851
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Sun H, Chai ZF. Metallomics: An integrated science for metals in biology and medicine. ACTA ACUST UNITED AC 2010. [DOI: 10.1039/b920672h] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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852
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Nutritional immunity beyond iron: a role for manganese and zinc. Curr Opin Chem Biol 2009; 14:218-24. [PMID: 20015678 DOI: 10.1016/j.cbpa.2009.11.008] [Citation(s) in RCA: 445] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2009] [Revised: 11/05/2009] [Accepted: 11/06/2009] [Indexed: 12/14/2022]
Abstract
Vertebrates sequester iron from invading pathogens, and conversely, pathogens express a variety of factors to steal iron from the host. Recent work has demonstrated that in addition to iron, vertebrates sequester zinc and manganese both intracellularly and extracellularly to protect against infection. Intracellularly, vertebrates utilize the ZIP/ZnT families of transporters to manipulate zinc levels, as well as Nramp1 to manipulate manganese levels. Extracellularly, the S100 protein calprotectin sequesters manganese and potentially zinc to inhibit microbial growth. To circumvent these defenses, bacteria possess high affinity transporters to import specific nutrient metals. Limiting the availability of zinc and manganese as a mechanism to defend against infection expands the spectrum of nutritional immunity and further establishes metal sequestration as a key defense against microbial invaders.
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853
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Jahromi EZ, Gailer J. Probing bioinorganic chemistry processes in the bloodstream to gain new insights into the origin of human diseases. Dalton Trans 2009:329-36. [PMID: 20023963 DOI: 10.1039/b912941n] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
In the context of elucidating the origin of human diseases, past poisoning epidemics have revealed that exceedingly small doses of inorganic environmental pollutants can result in dramatic effects on human health. Today, numerous organic and inorganic pollutants have been quantified in human blood, but the interpretation of these concentrations remains--from a public health point of view--problematic. Conversely, the biomolecular origin for several grievous human diseases is essentially unknown. Taken together and viewed in the context of recent bioinorganic research findings, the established human blood concentrations of toxic metals and metalloids may be functionally connected with the etiology of specific human diseases. To unravel the underlying biomolecular mechanisms, and taking into account the basic flow of dietary matter through mammalian organisms, a better understanding of the bioinorganic chemistry of toxic metals and metalloid compounds in the bloodstream is emerging as a promising avenue for future research. To this end, the concerted application of modern proteomic methodologies, synchrotron-based X-ray absorption spectroscopy and established spectroscopic techniques will contribute to better define the role that blood-based bioinorganic chemistry-related processes play in the origin of human diseases. The application of this and other modern proteomic methodologies could contribute to a better understanding of the role that blood-based bioinorganic chemistry-related processes play in the origin and etiology of human diseases.
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Affiliation(s)
- Elham Zeini Jahromi
- Department of Chemistry and BSc Environmental Science Program, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada
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854
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Stoll KE, Draper WE, Kliegman JI, Golynskiy MV, Brew-Appiah RAT, Phillips RK, Brown HK, Breyer WA, Jakubovics NS, Jenkinson HF, Brennan RG, Cohen SM, Glasfeld A. Characterization and structure of the manganese-responsive transcriptional regulator ScaR. Biochemistry 2009; 48:10308-20. [PMID: 19795834 PMCID: PMC3586275 DOI: 10.1021/bi900980g] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The streptococcal coaggregation regulator (ScaR) of Streptococcus gordonii is a manganese-dependent transcriptional regulator. When intracellular manganese concentrations become elevated, ScaR represses transcription of the scaCBA operon, which encodes a manganese uptake transporter. A member of the DtxR/MntR family of metalloregulators, ScaR shares sequence similarity with other family members, and many metal-binding residues are conserved. Here, we show that ScaR is an active dimer, with two dimers binding the 46 base pair scaC operator. Each ScaR subunit binds two manganese ions, and the protein is activated by a variety of other metal ions, including Cd(2+), Co(2+), and Ni(2+) but not Zn(2+). The crystal structure of apo-ScaR reveals a tertiary and quaternary structure similar to its homologue, the iron-responsive regulator DtxR. While each DtxR subunit binds a metal ion in two sites, labeled primary and ancillary, crystal structures of ScaR determined in the presence of Cd(2+) and Zn(2+) show only a single occupied metal-binding site that is novel to ScaR. The site analogous to the primary site in DtxR is unoccupied, and the ancillary site is absent from ScaR. Instead, metal ions bind to ScaR at a site labeled "secondary", which is composed of Glu80, Cys123, His125, and Asp160 and lies roughly 5 A away from where the ancillary site would be predicted to exist. This difference suggests that ScaR and its closely related homologues are activated by a mechanism distinct from that of either DtxR or MntR.
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Affiliation(s)
- Kate E. Stoll
- Department of Chemistry, Reed College, Portland, Oregon 97202
| | | | - Joseph I. Kliegman
- Department of Chemistry, Reed College, Portland, Oregon 97202
- Department of Chemistry and Biochemistry, University of California at San Diego, La Jolla, California 92093-0358
| | - Misha V. Golynskiy
- Department of Chemistry and Biochemistry, University of California at San Diego, La Jolla, California 92093-0358
| | | | - Rebecca K. Phillips
- Department of Chemistry, Reed College, Portland, Oregon 97202
- Department of Biochemistry and Molecular Biology, U. T. M. D. Anderson Cancer Center, Unit 1000 Houston, TX 77030
| | - Hattie K. Brown
- Department of Chemistry, Reed College, Portland, Oregon 97202
| | - Wendy A. Breyer
- Department of Chemistry, Reed College, Portland, Oregon 97202
| | | | - Howard F. Jenkinson
- Department of Oral and Dental Science, University of Bristol, Bristol BS1 2LY, UK
| | - Richard G. Brennan
- Department of Biochemistry and Molecular Biology, U. T. M. D. Anderson Cancer Center, Unit 1000 Houston, TX 77030
| | - Seth M. Cohen
- Department of Chemistry and Biochemistry, University of California at San Diego, La Jolla, California 92093-0358
| | - Arthur Glasfeld
- Department of Chemistry, Reed College, Portland, Oregon 97202
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855
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McRae R, Lai B, Fahrni CJ. Copper redistribution in Atox1-deficient mouse fibroblast cells. J Biol Inorg Chem 2009; 15:99-105. [PMID: 19865834 DOI: 10.1007/s00775-009-0598-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2009] [Accepted: 10/09/2009] [Indexed: 12/11/2022]
Abstract
Quantitative synchrotron X-ray fluorescence (SXRF) imaging of adherent mouse fibroblast cells deficient in antioxidant-1 (Atox1), a metallochaperone protein responsible for delivering Cu to cuproenzymes in the trans-Golgi network, revealed striking differences in the subcellular Cu distribution compared with wild-type cells. Whereas the latter showed a pronounced perinuclear localization of Cu, the Atox1-deficient cells displayed a mostly unstructured and diffuse distribution throughout the entire cell body. Comparison of the SXRF elemental maps for Zn and Fe of the same samples showed no marked differences between the two cell lines. The data underscore the importance of Atox1, not only as a metallochaperone for delivering Cu to cuproenzymes, but also as a key player in maintaining the proper distribution and organization of Cu at the cellular level.
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Affiliation(s)
- Reagan McRae
- Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, 30332, USA
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