1
|
Frei A, Verderosa AD, Elliott AG, Zuegg J, Blaskovich MAT. Metals to combat antimicrobial resistance. Nat Rev Chem 2023; 7:202-224. [PMID: 37117903 PMCID: PMC9907218 DOI: 10.1038/s41570-023-00463-4] [Citation(s) in RCA: 89] [Impact Index Per Article: 89.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/06/2023] [Indexed: 02/10/2023]
Abstract
Bacteria, similar to most organisms, have a love-hate relationship with metals: a specific metal may be essential for survival yet toxic in certain forms and concentrations. Metal ions have a long history of antimicrobial activity and have received increasing attention in recent years owing to the rise of antimicrobial resistance. The search for antibacterial agents now encompasses metal ions, nanoparticles and metal complexes with antimicrobial activity ('metalloantibiotics'). Although yet to be advanced to the clinic, metalloantibiotics are a vast and underexplored group of compounds that could lead to a much-needed new class of antibiotics. This Review summarizes recent developments in this growing field, focusing on advances in the development of metalloantibiotics, in particular, those for which the mechanism of action has been investigated. We also provide an overview of alternative uses of metal complexes to combat bacterial infections, including antimicrobial photodynamic therapy and radionuclide diagnosis of bacterial infections.
Collapse
Affiliation(s)
- Angelo Frei
- Community for Open Antimicrobial Drug Discovery, Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, Australia.
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland.
| | - Anthony D Verderosa
- Community for Open Antimicrobial Drug Discovery, Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, Australia
| | - Alysha G Elliott
- Community for Open Antimicrobial Drug Discovery, Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, Australia
| | - Johannes Zuegg
- Community for Open Antimicrobial Drug Discovery, Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, Australia
| | - Mark A T Blaskovich
- Community for Open Antimicrobial Drug Discovery, Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, Australia.
| |
Collapse
|
2
|
Baranska NG, Parkin A, Duhme-Klair AK. Electrochemical and Solution Structural Characterization of Fe(III) Azotochelin Complexes: Examining the Coordination Behavior of a Tetradentate Siderophore. Inorg Chem 2022; 61:19172-19182. [PMID: 36251475 DOI: 10.1021/acs.inorgchem.2c02777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report an electrochemical setup comprising a boron-doped diamond (BDD) working electrode for the electrochemical study of iron(III) catecholate siderophores. We demonstrate its successful application in the voltammetric investigation of iron(III) azotochelin, an iron complex of a bis(catecholate) siderophore. Cyclic voltammetry results, when complemented by UV-vis and native electrospray ionization-mass spectrometry (ESI-MS) characterization, reveal the formation of a coordinatively unsaturated tetracoordinate 1:1 complex of Fe:azotochelin (M1:L1) at neutral pH, contrary to iron(III) tetradentate siderophore complexes of other classes which favor the hexacoordinate environment of an M2:L3 species. A notable effect of pH and buffer composition on the reduction potential of iron(III) azotochelin is demonstrated. Lower pH values and buffers encompassing primary or secondary amines facilitate a positive potential shift of up to +290 mV and +250 mV vs Ag/AgCl 3 M NaCl, respectively. The study was extended to the investigation of the iron(III) complexes of hexadentate siderophores. For tris(catecholate) siderophores, enterobactin and protochelin, the reduction potentials were found to lie beyond the potential window accessible to the BDD electrode; however, we were successful in observing the electrochemical behavior of a tris(hydroxamate) siderophore, ferricrocin.
Collapse
Affiliation(s)
- Natalia G Baranska
- Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Alison Parkin
- Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Anne-K Duhme-Klair
- Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom
| |
Collapse
|
3
|
Brown CJM, Codd R. Directing macrocyclic architecture using iron(III)-, gallium(III)-, or zirconium(IV)-assisted ring closure of linear dimeric endo-hydroxamic acid ligands. J Inorg Biochem 2020; 216:111337. [PMID: 33360106 DOI: 10.1016/j.jinorgbio.2020.111337] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 11/11/2020] [Accepted: 12/04/2020] [Indexed: 11/17/2022]
Abstract
Dimeric hydroxamic acid macrocycles are a subclass of bacterial siderophores produced for iron acquisition. Limited yields from natural sources provides the impetus to develop synthetic routes to improve access to these compounds, which have potential utility in metal ion binding applications in the environment and medicine. This work has examined the role of metal ions in forming pre-complexes with linear endo-hydroxamic acid (endo-HXA) ligands bearing terminal amine and carboxylic acid groups optimally configured for in situ ring closure reactions. The 1:1 reaction between Fe(III) and the dimeric endo-HXA ligand 5-((5-(5-((5-aminopentyl)(hydroxy)amino)-5-oxopentanamido)pentyl)(hydroxy)amino)-5-oxopentanoic acid (PPH-PPH) (1) formed the pre-complex (PC) [Fe(PP-PP)-PC]+ with in situ amide coupling generating the macrocycle (MC) [Fe(PP)2-MC]+ and, following Fe(III) removal, the apo-macrocycle 1,13-dihydroxy-1,7,13,19-tetraazacyclotetracosane-2,6,14,18-tetraone (PPH)2-MC (2). The 1:2 reaction system between Fe(III) and the monomeric endo-HXA ligand 5-((5-aminopentyl)(hydroxy)amino)-5-oxopentanoic acid (PPH) gave significantly less [Fe(PP)2-MC]+ than the former system, due to the requirement to form two rather than one amide bond(s). The 1:1 Ga(III):1 system yielded [Ga(PP-PP)-PC]+ and [Ga(PP)2-MC]+. Neither [Zr(PP-PP)-PC]2+ nor [Zr(PP)2-MC]2+ was detected in the 1:1 Zr(IV):1 system. Instead, the Zr(IV) system showed the formation of a 1:2 Zr(IV):1 pre-complex [Zr(PP-PP)2-PC], which following in situ amide bond forming chemistry, generated two Zr(IV) macrocyclic complexes with distinct architectures: a dimer-of-dimers complex [Zr((PP)2)2-MC] and an end-to-end macrocycle [Zr(PP)4-MC]. The formation of [Fe(PP)2-MC]+, [Ga(PP)2-MC]+ or [Zr((PP)2)2-MC] was confirmed from reconstitution experiments with 2. The work has shown that the choice of metal ion in metal-assisted ring closure reactions directs the assembly of macrocyclic complexes with distinct architectures.
Collapse
Affiliation(s)
- Christopher J M Brown
- The University of Sydney, School of Medical Sciences (Pharmacology), New South Wales 2006, Australia
| | - Rachel Codd
- The University of Sydney, School of Medical Sciences (Pharmacology), New South Wales 2006, Australia.
| |
Collapse
|
4
|
Kosyakovsky J, Witthuhn BA, Svitak AL, Frey WH, Hanson LR, Fine JM. Quantifying Intranasally Administered Deferoxamine in Rat Brain Tissue with Mass Spectrometry. ACS Chem Neurosci 2019; 10:4571-4578. [PMID: 31573798 DOI: 10.1021/acschemneuro.9b00436] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Deferoxamine, a metal chelator, has been shown to be neuroprotective in animal models of ischemic stroke, traumatic brain injury and both subarachnoid and intracerebral hemorrhage. Intranasal deferoxamine (IN DFO) has also shown promise as a potential treatment for multiple neurodegenerative diseases, including Parkinson's and Alzheimer's. However, there have been no attempts to thoroughly understand the dynamics and pharmacokinetics of IN DFO. We developed a new high-performance liquid-chromatography electrospray-tandem mass spectrometry (HPLC/ESI-MS2) method to quantify the combined total levels of DFO, ferrioxamine (FO; DFO bound to iron), and aluminoxamine (AO; aluminum-bound DFO) in brain tissue using a custom-synthesized deuterated analogue (DFO-d7, Medical Isotopes Inc., Pelham NH) as an internal standard. We applied our method toward understanding the pharmacokinetics of IN DFO delivery to the brain and blood of rats from 15 min to 4 h after delivery. We found that IN delivery successfully targets DFO to the brain to achieve concentrations of 0.5-15 μM in various brain regions within 15 min, and decreasing though still detectable after 4 h. Systemic exposure was minimized as assessed by concentration in blood serum. Serum concentrations were 0.02 μM at 15 min and no more than 0.1 μM at later time points. Compared to blood serum, brain region-specific drug exposure (as measured by area under the curve) ranged from slightly under 10 times exposure in the hippocampus to almost 200 times exposure in the olfactory bulb with IN DFO delivery. These findings represent a major step toward future method development, pharmacokinetic studies, and clinical trials for this promising therapeutic.
Collapse
Affiliation(s)
- Jacob Kosyakovsky
- HealthPartners Neuroscience Center, HealthPartners Institute, Saint Paul, Minnesota 55130, United States
| | - Bruce A. Witthuhn
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota 55108, United States
| | - Aleta L. Svitak
- HealthPartners Neuroscience Center, HealthPartners Institute, Saint Paul, Minnesota 55130, United States
| | - William H. Frey
- HealthPartners Neuroscience Center, HealthPartners Institute, Saint Paul, Minnesota 55130, United States
| | - Leah R. Hanson
- HealthPartners Neuroscience Center, HealthPartners Institute, Saint Paul, Minnesota 55130, United States
| | - Jared M. Fine
- HealthPartners Neuroscience Center, HealthPartners Institute, Saint Paul, Minnesota 55130, United States
| |
Collapse
|
5
|
Codd R, Soe CZ, Pakchung AAH, Sresutharsan A, Brown CJM, Tieu W. The chemical biology and coordination chemistry of putrebactin, avaroferrin, bisucaberin, and alcaligin. J Biol Inorg Chem 2018; 23:969-982. [PMID: 29946977 DOI: 10.1007/s00775-018-1585-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 06/20/2018] [Indexed: 12/30/2022]
Abstract
Dihydroxamic acid macrocyclic siderophores comprise four members: putrebactin (putH2), avaroferrin (avaH2), bisucaberin (bisH2), and alcaligin (alcH2). This mini-review collates studies of the chemical biology and coordination chemistry of these macrocycles, with an emphasis on putH2. These Fe(III)-binding macrocycles are produced by selected bacteria to acquire insoluble Fe(III) from the local environment. The macrocycles are optimally pre-configured for Fe(III) binding, as established from the X-ray crystal structure of dinuclear [Fe2(alc)3] at neutral pH. The dimeric macrocycles are biosynthetic products of two endo-hydroxamic acid ligands flanked by one amine group and one carboxylic acid group, which are assembled from 1,4-diaminobutane and/or 1,5-diaminopentane as initial substrates. The biosynthesis of alcH2 includes an additional diamine C-hydroxylation step. Knowledge of putH2 biosynthesis supported the use of precursor-directed biosynthesis to generate unsaturated putH2 analogues by culturing Shewanella putrefaciens in medium supplemented with unsaturated diamine substrates. The X-ray crystal structures of putH2, avaH2 and alcH2 show differences in the relative orientations of the amide and hydroxamic acid functional groups that could prescribe differences in solvation and other biological properties. Functional differences have been borne out in biological studies. Although evolved for Fe(III) acquisition, solution coordination complexes have been characterised between putH2 and oxido-V(IV/V), Mo(VI), or Cr(V). Retrosynthetic analysis of 1:1 complexes of [Fe(put)]+, [Fe(ava)]+, and [Fe(bis)]+ that dominate at pH < 5 led to a forward metal-templated synthesis approach to generate the Fe(III)-loaded macrocycles, with apo-macrocycles furnished upon incubation with EDTA. This mini-review aims to capture the rich chemistry and chemical biology of these seemingly simple compounds.
Collapse
Affiliation(s)
- Rachel Codd
- School of Medical Sciences (Pharmacology) and Bosch Institute, The University of Sydney, Sydney, NSW, 2006, Australia.
| | - Cho Zin Soe
- School of Medical Sciences (Pharmacology) and Bosch Institute, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Amalie A H Pakchung
- School of Medical Sciences (Pharmacology) and Bosch Institute, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Athavan Sresutharsan
- School of Medical Sciences (Pharmacology) and Bosch Institute, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Christopher J M Brown
- School of Medical Sciences (Pharmacology) and Bosch Institute, The University of Sydney, Sydney, NSW, 2006, Australia
| | - William Tieu
- School of Medical Sciences (Pharmacology) and Bosch Institute, The University of Sydney, Sydney, NSW, 2006, Australia
| |
Collapse
|
6
|
Nakao M. Development of Novel Functional Molecules Based on the Molecular Structure Characteristics of Diketopiperazines. YAKUGAKU ZASSHI 2017; 137:1505-1516. [DOI: 10.1248/yakushi.17-00176] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Michiyasu Nakao
- Graduate School of Pharmaceutical Sciences, Tokushima University
| |
Collapse
|
7
|
Sidebottom AM, Karty JA, Carlson EE. Accurate mass MS/MS/MS analysis of siderophores ferrioxamine B and E1 by collision-induced dissociation electrospray mass spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2015; 26:1899-1902. [PMID: 26323615 DOI: 10.1007/s13361-015-1242-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 07/17/2015] [Accepted: 07/23/2015] [Indexed: 06/04/2023]
Abstract
Siderophores are bacterially secreted, small molecule iron chelators that facilitate the binding of insoluble iron (III) for reuptake and use in various biological processes. These compounds are classified by their iron (III) binding geometry, as dictated by subunit composition and include groups such as the trihydroxamates (hexadentate ligand) and catecholates (bidentate). Small modifications to the core structure such as acetylation, lipid tail addition, or cyclization, make facile characterization of new siderophores difficult by molecular ion detection alone (MS(1)). We have expanded upon previous fragmentation-directed studies using electrospray ionization collision-induced dissociation tandem mass spectrometry (ESI-CID-MS/MS/MS) and identified diagnostic MS(3) features from the trihydroxamate siderophore class for ferrioxamine B and E1 by accurate mass. Diagnostic features for MS(3) include C-C, C-N, amide, and oxime cleavage events with proposed losses of water and -CO from the iron (III) coordination sites. These insights will facilitate the discovery of novel trihydroxamate siderophores from complex sample matrices. Graphical Abstract ᅟ.
Collapse
Affiliation(s)
| | - Jonathan A Karty
- Department of Chemistry, Indiana University, Bloomington, IN, 47403, USA
| | - Erin E Carlson
- Department of Chemistry, Indiana University, Bloomington, IN, 47403, USA.
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, 47403, USA.
- Department of Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis, MN, 55455, USA.
| |
Collapse
|
8
|
Magnetic susceptibility of Mn(III) complexes of hydroxamate siderophores. J Inorg Biochem 2015; 148:22-6. [PMID: 25978931 DOI: 10.1016/j.jinorgbio.2015.04.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 04/23/2015] [Accepted: 04/24/2015] [Indexed: 11/23/2022]
Abstract
The hydroxamate siderophores putrebactin, desferrioxamine B, and desferrioxamine E bind Mn(II) and promote the air oxidation of Mn(II) to Mn(III) at pH>7.1. The magnetic susceptibility of the manganese complexes were determined by the Evans method and the stoichiometry was probed with electrospray ionization mass spectrometry (ESIMS). The room temperature magnetic moments (μeff) for the manganese complexes of desferrioxamines B and E were 4.85 BM and 4.84 BM, respectively, consistent with a high spin, d(4), Mn(III) electronic configuration. The manganese complex of putrebactin had a magnetic moment of 4.98 BM, consistent with incomplete oxidation of Mn(II), as confirmed by X band EPR spectroscopy. Mass spectra of the Mn(III) desferrioxamine B and E complexes showed complexes at m/z 613.26 and 653.26, respectively, consistent with 1:1 complexation. Mass spectral peaks for manganese putrebactin at m/z 797.31 and 1221.41 corresponds to 1:2 and 2:3 Mn:putrebactin complexation. This study directly confirms the Mn(III) oxidation state in hydroxamate siderophore complexes.
Collapse
|
9
|
Lifa T, Tieu W, Hocking RK, Codd R. Forward and Reverse (Retro) Iron(III) or Gallium(III) Desferrioxamine E and Ring-Expanded Analogues Prepared Using Metal-Templated Synthesis from endo-Hydroxamic Acid Monomers. Inorg Chem 2015; 54:3573-83. [DOI: 10.1021/acs.inorgchem.5b00141] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Tulip Lifa
- School of Medical Sciences (Pharmacology) and Bosch Institute, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - William Tieu
- School of Medical Sciences (Pharmacology) and Bosch Institute, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Rosalie K. Hocking
- College of Science, Technology & Engineering, James Cook University, Townsville, Queensland 4811, Australia
| | - Rachel Codd
- School of Medical Sciences (Pharmacology) and Bosch Institute, The University of Sydney, Sydney, New South Wales 2006, Australia
| |
Collapse
|
10
|
Sano S, Nakao M, Fukayama S, Kitaike S. Synthesis of Rhodotorulic Acid and Its 1,4-Dimethylated Derivative. HETEROCYCLES 2015. [DOI: 10.3987/com-14-s(k)67] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
11
|
Nurchi VM, Crisponi G, Arca M, Crespo-Alonso M, Lachowicz JI, Mansoori D, Toso L, Pichiri G, Amelia Santos M, Marques SM, Niclós-Gutiérrez J, González-Pérez JM, Domínguez-Martín A, Choquesillo-Lazarte D, Szewczuk Z, Antonietta Zoroddu M, Peana M. A new bis-3-hydroxy-4-pyrone as a potential therapeutic iron chelating agent. Effect of connecting and side chains on the complex structures and metal ion selectivity. J Inorg Biochem 2014; 141:132-143. [DOI: 10.1016/j.jinorgbio.2014.09.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 09/03/2014] [Accepted: 09/03/2014] [Indexed: 01/02/2023]
|
12
|
Krasnoff SB, Keresztes I, Donzelli BGG, Gibson DM. Metachelins, mannosylated and N-oxidized coprogen-type siderophores from Metarhizium robertsii. JOURNAL OF NATURAL PRODUCTS 2014; 77:1685-1692. [PMID: 24992511 DOI: 10.1021/np500300s] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Under iron-depleted culture conditions, the entomopathogenic fungus Metarhizium robertsii (Bischoff, Humber, and Rehner) (= M. anisopliae) produces a complex of extracellular siderophores including novel O-glycosylated and N-oxidized coprogen-type compounds as well as the known fungal siderophores N(α)-dimethylcoprogen (NADC) and dimerumic acid (DA). Metachelin A (1), the most abundant component in the M. robertsii siderophore mixture, was characterized as a 1094 Da analogue of NADC that is O-glycosylated by β-mannose at both terminal hydroxyl groups and N-oxidized at the dimethylated α-nitrogen. The mixture also contained a 1078 Da analogue, metachelin B (2), which lacks the N-oxide modification. Also characterized were the aglycone of 1, i.e., the N-oxide of NADC (3), and the monomannoside of DA (6). N-Oxide and O-glycosyl substituents are unprecedented among microbial siderophores. At high ESIMS source energy and at room temperature in DMSO, 1 underwent Cope elimination, resulting in loss of the N(α)-dimethyl group and dehydration of the α-β bond. High-resolution ESIMS data confirmed that all tri- and dihydroxamate siderophores (1-6) complex with trivalent Fe, Al, and Ga. In a chrome azurol S assay, all of the M. robertsii siderophores showed iron-binding activity roughly equivalent to that of desferrioxamine B.
Collapse
Affiliation(s)
- Stuart B Krasnoff
- USDA-ARS-Biological IPM Research Unit, Ithaca, New York 14853, United States
| | | | | | | |
Collapse
|
13
|
Soe CZ, Pakchung AAH, Codd R. Dinuclear [(VVO(putrebactin))2(μ-OCH3)2] Formed in Solution as Established from LC-MS Measurements Using 50V-Enriched V2O5. Inorg Chem 2014; 53:5852-61. [DOI: 10.1021/ic500787v] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Cho Zin Soe
- School of Medical Sciences (Pharmacology) and Bosch Institute and ‡School of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Amalie A. H. Pakchung
- School of Medical Sciences (Pharmacology) and Bosch Institute and ‡School of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Rachel Codd
- School of Medical Sciences (Pharmacology) and Bosch Institute and ‡School of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia
| |
Collapse
|
14
|
Soe CZ, Codd R. Unsaturated macrocyclic dihydroxamic acid siderophores produced by Shewanella putrefaciens using precursor-directed biosynthesis. ACS Chem Biol 2014; 9:945-56. [PMID: 24483365 DOI: 10.1021/cb400901j] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
To acquire iron essential for growth, the bacterium Shewanella putrefaciens produces the macrocyclic dihydroxamic acid putrebactin (pbH2; [M + H(+)](+), m/zcalc 373.2) as its native siderophore. The assembly of pbH2 requires endogenous 1,4-diaminobutane (DB), which is produced from the ornithine decarboxylase (ODC)-catalyzed decarboxylation of l-ornithine. In this work, levels of endogenous DB were attenuated in S. putrefaciens cultures by augmenting the medium with the ODC inhibitor 1,4-diamino-2-butanone (DBO). The presence in the medium of DBO together with alternative exogenous non-native diamine substrates, (15)N2-1,4-diaminobutane ((15)N2-DB) or 1,4-diamino-2(E)-butene (E-DBE), resulted in the respective biosynthesis of (15)N-labeled pbH2 ((15)N4-pbH2; [M + H(+)](+), m/zcalc 377.2, m/zobs 377.2) or the unsaturated pbH2 variant, named here: E,E-putrebactene (E,E-pbeH2; [M + H(+)](+), m/zcalc 369.2, m/zobs 369.2). In the latter system, remaining endogenous DB resulted in the parallel biosynthesis of the monounsaturated DB-E-DBE hybrid, E-putrebactene (E-pbxH2; [M + H(+)](+), m/zcalc 371.2, m/zobs 371.2). These are the first identified unsaturated macrocyclic dihydroxamic acid siderophores. LC-MS measurements showed 1:1 complexes formed between Fe(III) and pbH2 ([Fe(pb)](+); [M](+), m/zcalc 426.1, m/zobs 426.2), (15)N4-pbH2 ([Fe((15)N4-pb)](+); [M](+), m/zcalc 430.1, m/zobs 430.1), E,E-pbeH2 ([Fe(E,E-pbe)](+); [M](+), m/zcalc 422.1, m/zobs 422.0), or E-pbxH2 ([Fe(E-pbx)](+); [M](+), m/zcalc 424.1, m/zobs 424.2). The order of the gain in siderophore-mediated Fe(III) solubility, as defined by the difference in retention time between the free ligand and the Fe(III)-loaded complex, was pbH2 (ΔtR = 8.77 min) > E-pbxH2 (ΔtR = 6.95 min) > E,E-pbeH2 (ΔtR = 6.16 min), which suggests one possible reason why nature has selected for saturated rather than unsaturated siderophores as Fe(III) solubilization agents. The potential to conduct multiple types of ex situ chemical conversions across the double bond(s) of the unsaturated macrocycles provides a new route to increased molecular diversity in this class of siderophore.
Collapse
Affiliation(s)
- Cho Z. Soe
- School of Medical Sciences
(Pharmacology) and Bosch Institute, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Rachel Codd
- School of Medical Sciences
(Pharmacology) and Bosch Institute, The University of Sydney, Sydney, New South Wales 2006, Australia
| |
Collapse
|
15
|
Zhu J, Li DF, Kong XL, Hider RC, Zhou T. Coordination chemistry of a bis(3-hydroxypyran-4-one) with iron and copper. J COORD CHEM 2013. [DOI: 10.1080/00958972.2013.818670] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Ju Zhu
- a School of Biological and Chemical Engineering, Zhejiang University of Science and Technology , Hangzhou , P.R. China
| | - Dong-Fang Li
- b School of Food Science and Biotechnology, Zhejiang Gongshang University , Hangzhou , P.R. China
| | - Xiao-Le Kong
- c Division of Pharmaceutical Science , King’s College London , London , UK
| | - Robert C. Hider
- c Division of Pharmaceutical Science , King’s College London , London , UK
| | - Tao Zhou
- b School of Food Science and Biotechnology, Zhejiang Gongshang University , Hangzhou , P.R. China
| |
Collapse
|
16
|
Fate of ferrisiderophores after import across bacterial outer membranes: different iron release strategies are observed in the cytoplasm or periplasm depending on the siderophore pathways. Amino Acids 2013; 44:1267-77. [PMID: 23443998 DOI: 10.1007/s00726-013-1468-2] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Accepted: 02/09/2013] [Indexed: 12/22/2022]
Abstract
Siderophore production and utilization is one of the major strategies deployed by bacteria to get access to iron, a key nutrient for bacterial growth. The biological function of siderophores is to solubilize iron in the bacterial environment and to shuttle it back to the cytoplasm of the microorganisms. This uptake process for Gram-negative species involves TonB-dependent transporters for translocation across the outer membranes. In Escherichia coli and many other Gram-negative bacteria, ABC transporters associated with periplasmic binding proteins import ferrisiderophores across cytoplasmic membranes. Recent data reveal that in some siderophore pathways, this step can also be carried out by proton-motive force-dependent permeases, for example the ferrichrome and ferripyochelin pathways in Pseudomonas aeruginosa. Iron is then released from the siderophores in the bacterial cytoplasm by different enzymatic mechanisms depending on the nature of the siderophore. Another strategy has been reported for the pyoverdine pathway in P. aeruginosa: iron is released from the siderophore in the periplasm and only siderophore-free iron is transported into the cytoplasm by an ABC transporter having two atypical periplasmic binding proteins. This review presents recent findings concerning both ferrisiderophore and siderophore-free iron transport across bacterial cytoplasmic membranes and considers current knowledge about the mechanisms involved in iron release from siderophores.
Collapse
|
17
|
Pakchung AAH, Lifa T, Codd R. Solution species of Fe(iii), Ga(iii), In(iii) or Ln(iii) and suberodihydroxamic acid from electrospray ionization mass spectrometry. RSC Adv 2013. [DOI: 10.1039/c3ra40437d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
18
|
Schalk IJ, Mislin GLA, Brillet K. Structure, function and binding selectivity and stereoselectivity of siderophore-iron outer membrane transporters. CURRENT TOPICS IN MEMBRANES 2012; 69:37-66. [PMID: 23046646 DOI: 10.1016/b978-0-12-394390-3.00002-1] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
To get access to iron, microorganisms produce and release into their environment small organic metal chelators called siderophores. In parallel, they produce siderophore-iron outer membrane transporters (also called TonB-Dependent Transporters or TBDT) embedded in the outer membrane; these proteins actively reabsorb the siderophore loaded with iron from the extracellular medium. This active uptake requires energy in the form of the proton motive force transferred from the inner membrane to the outer membrane transporter via the inner membrane TonB complex. Siderophores produced by microorganisms are structurally very diverse with molecular weights of 150 up to 2000Da. Siderophore-iron uptake from the extracellular medium by TBDTs is a highly selective and sometimes even stereoselective process, with each siderophore having a specific TBDT. Unlike the siderophores, all TBDTs have similar structures and belong to the outer membrane β-barrel protein superfamily. The way in which the siderophore-iron complex passes through the TBDT is still unclear. In some bacteria, TBDTs are also partners of signaling cascades regulating the expression of proteins involved in siderophore biosynthesis and siderophore-iron acquisition.
Collapse
Affiliation(s)
- Isabelle J Schalk
- UMR 7242, Université de Strasbourg-CNRS, ESBS, Boulevard Sébastien Brant, Strasbourg, France.
| | | | | |
Collapse
|
19
|
Pakchung AAH, Soe CZ, Lifa T, Codd R. Complexes formed in solution between vanadium(IV)/(V) and the cyclic dihydroxamic acid putrebactin or linear suberodihydroxamic acid. Inorg Chem 2011; 50:5978-89. [PMID: 21627146 PMCID: PMC3124108 DOI: 10.1021/ic1025119] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Indexed: 01/25/2023]
Abstract
An aerobic solution prepared from V(IV) and the cyclic dihydroxamic acid putrebactin (pbH(2)) in 1:1 H(2)O/CH(3)OH at pH = 2 turned from blue to orange and gave a signal in the positive ion electrospray ionization mass spectrometry (ESI-MS) at m/z(obs) 437.0 attributed to the monooxoV(V) species [V(V)O(pb)](+) ([C(16)H(26)N(4)O(7)V](+), m/z(calc) 437.3). A solution prepared as above gave a signal in the (51)V NMR spectrum at δ(V )= -443.3 ppm (VOCl(3), δ(V) = 0 ppm) and was electron paramagnetic resonance silent, consistent with the presence of [V(V)O(pb)](+). The formation of [V(V)O(pb)](+) was invariant of [V(IV)]:[pbH(2)] and of pH values over pH = 2-7. In contrast, an aerobic solution prepared from V(IV) and the linear dihydroxamic acid suberodihydroxamic acid (sbhaH(4)) in 1:1 H(2)O/CH(3)OH at pH values of 2, 5, or 7 gave multiple signals in the positive and negative ion ESI-MS, which were assigned to monomeric or dimeric V(V)- or V(IV)-sbhaH(4) complexes or mixed-valence V(V)/(IV)-sbhaH(4) complexes. The complexity of the V-sbhaH(4) system has been attributed to dimerization (2[V(V)O(sbhaH(2))](+) ↔ [(V(V)O)(2)(sbhaH(2))(2)](2+)), deprotonation ([V(V)O(sbhaH(2))](+) - H(+) ↔ [V(V)O(sbhaH)](0)), and oxidation ([V(IV)O(sbhaH(2))](0) -e(-) ↔ [V(V)O(sbhaH(2))](+)) phenomena and could be described as the sum of two pH-dependent vectors, the first comprising the deprotonation of hydroxamate (low pH) to hydroximate (high pH) and the second comprising the oxidation of V(IV) (low pH) to V(V) (high pH). Macrocyclic pbH(2) was preorganized to form [V(V)O(pb)](+), which would provide an entropy-based increase in its thermodynamic stability compared to V(V)-sbhaH(4) complexes. The half-wave potentials from solutions of [V(IV)]:[pbH(2)] (1:1) or [V(IV)]:[sbhaH(4)] (1:2) at pH = 2 were E(1/2) -335 or -352 mV, respectively, which differed from the expected trend (E(1/2) [VO(pb)](+/0) < V(V/IV)-sbhaH(4)). The complex solution speciation of the V(V)/(IV)-sbhaH(4) system prevented the determination of half-wave potentials for single species. The characterization of [V(V)O(pb)](+) expands the small family of documented V-siderophore complexes relevant to understanding V transport and assimilation in the biosphere.
Collapse
Affiliation(s)
- Amalie A. H. Pakchung
- Center for Heavy Metals Research, School of Chemistry and School of Medical Sciences (Pharmacology) and Bosch Institute, University of Sydney, New South Wales 2006, Australia
| | - Cho Zin Soe
- Center for Heavy Metals Research, School of Chemistry and School of Medical Sciences (Pharmacology) and Bosch Institute, University of Sydney, New South Wales 2006, Australia
| | - Tulip Lifa
- Center for Heavy Metals Research, School of Chemistry and School of Medical Sciences (Pharmacology) and Bosch Institute, University of Sydney, New South Wales 2006, Australia
| | - Rachel Codd
- Center for Heavy Metals Research, School of Chemistry and School of Medical Sciences (Pharmacology) and Bosch Institute, University of Sydney, New South Wales 2006, Australia
| |
Collapse
|
20
|
Bassanetti I, Gennari M, Marchiò L, Terenghi M, Elviri L. Li+, Cu+, and Ag+ Oligonuclear Structures with the Sterically Demanding Bis(3,5-tertbutylpyrazol-1-yl)dithioacetate Heteroscorpionate Ligand. Inorg Chem 2010; 49:7007-15. [DOI: 10.1021/ic100886x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Irene Bassanetti
- Dipartimento di Chimica Generale ed Inorganica, Chimica Analitica, Chimica Fisica, Università degli Studi di Parma, viale G. P. Usberti 17/a, I 43100 Parma, Italy
| | - Marcello Gennari
- Dipartimento di Chimica Generale ed Inorganica, Chimica Analitica, Chimica Fisica, Università degli Studi di Parma, viale G. P. Usberti 17/a, I 43100 Parma, Italy
| | - Luciano Marchiò
- Dipartimento di Chimica Generale ed Inorganica, Chimica Analitica, Chimica Fisica, Università degli Studi di Parma, viale G. P. Usberti 17/a, I 43100 Parma, Italy
| | - Mattia Terenghi
- Dipartimento di Chimica Generale ed Inorganica, Chimica Analitica, Chimica Fisica, Università degli Studi di Parma, viale G. P. Usberti 17/a, I 43100 Parma, Italy
| | - Lisa Elviri
- Dipartimento di Chimica Generale ed Inorganica, Chimica Analitica, Chimica Fisica, Università degli Studi di Parma, viale G. P. Usberti 17/a, I 43100 Parma, Italy
| |
Collapse
|
21
|
Crumbliss AL, Harrington JM. Iron sequestration by small molecules: Thermodynamic and kinetic studies of natural siderophores and synthetic model compounds. ADVANCES IN INORGANIC CHEMISTRY 2009. [DOI: 10.1016/s0898-8838(09)00204-9] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
|
22
|
Chen Z, Weber SG. Determination of binding constants by affinity capillary electrophoresis, electrospray ionization mass spectrometry and phase-distribution methods. Trends Analyt Chem 2008; 27:738-748. [PMID: 19802330 PMCID: PMC2600677 DOI: 10.1016/j.trac.2008.06.008] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Many methods for determining intermolecular interactions have been described in the literature in the past several decades. Chief among them are methods based on spectroscopic changes, particularly those based on absorption or nuclear magnetic resonance (NMR) [especially proton NMR ((1)H NMR)]. Recently, there have been put forward several new methods that are particularly adaptable, use very small quantities of material, and do not place severe requirements on the spectroscopic properties of the binding partners. This review covers new developments in affinity capillary electrophoresis, electrospray ionization mass spectrometry (ESI-MS) and phasetransfer methods.
Collapse
Affiliation(s)
- Zhi Chen
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Stephen G. Weber
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA
| |
Collapse
|
23
|
Kadi N, Song L, Challis GL. Bisucaberin biosynthesis: an adenylating domain of the BibC multi-enzyme catalyzes cyclodimerization of N-hydroxy-N-succinylcadaverine. Chem Commun (Camb) 2008:5119-21. [PMID: 18956041 DOI: 10.1039/b813029a] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The bisucaberin biosynthetic gene cluster has been identified in Vibrio salmonicida and a domain from within the BibC multienzyme encoded by the cluster has been shown to catalyse ATP-dependent dimerisation and macrocyclisation of N-hydroxy-N-succinylcadaverine to form bisucaberin.
Collapse
Affiliation(s)
- Nadia Kadi
- Department of Chemistry, University of Warwick, Coventry, UKCV4 7AL
| | | | | |
Collapse
|
24
|
|
25
|
Devanur LD, Neubert H, Hider RC. The Fenton Activity of Iron(III) in the Presence of Deferiprone. J Pharm Sci 2008; 97:1454-67. [PMID: 17724662 DOI: 10.1002/jps.21039] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Hydroxyl radical production from a range of clinically relevant iron chelators in the presence of hydrogen peroxide was measured using the deoxyribose oxidation assay. Hydroxyl radical production from an iron complex is dependent on whether the ligand is able to completely surround the iron, thereby preventing access of reductants to the coordinated iron cation. The partially coordinated [(deferiprone)(2)Fe(III)](+) complex is able to generate hydroxyl radicals in the presence of oxidants, whereas the fully coordinated [(deferiprone)(3)Fe(III)](0) complex is not. Hydroxyl radical production from iron(III)deferiprone complexes is dependent on the molar ratio of iron to deferiprone, which, in turn, affects the speciation of the complex. Mass spectrometry data have confirmed the presence of the [(deferiprone)(2)Fe(III)](+) complex in aqueous solution. Hydroxyl radical production from the [(deferiprone)(2)Fe(III)](+) complex is maximal in the presence of equimolar ascorbate and hydrogen peroxide and is abolished in the absence of hydrogen peroxide. Under biological conditions, any [(deferiprone)(2)Fe(III)](+) complex formed intracellularly will be rapidly reduced by ascorbate. The resulting unstable iron(II) complex will dissociate to hexa-aquo iron(II), a major component of the endogenous intracellular labile iron pool.
Collapse
Affiliation(s)
- Lakshmi D Devanur
- Division of Pharmaceutical Sciences, King's College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, UK.
| | | | | |
Collapse
|
26
|
Laglera LM, Battaglia G, van den Berg CMG. Determination of humic substances in natural waters by cathodic stripping voltammetry of their complexes with iron. Anal Chim Acta 2007; 599:58-66. [PMID: 17765064 DOI: 10.1016/j.aca.2007.07.059] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2007] [Revised: 07/12/2007] [Accepted: 07/23/2007] [Indexed: 10/23/2022]
Abstract
A new voltammetric method is presented for the measurement of humic substances (HS) in natural waters. The method is based on catalytic cathodic stripping voltammetry (CSV) and makes use of adsorptive properties of iron-HS complexes on the mercury drop electrode at natural pH. A fulvic acid standard (IHSS) was used to confirm the voltammetric response (peak potential and sensitivity) for the HS for natural water samples. Optimized conditions included the linear-sweep mode, deposition at -0.1 V, pH buffered at 8 and a scan rate of 50 mV s(-1). At a deposition time of 240 s in the presence of 10 nM iron and 30 mM bromate, the detection limit was 5 microg L(-1) HS in seawater, which could be lowered further by an increase in the bromate concentration, or in the adsorption time. The method was used to determine HS in the Irish Sea which were found to occur at levels between 60 and 600 microg L(-1). The new method is sufficiently sensitive to detect the low HS content in oceanic samples and has implications to the study of iron speciation.
Collapse
Affiliation(s)
- Luis M Laglera
- Department of Earth and Ocean Sciences, University of Liverpool, Liverpool L69 3GP, UK
| | | | | |
Collapse
|
27
|
Liu H, Håkansson K, Lee JY, Sherman DH. Collision-activated dissociation, infrared multiphoton dissociation, and electron capture dissociation of the Bacillus anthracis siderophore petrobactin and its metal ion complexes. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2007; 18:842-9. [PMID: 17331739 DOI: 10.1016/j.jasms.2007.01.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2006] [Revised: 01/08/2007] [Accepted: 01/09/2007] [Indexed: 05/14/2023]
Abstract
Siderophores are high-affinity iron-chelating ligands produced by microorganisms to scavenge vital Fe(3+) from the environment. Thus, siderophores constitute potential therapeutic targets and their structural determination is important for exploiting their therapeutic value. Here, the virulence-associated siderophore petrobactin from Bacillus anthracis was characterized with electron capture dissociation (ECD). Fragmentation of doubly protonated petrobactin was investigated and compared to sustained off-resonance irradiation collision-activated dissociation (SORI CAD) and infrared multiphoton dissociation (IRMPD) of both the singly and doubly protonated species. These experiments demonstrate that ECD provides additional information (complementary bond cleavages) on the structure of petrobactin compared to both SORI CAD and IRMPD. Furthermore, complexes of petrobactin with divalent (Ca(2+), Fe(2+), and Co(2+)) and trivalent (Fe(3+) and Ga(3+)) metal cations were also subjected to SORI CAD and ECD. Again, most structural information was obtained from the ECD spectra. However, significant differences were found in both SORI CAD and ECD of metal complexes, dependent on the nature of the metal ion. Intriguingly, unique behavior, consistent with a recently proposed solution-phase structure, was observed for the highly preferred Fe(3+)-petrobactin complex.
Collapse
Affiliation(s)
- Haichuan Liu
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, USA
| | | | | | | |
Collapse
|
28
|
Leslie AD, Daneshfar R, Volmer DA. Infrared multiphoton dissociation of the siderophore enterobactin and its Fe(III) complex. Influence of Fe(III) binding on dissociation kinetics and relative energetics. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2007; 18:632-41. [PMID: 17208008 DOI: 10.1016/j.jasms.2006.11.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2006] [Revised: 11/22/2006] [Accepted: 11/29/2006] [Indexed: 05/13/2023]
Abstract
The dissociation pathways of the siderophore enterobactin and its complex with Fe(III) were examined using infrared multiphoton dissociation (IRMPD). Under experimental conditions (pH = 3.5), both compounds' electrospray spectra exhibited exclusively singly-charged anions. The compositions of the dissociation products were characterized by accurate mass measurements using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). The primary dissociation channel for both species was determined to be the loss of one serine group from the precursor molecules. To further investigate the influence of Fe(III) binding on the intramolecular interactions, dissociation kinetics and relative energetics for the loss of this serine group were determined using the focused radiation for gaseous multiphoton energy-transfer (FRAGMENT) method. From the kinetic data, it was found that enterobactin was approximately seven times more reactive than its Fe(III) complex over the range of laser intensities investigated. The relative activation energies, however, exhibited similar values, approximately 7 kcal.mol(-1). These results suggest that at pH = 3.5, Fe(III) interacts with only two of the three serine groups. The results from the present work are believed to be valuable for the characterization of novel siderophores as well as their associated metabolites and synthetic analogues.
Collapse
Affiliation(s)
- Andrew D Leslie
- Institute for Marine Biosciences, Dalhousie University Halifax, Nova Scotia, Canada
| | | | | |
Collapse
|
29
|
Zawadzka AM, Vandecasteele FPJ, Crawford RL, Paszczynski AJ. Identification of siderophores ofPseudomonas stutzeri. Can J Microbiol 2006; 52:1164-76. [PMID: 17473886 DOI: 10.1139/w06-077] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have identified two types of siderophores produced by Pseudomonas, one of which has never before been found in the genus. Twelve strains of Pseudomonas stutzeri belonging to genomovars 1, 2, 3, 4, 5, and 9 produced proferrioxamines, the hydroxamate-type siderophores. Pseudomonas stutzeri JM 300 (genomovar 7) and DSM 50238 (genomovar 8) and Pseudomonas balearica DSM 6082 produced amonabactins, catecholate-type siderophores. The major proferrioxamines detected were the cyclic proferrioxamines E and D2. Pseudomonas stutzeri KC also produced cyclic (X1and X2) and linear (G1and G2a-c) proferrioxamines. Our data indicate that the catecholate-type siderophores belong to amonabactins P 750, P 693, T 789, and T 732. A mutant of P. stutzeri KC (strain CTN1) that no longer produced the secondary siderophore pyridine-2,6-dithiocarboxylic acid continued to produce all other siderophores in its normal spectrum. Siderophore profiles suggest that strain KC (genomovar 9) belongs to the proferrioxamine-producing P. stuzeri. Moreover, a putative ferrioxamine outer membrane receptor gene foxA was identified in strain KC, and colony hybridization showed the presence of homologous receptor genes in all P. stutzeri and P. balearica strains tested.Key words: siderophore, Pseudomonas stutzeri, ferrioxamine, amonabactin.
Collapse
Affiliation(s)
- Anna M Zawadzka
- Environmental Biotechnology Institute, University of Idaho, Moscow, ID 83844-1052, USA
| | | | | | | |
Collapse
|
30
|
Xuan Y, Scheuermann EB, Meda AR, Hayen H, von Wirén N, Weber G. Separation and identification of phytosiderophores and their metal complexes in plants by zwitterionic hydrophilic interaction liquid chromatography coupled to electrospray ionization mass spectrometry. J Chromatogr A 2006; 1136:73-81. [PMID: 17045280 DOI: 10.1016/j.chroma.2006.09.060] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2006] [Revised: 09/15/2006] [Accepted: 09/20/2006] [Indexed: 11/29/2022]
Abstract
A sensitive method for the separation of different phytosiderophores (PS) of the mugineic acid (MA) family, and the candidate ligand for intracellular metal transport in plants nicotianamine (NA), and respective metal complexes in plants by zwitterionic hydrophilic interaction liquid chromatography (ZIC-HILIC) coupled to electrospray ionization mass spectrometry (ESI-MS) is described. Separation of mugineic acid, 2'-deoxymugineic acid (DMA), 3-epi-hydroxymugineic acid (epi-HMA), nicotianamine, Fe(III)-DMA, Fe(III)-NA, M(II)-DMA, and M(II)-NA complexes (M(II)=Zn(II), Cu(II), Ni(II), and Fe(II)), was achieved within 22 min on the ZIC-HILIC column by using a gradient elution with a mobile phase consisting of ammonium acetate and acetonitrile at pH 7.3, at a flow rate of 0.15 mL/min. The on-line coupling to ESI-MS in the negative ionization mode enables the detection of these compounds in the micromol/L range, which is the relevant concentration range in real plant samples. DMA-complexes of Fe(III), Zn, and Cu in wheat root, and an NA-complex of Ni in Arabidopsis were detected and identified by the proposed method. Even in the case of partial coelution of some divalent metal complexes, the identification is possible by their distinct mass spectra. The stability of metal complexes during separation was checked by injecting ethylenediaminetetraacetic acid (EDTA) after each run of metal-phytosiderophore complexes. Good stability of divalent-phytosiderophores, except for Fe(II)-complexes, was observed. During gradient separation, Fe(III)-complexes are partly dissociated (<20%), but a good sensitivity of Fe(III)-DMA in real plant samples is still achieved. In order to avoid instability problems with the separation of Fe-complexes, an isocratic separation is proposed, which allows the separation of ferrous and ferric complexes in 2 min.
Collapse
Affiliation(s)
- Yue Xuan
- ISAS - Institute for Analytical Sciences, Bunsen-Kirchhoff-Strasse 11, D-44139 Dortmund, Germany
| | | | | | | | | | | |
Collapse
|
31
|
Storey EP, Boghozian R, Little JL, Lowman DW, Chakraborty R. Characterization of ‘Schizokinen’; a dihydroxamate-type siderophore produced by Rhizobium leguminosarum IARI 917. Biometals 2006; 19:637-49. [PMID: 16758117 DOI: 10.1007/s10534-006-9001-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2006] [Accepted: 02/07/2006] [Indexed: 11/29/2022]
Abstract
The Rhizobia comprise one of the most important groups of beneficial bacteria, which form nodules on the roots (rarely on the stems) of leguminous plants. They live within the nodules and reduce atmospheric nitrogen to ammonia, which is further assimilated by plants into required nitrogenous compounds. The Rhizobia in return obtain nutrition from the plant. Rhizobia are free-living soil bacteria and have to compete with other microorganisms for the limited available iron in the rhizosphere. In order to acquire iron Rhizobia have been shown to express siderophore-mediated iron transport systems. Rhizobium leguminosarum IARI 917 was investigated for its ability to produce siderophore. It was found to produce a dihydroxamate type siderophore under iron restricted conditions. The siderophore was purified and chemically characterized. The ESMS, MS/MS and NMR analysis indicate the dihydroxamate siderophore to be 'schizokinen', a siderophore reported to be produced by Bacillus megaterium that shares a similar structure to 'rhizobactin 1021' produced by Sinorhizobium meliloti 1021. This is the first report of production of schizokinen by a strain of R. leguminosarum, therefore it was carefully investigated to confirm that it is indeed 'schizokinen' and not a degradation product of 'rhizobactin 1021'. Since ferric-siderophore complexes are transported across the outer membrane (OM) into the periplasm via an OM receptor protein, R. leguminosarum IARI 917 was investigated for the presence of an OM receptor for 'ferric-schizokinen'. SDS PAGE analysis of whole cell pellet and extracted OM fractions indicate the presence of a possible iron-repressible OM receptor protein with the molecular weight (MW) of approximately 74 kDa.
Collapse
Affiliation(s)
- E P Storey
- Department of Health Sciences, College of Public and Allied Health, East Tennessee State University, 37614 Johnson City, TN, USA.
| | | | | | | | | |
Collapse
|
32
|
Hayen H, Volmer DA. Different iron-chelating properties of pyochelin diastereoisomers revealed by LC/MS. Anal Bioanal Chem 2006; 385:606-11. [PMID: 16715280 DOI: 10.1007/s00216-006-0443-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2006] [Revised: 03/15/2006] [Accepted: 03/17/2006] [Indexed: 11/26/2022]
Abstract
Pyochelin is a siderophore and virulence factor common to Burkholderia cepacia and several Pseudomonas strains. It is isolated from bacterial media as a mixture of two epimers, which readily equilibrate in most solvents. Experiments based on high-performance liquid chromatography/electrospray ionization mass spectrometry are reported here, allowing the investigation of the different Fe(III)-chelating properties of pyochelin diastereomers in solution without the need for labourious isolation. It is demonstrated in this study that only one of the two pyochelin diastereomers is able to chelate Fe(III); no Fe(III) complexes of the other diastereomer could be detected. The Fe(III)-pyochelin complex exhibited a 1:1 metal-to-siderophore ratio and no evidence for other stoichiometries was found.
Collapse
Affiliation(s)
- Heiko Hayen
- Institute for Analytical Sciences, Bunsen-Kirchhoff-Str. 11, 44139 Dortmund, Germany.
| | | |
Collapse
|
33
|
Di Marco VB, Bombi GG. Electrospray mass spectrometry (ESI-MS) in the study of metal-ligand solution equilibria. MASS SPECTROMETRY REVIEWS 2006; 25:347-79. [PMID: 16369936 DOI: 10.1002/mas.20070] [Citation(s) in RCA: 215] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
In the 20 years, since the introduction of electrospray mass spectrometry (ESI-MS), the use of this technique in various fields of inorganic, organometallic, and analytical chemistry has been steadily increasing. In this study, the application of ESI-MS to the study of metal-ligand solution equilibria is reviewed (till 2004 included). In a first section, advantages and drawbacks of ESI-MS in this type of application are described. Subsequently, a list of ca. 300 studies is reported, in which ESI-MS was used to give number and stoichiometry of the species at equilibrium, or also to estimate their stability constants. All studies are classified according to the metal ions under examination. Other related applications, such as host-guest interactions and metal ion-protein binding studies, are briefly reviewed as well.
Collapse
|
34
|
Weber G, von Wirén N, Hayen H. Analysis of iron(II)/iron(III) phytosiderophore complexes by nano-electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2006; 20:973-80. [PMID: 16479550 DOI: 10.1002/rcm.2402] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Nano-electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (nano-ESI-FTICRMS) was employed for the analysis of the phytosiderophore 2'-deoxymugineic acid (DMA) and the candidate ligand for the intracellular iron transport in plants nicotianamine (NA). Due to the zwitterionic nature of NA and DMA, complementary mass spectra were obtained in positive and negative ionization modes. The technique was also used for speciation of their complexes with Fe(II) and Fe(III), respectively. The species observed at pH 7.3 are the 1:1 Fe-ligand complexes and no evidence for the existence of dimeric complexes was observed. NA and DMA differ only by one mass unit. Consequently, in the system NA + DMA + Fe(II)/Fe(III), there are pairs of iron species (i.e. NA-Fe(II) and DMA-Fe(III)) with the same nominal mass, which differ only by approximately 0.02 mass units. It is shown that high-resolution MS accompanied by accurate mass data analysis allows the unequivocal identification of all four iron species (NA-Fe(II), NA-Fe(III), DMA-Fe(II), DMA-Fe(III)) in one solution without separation. We also addressed the possible alteration of the oxidation state of chelated iron under nano-ESI conditions, but no redox reactions were observed under optimized conditions.
Collapse
Affiliation(s)
- Günther Weber
- Institute for Analytical Sciences, Bunsen-Kirchhoff-Str. 11, D-44139 Dortmund, Germany
| | | | | |
Collapse
|
35
|
Zou G, Boyer GL. Synthesis and properties of different metal complexes of the siderophore desferriferricrocin. Biometals 2005; 18:63-74. [PMID: 15865411 DOI: 10.1007/s10534-004-5786-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Desferriferricrocin is a cyclic hexa-peptide siderophore with three hydroxamates as primary coordination groups. It forms metal complexes with Fe(III), Cr(III), Al(III), Ga(III), Cu(II), and Zn(II). These complexes were prepared and characterized using UV-vis, circular dichroism spectroscopy (CD), nuclear magnetic resonance spectroscopy (NMR), and electrospray ionization mass spectroscopy (ESI-MS). The mononuclear trivalent metal complexes of desferriferricrocin were stable in aqueous solutions, and their coordination centers primarily adopted the lambda configuration. The formation of multinuclear complexes of desferriferricrocin was determined by ESI-MS. Desferriferricrocin was able to bind up to three Cu(II) and two Zn(II) respectively. Heteronuclear complexes containing one trivalent and one divalent were also determined. In these complexes, amide nitrogens were utilized as alternative binding groups of desferriferricrocin in addition to the primary binding groups, the hydroxamates.
Collapse
Affiliation(s)
- Guozhang Zou
- Department of Chemistry, State University of New York, College of Environmental Science and Forestry, Syracuse, New York 13210, USA
| | | |
Collapse
|
36
|
Sudhir PR, Wu HF, Zhou ZC. Probing the interaction of kojic acid antibiotics with iron(III) chloride by using electrospray tandem mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2005; 19:209-212. [PMID: 15593254 DOI: 10.1002/rcm.1773] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Kojic acid, 5-hydroxy-2-(hydroxymethyl)-4H-pyran-4-one, has been used extensively as a clinical iron-chelating drug although the nature of the complexes of iron and kojic acid has not been established. In this article we demonstrate the complexation of kojic acid with iron(III) chloride by using electrospray ionization mass spectrometry (ESI-MS). The ESI-MS analysis revealed different reactions between iron(III) chloride and kojic acid (M), and the mass spectrum exhibited four complexes: [Fe+2(M-H)]+, [Fe+3(M-H)+H]+, [Fe2+4(M-H)+Cl]+, and [Fe2+5(M-H)]+. All these proposed complexes and the presence of chloride ion in one of the dinuclear complexes have been confirmed by isotopic patterns and fragmentation studies by means of tandem mass spectrometry (MSn).
Collapse
Affiliation(s)
- Putty-Reddy Sudhir
- Graduate Institute of Life Sciences, Tamkang University, Tamsui, 251, Taiwan
| | | | | |
Collapse
|
37
|
Budimir N, Fournier F, Bailly T, Burgada R, Tabet JC. Study of metal complexes of a tripodal hydroxypyridinone ligand by electrospray tandem mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2005; 19:1822-8. [PMID: 15945021 DOI: 10.1002/rcm.1993] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The tripodal ligand N,N,N-tris[(1,hydroxy-2-pyridinon-6-yl)amide]propylamine was synthesized. It is composed of an anchor (nitrogen atom), a functional group (hydroxamate), and also a spacer of variable length defined by the number of methylene groups linking the anchor and the functional group. The characterization of this ligand in the presence of several divalent metal cations (Fe(II), Mn(II), Co(II) and Cu(II)), performed by electrospray ionization mass spectrometry (ESI-MS and ESI-MS/MS), allowed elucidation of oxidation states and also of different fragmentation patterns. The importance of the spacer length was studied in the case of the iron binary complex by comparing this ligand with another with a shorter spacer. In this way the stabilizing conditions, in which hydrogen bonds are implicated, were clarified.
Collapse
Affiliation(s)
- Natali Budimir
- Equipe de Spectrométrie de masse (LCSOB) UMR 7613 CNRS (Synthèse, Structure et Fonction de Molécules Bioactives), B45, Université Pierre et Marie Curie, 4 place Jussieu, 75252 Paris Cedex 05, France
| | | | | | | | | |
Collapse
|
38
|
Farkas E, Buglyó P, Enyedy ÉA, Amelia Santos M. Factors affecting the metal ion–hydroxamate interactions II: effect of the length of the connecting chain on the Fe(III), Mo(VI) and V(V) complexation of some new desferrioxamine B (DFB) model dihydroxamic acids. Inorganica Chim Acta 2004. [DOI: 10.1016/j.ica.2004.02.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
39
|
Farkas E, Bátka D, Pataki Z, Buglyó P, Santos MA. Interaction of desferrioxamine B (DFB) model dihydroxamic acids with some essential and toxic metal(ii) ions: effects of the structure and length of connecting chains on the metal ion selectivity. Dalton Trans 2004:1248-53. [PMID: 15252668 DOI: 10.1039/b401426j] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Complexation of desferrioxamine B (DFB) model dihydroxamic acids (HO(CH3)NCO(CH2)xCONH(CH2)yCON(CH3)OH where x = 2, 3, y = 5, 4, 3, 2, and the compounds are abbreviated as 2,5-DIHA, 2,4-DIHA, 2,3-DIHA, 2,2-DIHA, 3,4-DIHA and 3,3-DIHA, respectively) with Cu(II), Ni(II), Zn(II), Pb(II) and Cd(II) was studied by pH-potentiometric and spectroscopic (UV-VIS, NMR and ESI-MS) techniques. The effects of the position of the peptide group, the chain length and the geometry on the stability and stoichiometry of the complexes formed were evaluated. It was concluded that metal ions preferring regular octahedral geometry in their complexes form the most stable bis-chelated mononuclear complexes, [ML], with 2,5-DIHA having the same connecting chain structure and length as those of DFB. This benefit of 2,5-DIHA, however, almost disappears in the case of Cu(II). With this metal, which prefers the equatorial coordination of two hydroxamates, the parallel formation of both [CuL] and [Cu2L2] was found. ESI-MS results indicate that the latter complex is exclusively formed with 2,2-DIHA involving the shortest linker. All these dihydroxamic acids are excellent chelating agents for Pb(II). The special geometry determined by the lone pair electrons should be responsible for the somewhat unique preference order of the ligands towards the Pb(II) ion, for the favoured formation of the monomeric bis-chelated complexes and also for the unexpectedly high stability of the species [Pb(2,2-DIHA)].
Collapse
Affiliation(s)
- Etelka Farkas
- Department of Inorganic and Analytical Chemistry, University of Debrecen, H-4010, Debrecen, Hungary
| | | | | | | | | |
Collapse
|
40
|
Tsierkezos NG, Schröder D, Schwarz H. Gas-Phase Solvation Behavior of Ni(II) in Water/N,N-Dimethylformamide Mixtures. J Phys Chem A 2003. [DOI: 10.1021/jp0358073] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Nikos G. Tsierkezos
- Institut für Chemie der Technischen Universität Berlin, Strasse des 17. Juni 135, D-10623 Berlin, Germany
| | - Detlef Schröder
- Institut für Chemie der Technischen Universität Berlin, Strasse des 17. Juni 135, D-10623 Berlin, Germany
| | - Helmut Schwarz
- Institut für Chemie der Technischen Universität Berlin, Strasse des 17. Juni 135, D-10623 Berlin, Germany
| |
Collapse
|
41
|
Rosenberg E. The potential of organic (electrospray- and atmospheric pressure chemical ionisation) mass spectrometric techniques coupled to liquid-phase separation for speciation analysis. J Chromatogr A 2003; 1000:841-89. [PMID: 12877203 DOI: 10.1016/s0021-9673(03)00603-4] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The use of mass spectrometry based on atmospheric pressure ionisation techniques (atmospheric pressure chemical ionisation, APCI, and electrospray ionisation, ESI) for speciation analysis is reviewed with emphasis on the literature published in and after 1999. This report accounts for the increasing interest that atmospheric pressure ionisation techniques, and in particular ESI, have found in the past years for qualitative and quantitative speciation analysis. In contrast to element-selective detectors, organic mass spectrometric techniques provide information on the intact metal species which can be used for the identification of unknown species (particularly with MS-MS detection) or the confirmation of the actual presence of species in a given sample. Due to the complexity of real samples, it is inevitable in all but the simplest cases to couple atmospheric pressure MS detection to a separation technique. Separation in the liquid phase (capillary electrophoresis or liquid chromatography in reversed phase, ion chromatographic or size-exclusion mode) is particularly suitable since the available techniques cover a very wide range of analyte polarities and molecular mass. Moreover, derivatisation can normally be avoided in liquid-phase separation. Particularly in complex environmental or biological samples, separation in one dimension is not sufficient for obtaining adequate resolution for all relevant species. In this case, multi-dimensional separation, based on orthogonal separation techniques, has proven successful. ESI-MS is also often used in parallel with inductively coupled plasma MS detection. This review is structured in two parts. In the first, the fundamentals of atmospheric pressure ionisation techniques are briefly reviewed. The second part of the review discusses recent applications including redox species, use of ESI-MS for structural elucidation of metal complexes, characterisation and quantification of small organometallic species with relevance to environment, health and food. Particular attention is given to the characterisation of biomolecules and metalloproteins (metallothioneins and phytochelatins) and to the investigation of the interaction of metals and biomolecules. Particularly in the latter field, ESI-MS is the ideal technique due to the softness of the ionisation process which allows to assume that the detected gas-phase ions are a true representation of the ions or ion-biomolecule complexes prevalent in solution. It is particularly this field, important to biochemistry, physiology and medical chemistry, where we can expect significant developments also in the future.
Collapse
Affiliation(s)
- Erwin Rosenberg
- Vienna University of Technology, Institute of Chemical Technology and Analytics, Getreidemarkt 91164 AC, A-1060 Vienna, Austria.
| |
Collapse
|
42
|
Di Marco VB, Bombi GG, Tubaro M, Traldi P. Electrospray ionization mass spectrometry in studies of aluminium(III)-ligand solution equilibria. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2003; 17:2039-2046. [PMID: 12955732 DOI: 10.1002/rcm.1147] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Electrospray ionization mass spectrometry (ESI-MS) has been applied to the study of solution equilibria between Al(III) and the two ligands 4-hydroxy-3-pyridinecarboxylic acid (4H3P) and 3-hydroxy-4-pyridinecarboxylic acid (3H4P). The results compare well with the speciation data obtained from potentiometric, UV-visible spectroscopy, and NMR measurements. This agreement suggests the applicability of ES-MS to the study of more complicated aluminium-ligand systems.
Collapse
Affiliation(s)
- Valerio B Di Marco
- Università degli Studi di Padova, Dipartimento di Chimica Inorganica, Metallorganica ed Analitica, via Marzolo 1, 35131 Padova, Italy
| | | | | | | |
Collapse
|
43
|
Boukhalfa H, Crumbliss AL. Kinetics and mechanism of a catalytic chloride ion effect on the dissociation of model siderophore hydroxamate-iron(III) complexes. Inorg Chem 2001; 40:4183-90. [PMID: 11487321 DOI: 10.1021/ic010050k] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Proton-driven ligand dissociation kinetics in the presence of chloride, bromide, and nitrate ions have been investigated for model siderophore complexes of Fe(III) with the mono- and dihydroxamic acid ligands R(1)C(=O)N(OH)R(2) (R(1) = CH(3), R(2) = H; R(1) = CH(3), R(2) = CH(3); R(1) = C(6)H(5), R(2) = H; R(1) = C(6)H(5), R(2) = C(6)H(5)) and CH(3)N(OH)C(=O)[CH(2)](n)C(=O)N(OH)CH(3) (H(2)L(n); n = 2, 4, 6). Significant rate acceleration in the presence of chloride ion is observed for ligand dissociation from the bis(hydroxamate)- and mono(hydroxamate)-bound complexes. Rate acceleration was also observed in the presence of bromide and nitrate ions but to a lesser extent. A mechanism for chloride ion catalysis of ligand dissociation is proposed which involves chloride ion dependent parallel paths with transient Cl(-) coordination to Fe(III). The labilizing effect of Cl(-) results in an increase in microscopic rate constants on the order of 10(2)-10(3). Second-order rate constants for the proton driven dissociation of dinuclear Fe(III) complexes formed with H(2)L(n)() were found to vary with Fe-Fe distance. An analysis of these data permits us to propose a reactive intermediate of the structure (H(2)O)(4)Fe(L(n)())Fe(HL(n))(Cl)(OH(2))(2+) for the chloride ion dependent ligand dissociation path. Environmental and biological implications of chloride ion enhancement of Fe(III)-ligand dissociation reactions are presented.
Collapse
Affiliation(s)
- H Boukhalfa
- Department of Chemistry, Duke University, Box 90346, Durham, North Carolina 27708-0346, USA
| | | |
Collapse
|
44
|
Current literature in mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2001; 36:446-457. [PMID: 11333450 DOI: 10.1002/jms.91] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
|