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  1. Article ; Online: Gram-positive siderophore-shuttle with iron-exchange from Fe-siderophore to apo-siderophore by Bacillus cereus YxeB.

    Fukushima, Tatsuya / Allred, Benjamin E / Sia, Allyson K / Nichiporuk, Rita / Andersen, Ulla N / Raymond, Kenneth N

    Proceedings of the National Academy of Sciences of the United States of America

    2013  Volume 110, Issue 34, Page(s) 13821–13826

    Abstract: Small molecule iron-chelators, siderophores, are very important in facilitating the acquisition of Fe(III), an essential element for pathogenic bacteria. Many Gram-negative outer-membrane transporters and Gram-positive lipoprotein siderophore-binding ... ...

    Abstract Small molecule iron-chelators, siderophores, are very important in facilitating the acquisition of Fe(III), an essential element for pathogenic bacteria. Many Gram-negative outer-membrane transporters and Gram-positive lipoprotein siderophore-binding proteins have been characterized, and the binding ability of outer-membrane transporters and siderophore-binding proteins for Fe-siderophores has been determined. However, there is little information regarding the binding ability of these proteins for apo-siderophores, the iron-free chelators. Here we report that Bacillus cereus YxeB facilitates iron-exchange from Fe-siderophore to apo-siderophore bound to the protein, the first Gram-positive siderophore-shuttle system. YxeB binds ferrioxamine B (FO, Fe-siderophore)/desferrioxamine B (DFO, apo-siderophore) in vitro. Disc-diffusion assays and growth assays using the yxeB mutant reveal that YxeB is responsible for importing the FO. Cr-DFO (a FO analog) is bound by YxeB in vitro and B. cereus imports or binds Cr-DFO in vivo. In vivo uptake assays using Cr-DFO and FO and growth assays using DFO and Cr-DFO show that B. cereus selectively imports and uses FO when DFO is present. Moreover, in vitro competition assays using Cr-DFO and FO clearly demonstrate that YxeB binds only FO, not Cr-DFO, when DFO is bound to the protein. Iron-exchange from FO to DFO bound to YxeB must occur when DFO is initially bound by YxeB. Because the metal exchange rate is generally first order in replacement ligand concentration, protein binding of the apo-siderophore acts to dramatically enhance the iron exchange rate, a key component of the Gram-positive siderophore-shuttle mechanism.
    MeSH term(s) Bacillus cereus/metabolism ; Bacterial Proteins/genetics ; Bacterial Proteins/metabolism ; Binding, Competitive ; Biological Transport/physiology ; Chromatography, High Pressure Liquid ; Deferoxamine/metabolism ; Disk Diffusion Antimicrobial Tests ; Ferric Compounds/metabolism ; Fluorescence ; Mass Spectrometry ; Plasmids/genetics ; Protein Binding ; Regression Analysis ; Siderophores/metabolism
    Chemical Substances Bacterial Proteins ; Ferric Compounds ; Siderophores ; ferrioxamine B (4A0UG9NR9K) ; Deferoxamine (J06Y7MXW4D)
    Language English
    Publishing date 2013-08-07
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 209104-5
    ISSN 1091-6490 ; 0027-8424
    ISSN (online) 1091-6490
    ISSN 0027-8424
    DOI 10.1073/pnas.1304235110
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Facile, large-scale synthesis of dodecanethiol-stabilized Au38 clusters.

    Qian, Huifeng / Zhu, Manzhou / Andersen, Ulla N / Jin, Rongchao

    The journal of physical chemistry. A

    2008  Volume 113, Issue 16, Page(s) 4281–4284

    Abstract: It has long been a major challenge to achieve synthetic control over size and monodispersity of gold thiolate nanoclusters. Among the reported Aun thiolate clusters, Au38 has been shown to be particularly stable but was only obtained as a minor product ... ...

    Abstract It has long been a major challenge to achieve synthetic control over size and monodispersity of gold thiolate nanoclusters. Among the reported Aun thiolate clusters, Au38 has been shown to be particularly stable but was only obtained as a minor product in previous syntheses. In this work, we report a bulk solution synthetic method that permits large-scale, facile synthesis of truly monodisperse Au38 nanoclusters. This new method explores a two-phase ligand exchange process utilizing glutathione-capped Aun clusters as the starting material. The ligand exchange process with neat dodecanethiols causes gold core etching and secondary growth of clusters, and eventually leads to monodisperse Au38 clusters in high purity, which eliminates nontrivial postsynthetic separation steps. This method can be readily scaled up to synthesize Au38(SC12H25)24 in large quantities and thus makes the approach and Au38 nanoclusters of broad utility.
    MeSH term(s) Gold/chemistry ; Magnetic Resonance Spectroscopy ; Mass Spectrometry ; Nanostructures/chemistry ; Organometallic Compounds/chemical synthesis ; Organometallic Compounds/chemistry ; Spectrophotometry, Ultraviolet ; Sulfhydryl Compounds/chemistry ; Thermogravimetry
    Chemical Substances Organometallic Compounds ; Sulfhydryl Compounds ; dodecylmercaptan (112-55-0) ; Gold (7440-57-5)
    Language English
    Publishing date 2008-12-01
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, U.S. Gov't, Non-P.H.S.
    ISSN 1520-5215
    ISSN (online) 1520-5215
    DOI 10.1021/jp810893w
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Siderophore-mediated iron acquisition systems in Bacillus cereus: Identification of receptors for anthrax virulence-associated petrobactin .

    Zawadzka, Anna M / Abergel, Rebecca J / Nichiporuk, Rita / Andersen, Ulla N / Raymond, Kenneth N

    Biochemistry

    2009  Volume 48, Issue 16, Page(s) 3645–3657

    Abstract: During growth under iron limitation, Bacillus cereus and Bacillus anthracis, two human pathogens from the Bacillus cereus group of Gram-positive bacteria, secrete two siderophores, bacillibactin (BB) and petrobactin (PB), for iron acquisition via ... ...

    Abstract During growth under iron limitation, Bacillus cereus and Bacillus anthracis, two human pathogens from the Bacillus cereus group of Gram-positive bacteria, secrete two siderophores, bacillibactin (BB) and petrobactin (PB), for iron acquisition via membrane-associated substrate-binding proteins (SBPs) and other ABC transporter components. Since PB is associated with virulence traits in B. anthracis, the PB-mediated iron uptake system presents a potential target for antimicrobial therapies; its characterization in B. cereus is described here. Separate transporters for BB, PB, and several xenosiderophores are suggested by (55)Fe-siderophore uptake studies. The PB precursor, 3,4-dihydroxybenzoic acid (3,4-DHB), and the photoproduct of FePB (FePB(nu)) also mediate iron delivery into iron-deprived cells. Putative SBPs were recombinantly expressed, and their ligand specificity and binding affinity were assessed using fluorescence spectroscopy. The noncovalent complexes of the SBPs with their respective siderophores were characterized using ESI-MS. The differences between solution phase behavior and gas phase measurements are indicative of noncovalent interactions between the siderophores and the binding sites of their respective SBPs. These studies combined with bioinformatics sequence comparison identify SBPs from five putative transporters specific for BB and enterobactin (FeuA), 3,4-DHB and PB (FatB), PB (FpuA), schizokinen (YfiY), and desferrioxamine and ferrichrome (YxeB). The two PB receptors show different substrate ranges: FatB has the highest affinity for ferric 3,4-DHB, iron-free PB, FePB, and FePB(nu), whereas FpuA is specific to only apo- and ferric PB. The biochemical characterization of these SBPs provides the first identification of the transporter candidates that most likely play a role in the B. cereus group pathogenicity.
    MeSH term(s) Bacillus anthracis/metabolism ; Bacillus anthracis/pathogenicity ; Bacillus cereus/genetics ; Bacillus cereus/metabolism ; Bacterial Proteins/genetics ; Bacterial Proteins/metabolism ; Base Sequence ; Benzamides/chemistry ; Benzamides/metabolism ; Humans ; Iron/metabolism ; Molecular Sequence Data ; Molecular Structure ; Receptors, Cell Surface/genetics ; Receptors, Cell Surface/metabolism ; Recombinant Proteins/genetics ; Recombinant Proteins/metabolism ; Siderophores/chemistry ; Siderophores/genetics ; Siderophores/metabolism
    Chemical Substances Bacterial Proteins ; Benzamides ; Receptors, Cell Surface ; Recombinant Proteins ; Siderophores ; petrobactin ; Iron (E1UOL152H7)
    Language English
    Publishing date 2009-02-27
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 1108-3
    ISSN 1520-4995 ; 0006-2960
    ISSN (online) 1520-4995
    ISSN 0006-2960
    DOI 10.1021/bi8018674
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Bacillus cereus iron uptake protein fishes out an unstable ferric citrate trimer.

    Fukushima, Tatsuya / Sia, Allyson K / Allred, Benjamin E / Nichiporuk, Rita / Zhou, Zhongrui / Andersen, Ulla N / Raymond, Kenneth N

    Proceedings of the National Academy of Sciences of the United States of America

    2012  Volume 109, Issue 42, Page(s) 16829–16834

    Abstract: Citrate is a common biomolecule that chelates Fe(III). Many bacteria and plants use ferric citrate to fulfill their nutritional requirement for iron. Only the Escherichia coli ferric citrate outer-membrane transport protein FecA has been characterized; ... ...

    Abstract Citrate is a common biomolecule that chelates Fe(III). Many bacteria and plants use ferric citrate to fulfill their nutritional requirement for iron. Only the Escherichia coli ferric citrate outer-membrane transport protein FecA has been characterized; little is known about other ferric citrate-binding proteins. Here we report a unique siderophore-binding protein from the gram-positive pathogenic bacterium Bacillus cereus that binds multinuclear ferric citrate complexes. We have demonstrated that B. cereus ATCC 14579 takes up (55)Fe radiolabeled ferric citrate and that a protein, BC_3466 [renamed FctC (ferric citrate-binding protein C)], binds ferric citrate. The dissociation constant (K(d)) of FctC at pH 7.4 with ferric citrate (molar ratio 1:50) is 2.6 nM. This is the tightest binding observed of any B. cereus siderophore-binding protein. Nano electrospray ionization-mass spectrometry (nano ESI-MS) analysis of FctC and ferric citrate complexes or citrate alone show that FctC binds diferric di-citrate, and triferric tricitrate, but does not bind ferric di-citrate, ferric monocitrate, or citrate alone. Significantly, the protein selectively binds triferric tricitrate even though this species is naturally present at very low equilibrium concentrations.
    MeSH term(s) Bacillus cereus/metabolism ; Bacterial Proteins/metabolism ; Ferric Compounds/metabolism ; Ferric Compounds/pharmacokinetics ; Iron Radioisotopes/pharmacokinetics ; Isotope Labeling ; Mass Spectrometry ; Molecular Structure ; Protein Binding ; Siderophores/metabolism
    Chemical Substances Bacterial Proteins ; Ferric Compounds ; Iron Radioisotopes ; Siderophores ; ferric citrate (63G354M39Z)
    Language English
    Publishing date 2012-10-01
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 209104-5
    ISSN 1091-6490 ; 0027-8424
    ISSN (online) 1091-6490
    ISSN 0027-8424
    DOI 10.1073/pnas.1210131109
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article: Characterization of self-assembled supramolecular [Ga4L6] host-guest complexes by electrospray ionization mass spectrometry.

    Andersen, Ulla N / Seeber, Georg / Fiedler, Dorothea / Raymond, Kenneth N / Lin, Dayin / Harris, Don

    Journal of the American Society for Mass Spectrometry

    2006  Volume 17, Issue 3, Page(s) 292–296

    Abstract: Self-assembled supramolecular host-guest complexes have been characterized by electrospray ionization mass spectrometry. The spectra obtained by use of a Q-TOF instrument equipped with a Z-spray ion source show primarily the 3- and 4- charge states of ... ...

    Abstract Self-assembled supramolecular host-guest complexes have been characterized by electrospray ionization mass spectrometry. The spectra obtained by use of a Q-TOF instrument equipped with a Z-spray ion source show primarily the 3- and 4- charge states of the assemblies. The assemblies have the general formula [guest subset Ga4L6]11- where L represents the chelating bidentate catechol ligand 1,5-bis(2',3'-dihydroxy-benzamido)naphthalene and guests are tetramethyl ammonium (Me4N+), tetraethyl ammonium (Et4N+), tetra-n-propyl ammonium (Pr4N+) and decamethylcobaltocenium (Cp*2Co+) cations. For the first time, the mass spectrum of the empty assembly [Ga4L6]12- is reported. This article also reports that provided the electrospray ion source is capable of preserving noncovalent interactions, it is possible to observe host-guest complexes containing both weak binding guests as well as sterically demanding guests in the mass spectra. The present data suggest that electrospray mass spectrometry is a powerful tool for characterization of supramolecular host-guest complexes.
    MeSH term(s) Crystallization/methods ; Gallium/analysis ; Gallium/chemistry ; Macromolecular Substances/analysis ; Macromolecular Substances/chemistry ; Molecular Conformation ; Naphthalenes/analysis ; Naphthalenes/chemistry ; Spectrometry, Mass, Electrospray Ionization/methods
    Chemical Substances Macromolecular Substances ; Naphthalenes ; naphthalene (2166IN72UN) ; Gallium (CH46OC8YV4)
    Language English
    Publishing date 2006-03
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 1073671-2
    ISSN 1044-0305
    ISSN 1044-0305
    DOI 10.1016/j.jasms.2005.10.011
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Combinatorial Libraries of Metal-Ligand Assemblies with an Encapsulated Guest Molecule Coordination Number Incommensurate Cluster Formation, Part 17. Financial support of this work was provided by NSF CHE-9709621 and a NATO-NSF exchange grant SRG 951516. We thank the Miller Foundation for a fellowship to M.Z. Part 16: R. M. Yeh, M. Ziegler, D. W. Johnson, A. J. Terpin, K. N. Raymond, Inorg. Chem. 2001, in press.

    Ziegler, Marco / Miranda, J. J. / Andersen, Ulla N. / Johnson, Darren W. / Leary, Julie A. / Raymond, Kenneth N.

    Angewandte Chemie (International ed. in English)

    2001  Volume 40, Issue 4, Page(s) 733–736

    Language English
    Publishing date 2001-02-16
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 2011836-3
    ISSN 1521-3773 ; 1433-7851
    ISSN (online) 1521-3773
    ISSN 1433-7851
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article: Bacillus cereus iron uptake protein fishes out an unstable ferric citrate trimer

    Fukushima, Tatsuya / Sia, Allyson K. / Allred, Benjamin E. / Nichiporuk, Rita / Zhou, Zhongrui / Andersen, Ulla N. / Raymond, Kenneth N.

    Proceedings of the National Academy of Sciences of the United States of America

    Volume v. 109,, Issue no. 4

    Abstract: Citrate is a common biomolecule that chelates Fe(III). Many bacteria and plants use ferric citrate to fulfill their nutritional requirement for iron. Only the Escherichia coli ferric citrate outer-membrane transport protein FecA has been characterized; ... ...

    Abstract Citrate is a common biomolecule that chelates Fe(III). Many bacteria and plants use ferric citrate to fulfill their nutritional requirement for iron. Only the Escherichia coli ferric citrate outer-membrane transport protein FecA has been characterized; little is known about other ferric citrate-binding proteins. Here we report a unique siderophore-binding protein from the Gram-positive pathogenic bacterium Bacillus cereus that binds multinuclear ferric citrate complexes. We have demonstrated that B. cereus ATCC 14579 takes up ⁵⁵Fe radiolabeled ferric citrate and that a protein, BC_3466 [renamed FctC (ferric citrate-binding protein C)], binds ferric citrate. The dissociation constant (K d) of FctC at pH 7.4 with ferric citrate (molar ratio 1:50) is 2.6 nM. This is the tightest binding observed of any B. cereus siderophore-binding protein. Nano electrospray ionization–mass spectrometry (nano ESI-MS) analysis of FctC and ferric citrate complexes or citrate alone show that FctC binds diferric di-citrate, and triferric tricitrate, but does not bind ferric di-citrate, ferric monocitrate, or citrate alone. Significantly, the protein selectively binds triferric tricitrate even though this species is naturally present at very low equilibrium concentrations.
    Keywords dissociation ; chelates ; fish ; citrates ; bacteria ; Escherichia coli ; Bacillus cereus ; electrospray ionization mass spectrometry ; radiolabeling ; pH ; iron ; transport proteins
    Language English
    Document type Article
    ISSN 0027-8424
    Database AGRIS - International Information System for the Agricultural Sciences and Technology

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