements)

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“…When the metal-to-ligand ratio approaches 1:1, the color of the solution changes from red to purple. The observed λ max of around 565 nm is consistent with the formation of a bis(catecholate) species (36,37). The Job plot confirms that a λ max around 510 nm is consistent with a metal-to-ligand ratio of 2:3, whereas a λ max around 565 nm is consistent with a metal-toligand ratio of 1:1 (Fig.…”

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confidence: 70%

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Bacteria in an intense competition for iron: Key component of the Campylobacter jejuni iron uptake system scavenges enterobactin hydrolysis product

Raines

Moroz

Blagova

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

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To acquire essential Fe(III), bacteria produce and secrete siderophores with high affinity and selectivity for Fe(III) to mediate its uptake into the cell. Here, we show that the periplasmic binding protein CeuE of Campylobacter jejuni, which was previously thought to bind the Fe(III) complex of the hexadentate siderophore enterobactin (Kd ∼ 0.4 ± 0.1 µM), preferentially binds the Fe(III) complex of the tetradentate enterobactin hydrolysis product bis(2,3-dihydroxybenzoyl-l-Ser) (H5-bisDHBS) (Kd = 10.1 ± 3.8 nM). The protein selects Λ-configured [Fe(bisDHBS)]2− from a pool of diastereomeric Fe(III)-bisDHBS species that includes complexes with metal-to-ligand ratios of 1:1 and 2:3. Cocrystal structures show that, in addition to electrostatic interactions and hydrogen bonding, [Fe(bisDHBS)]2− binds through coordination of His227 and Tyr288 to the iron center. Similar binding is observed for the Fe(III) complex of the bidentate hydrolysis product 2,3-dihydroxybenzoyl-l-Ser, [Fe(monoDHBS)2]3−. The mutation of His227 and Tyr288 to noncoordinating residues (H227L/Y288F) resulted in a substantial loss of affinity for [Fe(bisDHBS)]2− (Kd ∼ 0.5 ± 0.2 µM). These results suggest a previously unidentified role for CeuE within the Fe(III) uptake system of C. jejuni, provide a molecular-level understanding of the underlying binding pocket adaptations, and rationalize reports on the use of enterobactin hydrolysis products by C. jejuni, Vibrio cholerae, and other bacteria with homologous periplasmic binding proteins.

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supporting

confidence: 70%

“…A red complex forms under conditions of excess ligand. The λ max at ∼510 nm is consistent with the formation of a tris(catecholate) species (35,36). When the metal-to-ligand ratio approaches 1:1, the color of the solution changes from red to purple.…”

mentioning

confidence: 57%

Bacteria in an intense competition for iron: Key component of the Campylobacter jejuni iron uptake system scavenges enterobactin hydrolysis product

Raines

Moroz

Blagova

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

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“…5). This is a similar way as pM values are calculated for chelating agents [56], however with this approach the fraction of the hydrolyzed metal ion species, which becomes higher and higher with increasing pH, is also taken into consideration. The higher pM value indicates a stronger metal ion binding ability.…”

Section: Comparison Of Solution Stability and Bioactivity Of Rhcp* Comentioning

confidence: 96%

Comparative solution equilibrium studies on pentamethylcyclopentadienyl rhodium complexes of 2,2ʹ-bipyridine and ethylenediamine and their interaction with human serum albumin

Enyedy

Mészáros

Dömötör

et al. 2015

Journal of Inorganic Biochemistry

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Complex formation equilibrium processes of the (N,N) donor containing 2,2'-bipyridine (bpy) and ethylenediamine (en) with (η 5 -pentamethylcyclopentadienyl)rhodium(III) were investigated in aqueous solution via pH-potentiometry, 1 H NMR spectroscopy, and UV-Vis spectrophotometry in the absence and presence of chloride ions. 2+ , and formation of ternary HSA-RhCp*-ligand adducts was proved. In the case of the deferiprone complex, the RhCp* fragment is cleaved off when HSA is loaded with low equivalents of the compound.

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“…pM se definira za svaki ispitivani ligand u istim uvjetima, konkretno u području fiziološkog pH pri mikromolarnoj množinskoj koncentraciji metala i deset puta većoj množinskoj koncentraciji liganda (c L /c M = 10, c L = 10 −5 M, pH = 7,4). 30 Vrijednosti tog parametra za različite N-alkilne i alkilarilne 3,4-HP i sljedeće katione metala iznose pFe = 17 -22, pAl = 14 -16, pGa = 15 -21. Za eksperimentalno određivanje fizikalno-kemijskih parametara najčešće se primjenjuju već spomenute spektrofotometrijske tehnike, koje se po potrebi ovisno o parametru koji se određuje dodatno kombiniraju potenciometrijskim mjerenjima.…”

Section: 18unclassified

3-Hidroksipiridin-4-oni (I. dio): Priprava i kelirajući učinak

2016

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Ferric ion sequestering agents. 6. The spectrophotometric and potentiometric evaluation of sulfonated tricatecholate ligands

Cited by 143 publications

References 0 publications

Bacteria in an intense competition for iron: Key component of the Campylobacter jejuni iron uptake system scavenges enterobactin hydrolysis product

Bacteria in an intense competition for iron: Key component of the Campylobacter jejuni iron uptake system scavenges enterobactin hydrolysis product

Comparative solution equilibrium studies on pentamethylcyclopentadienyl rhodium complexes of 2,2ʹ-bipyridine and ethylenediamine and their interaction with human serum albumin

3-Hidroksipiridin-4-oni (I. dio): Priprava i kelirajući učinak

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