1
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Sabag-Daigle A, Boulanger EF, Thirugnanasambantham P, Law JD, Bogard AJ, Behrman EJ, Gopalan V, Ahmer BMM. Identification of Small-Molecule Inhibitors of the Salmonella FraB Deglycase Using a Live-Cell Assay. Microbiol Spectr 2023; 11:e0460622. [PMID: 36809033 PMCID: PMC10100877 DOI: 10.1128/spectrum.04606-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 01/18/2023] [Indexed: 02/23/2023] Open
Abstract
Nontyphoidal salmonellosis is one of the most significant foodborne diseases in the United States and globally. There are no vaccines available for human use to prevent this disease, and only broad-spectrum antibiotics are available to treat complicated cases of the disease. However, antibiotic resistance is on the rise and new therapeutics are needed. We previously identified the Salmonella fraB gene, that mutation of causes attenuation of fitness in the murine gastrointestinal tract. The FraB gene product is encoded in an operon responsible for the uptake and utilization of fructose-asparagine (F-Asn), an Amadori product found in several human foods. Mutations in fraB cause an accumulation of the FraB substrate, 6-phosphofructose-aspartate (6-P-F-Asp), which is toxic to Salmonella. The F-Asn catabolic pathway is found only in the nontyphoidal Salmonella serovars, a few Citrobacter and Klebsiella isolates, and a few species of Clostridium; it is not found in humans. Thus, targeting FraB with novel antimicrobials is expected to be Salmonella specific, leaving the normal microbiota largely intact and having no effect on the host. We performed high-throughput screening (HTS) to identify small-molecule inhibitors of FraB using growth-based assays comparing a wild-type Salmonella and a Δfra island mutant control. We screened 224,009 compounds in duplicate. After hit triage and validation, we found three compounds that inhibit Salmonella in an fra-dependent manner, with 50% inhibitory concentration (IC50) values ranging from 89 to 150 μM. Testing these compounds with recombinant FraB and synthetic 6-P-F-Asp confirmed that they are uncompetitive inhibitors of FraB with Ki' (inhibitor constant) values ranging from 26 to 116 μM. IMPORTANCE Nontyphoidal salmonellosis is a serious threat in the United States and globally. We have recently identified an enzyme, FraB, that when mutated renders Salmonella growth defective in vitro and unfit in mouse models of gastroenteritis. FraB is quite rare in bacteria and is not found in humans or other animals. Here, we have identified small-molecule inhibitors of FraB that inhibit the growth of Salmonella. These could provide the foundation for a therapeutic to reduce the duration and severity of Salmonella infections.
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Affiliation(s)
- Anice Sabag-Daigle
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio, USA
| | - Erin F. Boulanger
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio, USA
| | | | - Jamison D. Law
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, USA
| | - Alex J. Bogard
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, USA
| | - Edward J. Behrman
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, USA
| | - Venkat Gopalan
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, USA
| | - Brian M. M. Ahmer
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio, USA
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2
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Thirugnanasambantham P, Kovvali S, Cool A, Gao Y, Sabag-Daigle A, Boulanger EF, Mitton-Fry M, Capua AD, Behrman EJ, Wysocki VH, Lindert S, Ahmer BMM, Gopalan V. Serendipitous Discovery of a Competitive Inhibitor of FraB, a Salmonella Deglycase and Drug Target. Pathogens 2022; 11:1102. [PMID: 36297159 PMCID: PMC9609667 DOI: 10.3390/pathogens11101102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 09/18/2022] [Accepted: 09/20/2022] [Indexed: 11/01/2023] Open
Abstract
Although salmonellosis, an infectious disease, is a significant global healthcare burden, there are no Salmonella-specific vaccines or therapeutics for humans. Motivated by our finding that FraB, a Salmonella deglycase responsible for fructose-asparagine catabolism, is a viable drug target, we initiated experimental and computational efforts to identify inhibitors of FraB. To this end, our recent high-throughput screening initiative yielded almost exclusively uncompetitive inhibitors of FraB. In parallel with this advance, we report here how a separate structural and computational biology investigation of FrlB, a FraB paralog, led to the serendipitous discovery that 2-deoxy-6-phosphogluconate is a competitive inhibitor of FraB (KI ~ 3 μM). However, this compound was ineffective in inhibiting the growth of Salmonella in a liquid culture. In addition to poor uptake, cellular metabolic transformations by a Salmonella dehydrogenase and different phosphatases likely undermined the efficacy of 2-deoxy-6-phosphogluconate in live-cell assays. These insights inform our ongoing efforts to synthesize non-hydrolyzable/-metabolizable analogs of 2-deoxy-6-phosphogluconate. We showcase our findings largely to (re)emphasize the role of serendipity and the importance of multi-pronged approaches in drug discovery.
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Affiliation(s)
| | - Sravya Kovvali
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA
| | - Austin Cool
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Yuan Gao
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
- Resource for Native Mass Spectrometry-Guided Structural Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Anice Sabag-Daigle
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH 43210, USA
| | - Erin F. Boulanger
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH 43210, USA
| | - Mark Mitton-Fry
- Department of Medicinal Chemistry and Pharmacognosy, The Ohio State University, Columbus, OH 43210, USA
| | - Angela Di Capua
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
- Resource for Native Mass Spectrometry-Guided Structural Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Edward J. Behrman
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Vicki H. Wysocki
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
- Resource for Native Mass Spectrometry-Guided Structural Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Steffen Lindert
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Brian M. M. Ahmer
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH 43210, USA
| | - Venkat Gopalan
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA
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Behrman EJ. The Elbs & Boyland-Sims Oxidations: Reactions of Peroxydisulfate-An Updated Literature Survey. MINI-REV ORG CHEM 2021. [DOI: 10.2174/1570193x17999200813153655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Karl Elbs published his discovery of the reaction between phenols and peroxydisulfate in
1893. It was not until fifty years later that Boyland extended the reaction to aromatic amines. There
have been more than 300 citations of these reactions which, although usually giving only modest
yields, are nevertheless useful for their simplicity.
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Affiliation(s)
- Edward J. Behrman
- Ohio State University, Chemistry & Biochemistry, 484 W. 12th Avenue, Columbus, OH 43210, United States
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4
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Behrman EJ, Parkin S. Synthesis and crystal structures of 3,6-di-hydroxy-picolinic acid and its labile inter-mediate dipotassium 3-hy-droxy-6-(sulfonato-oxy)pyridine-2-carboxyl-ate monohydrate. Acta Crystallogr E Crystallogr Commun 2021; 77:623-628. [PMID: 34164140 PMCID: PMC8183438 DOI: 10.1107/s2056989021004904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 05/10/2021] [Indexed: 11/29/2022]
Abstract
A simplified two-step synthesis of 3,6-di-hydroxy-picolinic acid (3-hy-droxy-6-oxo-1,6-di-hydro-pyridine-2-carb-oxy-lic acid), C6H5NO4 (II), an inter-mediate in the metabolism of picolinic acid, is described. The crystal structure of II, along with that of a labile inter-mediate, dipotassium 3-hy-droxy-6-(sulfonato-oxy)pyridine-2-carboxyl-ate monohydrate, 2K+·C6H3NO7S2-·H2O (I), is also described. Compound I comprises a pyridine ring with carboxyl-ate, hydroxyl (connected by an intra-molecular O-H⋯O hydrogen bond), and sulfate groups at the 2-, 3-, and 6-positions, respectively, along with two potassium cations for charge balance and one water mol-ecule of crystallization. These components are connected into a three-dimensional network by O-H⋯O hydrogen bonds arising from the water mol-ecule, C-H⋯O inter-actions and π-π stacking of pyridine rings. In II, the ring nitro-gen atom is protonated, with charge balance provided by the carboxyl-ate group (i.e., a zwitterion). The intra-molecular O-H⋯O hydrogen bond observed in I is preserved in II. Crystals of II have unusual space-group symmetry of type Abm2 in which extended planar networks of O-H⋯O and N-H⋯O hydrogen-bonded mol-ecules form sheets lying parallel to the ac plane, constrained to b = 0.25 (and 0.75). The structure was refined as a 50:50 inversion twin. A minor disorder component was modeled by reflection of the major component across a mirror plane perpendicular to c.
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Affiliation(s)
- Edward J. Behrman
- Department of Chemistry & Biochemistry, The Ohio State University, 484 W. 12th Avenue, Columbus, Ohio, 43210, USA
| | - Sean Parkin
- Department of Chemistry, University of Kentucky, 505 Rose Street, Lexington, Kentucky, 40506, USA
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Behrman EJ, Hansen AL, Yuan C, Parkin S. 4,15-Dimethyl-7,12-diazo-niatri-cyclo-[10.4.0.0 2,7]hexa-deca-1(12),2,4,6,13,15-hexa-ene dibromide monohydrate. Acta Crystallogr E Crystallogr Commun 2020; 76:1467-1471. [PMID: 32939301 PMCID: PMC7472763 DOI: 10.1107/s2056989020011147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 08/13/2020] [Indexed: 11/28/2022]
Abstract
The crystal structure of the viologen 4,4′-dimethyl-2,2′-dipyridyl-N,N′-tetramethylene dibromide monohydrate is presented, along with details of an improved synthesis and NMR spectroscopic analysis. The title compound, C16H20N22+·2Br−·H2O (1) is a member of the class of compounds called viologens. Viologens are quaternary salts of dipyridyls and are especially useful as redox indicators as a result of their large negative one-electron reduction potentials. Compound 1 consists of a dication composed of a pair of 4-methylpyridine rings mutually joined at the 2-position, with a dihedral angle between the pyridine rings of 62.35 (4)°. In addition, the rings are tethered via the pyridine nitrogen atoms by a tetramethylene bridge. Charge balance is provided by a pair of bromide anions, which are hydrogen bonded to a single water molecule [DO⋯Br = 3.3670 (15) and 3.3856 (15) Å]. The crystal structure of 1, details of an improved synthesis, and a full analysis of its NMR spectra are presented.
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Affiliation(s)
- Edward J Behrman
- Department of Chemistry & Biochemistry, The Ohio State University, 484 W. 12th Avenue, Columbus, Ohio, 43210, USA
| | - Alexandar L Hansen
- Campus Chemical Instrument Center, The Ohio State University, 496 W. 12th Avenue, Columbus, Ohio, 43210, USA
| | - Chunhua Yuan
- Campus Chemical Instrument Center, The Ohio State University, 496 W. 12th Avenue, Columbus, Ohio, 43210, USA
| | - Sean Parkin
- Department of Chemistry, University of Kentucky, 505 Rose Street, Lexington, Kentucky, 40506, USA
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6
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Kountz DJ, Behrman EJ, Zhang L, Krzycki JA. MtcB, a member of the MttB superfamily from the human gut acetogen Eubacterium limosum, is a cobalamin-dependent carnitine demethylase. J Biol Chem 2020; 295:11971-11981. [PMID: 32571881 PMCID: PMC7443480 DOI: 10.1074/jbc.ra120.012934] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 06/18/2020] [Indexed: 12/22/2022] Open
Abstract
The trimethylamine methyltransferase MttB is the first described member of a superfamily comprising thousands of microbial proteins. Most members of the MttB superfamily are encoded by genes that lack the codon for pyrrolysine characteristic of trimethylamine methyltransferases, raising questions about the activities of these proteins. The superfamily member MtcB is found in the human intestinal isolate Eubacterium limosum ATCC 8486, an acetogen that can grow by demethylation of l-carnitine. Here, we demonstrate that MtcB catalyzes l-carnitine demethylation. When growing on l-carnitine, E. limosum excreted the unusual biological product norcarnitine as well as acetate, butyrate, and caproate. Cellular extracts of E. limosum grown on l-carnitine, but not lactate, methylated cob-(I)alamin or tetrahydrofolate using l-carnitine as methyl donor. MtcB, along with the corrinoid protein MtqC and the methylcorrinoid:tetrahydrofolate methyltransferase MtqA, were much more abundant in E. limosum cells grown on l-carnitine than on lactate. Recombinant MtcB methylates either cob(I)alamin or Co(I)-MtqC in the presence of l-carnitine and, to a much lesser extent, γ-butyrobetaine. Other quaternary amines were not substrates. Recombinant MtcB, MtqC, and MtqA methylated tetrahydrofolate via l-carnitine, forming a key intermediate in the acetogenic Wood-Ljungdahl pathway. To our knowledge, MtcB methylation of cobalamin or Co(I)-MtqC represents the first described mechanism of biological l-carnitine demethylation. The conversion of l-carnitine and its derivative γ-butyrobetaine to trimethylamine by the gut microbiome has been linked to cardiovascular disease. The activities of MtcB and related proteins in E. limosum might demethylate proatherogenic quaternary amines and contribute to the perceived health benefits of this human gut symbiont.
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Affiliation(s)
- Duncan J Kountz
- Department of Microbiology, Ohio State University, Columbus, Ohio, USA
| | - Edward J Behrman
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, Ohio, USA
| | - Liwen Zhang
- Campus Chemical Instrument Center Mass Spectrometry and Proteomics Facility, Ohio State University, Columbus, Ohio, USA
| | - Joseph A Krzycki
- Department of Microbiology, Ohio State University, Columbus, Ohio, USA; Ohio State Biochemistry Program, Ohio State University, Columbus, Ohio, USA.
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7
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Picking JW, Behrman EJ, Zhang L, Krzycki JA. MtpB, a member of the MttB superfamily from the human intestinal acetogen Eubacterium limosum, catalyzes proline betaine demethylation. J Biol Chem 2019; 294:13697-13707. [PMID: 31341018 DOI: 10.1074/jbc.ra119.009886] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 07/22/2019] [Indexed: 12/11/2022] Open
Abstract
The trimethylamine methyltransferase MttB is the founding member of a widely distributed superfamily of microbial proteins. Genes encoding most members of the MttB superfamily lack the codon for pyrrolysine that distinguishes previously characterized trimethylamine methyltransferases, leaving the function(s) of most of the enzymes in this superfamily unknown. Here, investigating the MttB family member MtpB from the human intestinal isolate Eubacterium limosum ATCC 8486, an acetogen that excretes N-methyl proline during growth on proline betaine, we demonstrate that MtpB catalyzes anoxic demethylation of proline betaine. MtpB along with MtqC (a corrinoid protein) and MtqA (a methylcorrinoid:tetrahydrofolate methyltransferase) was much more abundant in E. limosum cells grown on proline betaine than on lactate. We observed that recombinant MtpB methylates Co(I)-MtqC in the presence of proline betaine and that other quaternary amines are much less preferred substrates. MtpB, MtqC, and MtqA catalyze tetrahydrofolate methylation with proline betaine, thereby forming a key intermediate in the Wood-Ljungdahl acetogenesis pathway. To our knowledge, MtpB methylation of Co(I)-MtqC for the subsequent methylation of tetrahydrofolate represents the first described anoxic mechanism of proline betaine demethylation. The activities of MtpB and associated proteins in acetogens or other anaerobes provide a possible mechanism for the production of N-methyl proline by the gut microbiome. MtpB's activity characterized here strengthens the hypothesis that much of the MttB superfamily comprises quaternary amine-dependent methyltransferases.
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Affiliation(s)
- Jonathan W Picking
- Ohio State Biochemistry Program, Ohio State University, Columbus, Ohio 43210
| | - Edward J Behrman
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, Ohio 43210
| | - Liwen Zhang
- Campus Chemical Instrument Center Mass Spectrometry and Proteomics Facility, Ohio State University, Columbus, Ohio 43210
| | - Joseph A Krzycki
- Ohio State Biochemistry Program, Ohio State University, Columbus, Ohio 43210 .,Department of Microbiology, Ohio State University, Columbus, Ohio 43210
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8
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Behrman EJ. Comment on Jiang Y, Zhang J, Xi B, et al. [Degradation of toluene-2,4-diamine by persulphate. Environ Tech. 2015;36:1441-1447]. Environ Technol 2019; 40:1769. [PMID: 30468631 DOI: 10.1080/09593330.2018.1552726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 11/21/2018] [Indexed: 06/09/2023]
Affiliation(s)
- E J Behrman
- a Department of Chemistry & Biochemistry , Ohio State University , Columbus , OH , USA
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9
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Behrman EJ. Peroxydisulfate chemistry in the environmental literature: A brief critique. J Hazard Mater 2019; 365:971. [PMID: 30454857 DOI: 10.1016/j.jhazmat.2018.11.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 11/05/2018] [Indexed: 06/09/2023]
Affiliation(s)
- E J Behrman
- Department of Chemistry & Biochemistry, Ohio State University, United States.
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10
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Behrman EJ. Comment on Lominchar et al. [1]. Environ Technol 2019; 40:132. [PMID: 29558841 DOI: 10.1080/09593330.2018.1451615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Affiliation(s)
- Edward J Behrman
- a Chemistry & Biochemistry , Ohio State University , Columbus , OH , USA
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11
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Affiliation(s)
- Suresh Pal
- Department of Chemistry & Biochemistry, The Ohio State University, 484 W. 12th Avenue, Columbus, OH, USA
| | - Jikang Wu
- Department of Chemistry & Biochemistry, The Ohio State University, 484 W. 12th Avenue, Columbus, OH, USA
| | - Edward J Behrman
- Department of Chemistry & Biochemistry, The Ohio State University, 484 W. 12th Avenue, Columbus, OH, USA.
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12
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Behrman EJ. Of: C. Liang & J.-H. Lei, Water Environ. Res., 87, 656-659 (2015). Water Environ Res 2018; 90:479. [PMID: 29678217 DOI: 10.2175/106143017x15131012153013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
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13
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Behrman EJ. Comment on "Changes in activation energy and kinetics of heat-activated persulfate oxidation of phenol in response to changes in pH and temperature". Chemosphere 2018; 194:42. [PMID: 29197247 DOI: 10.1016/j.chemosphere.2017.11.152] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 11/25/2017] [Indexed: 06/07/2023]
Affiliation(s)
- E J Behrman
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA.
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14
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Affiliation(s)
- E J Behrman
- Department of Chemistry & Biochemistry, The Ohio State University, Columbus, OH 43210.
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15
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Wu J, Sabag-Daigle A, Metz TO, Deatherage Kaiser BL, Gopalan V, Behrman EJ, Wysocki VH, Ahmer BMM. Measurement of Fructose-Asparagine Concentrations in Human and Animal Foods. J Agric Food Chem 2018; 66:212-217. [PMID: 29232127 PMCID: PMC6191295 DOI: 10.1021/acs.jafc.7b04237] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The food-borne bacterial pathogen, Salmonella enterica, can utilize fructose-asparagine (F-Asn) as its sole carbon and nitrogen source. F-Asn is the product of an Amadori rearrangement following the nonenzymatic condensation of glucose and asparagine. Heating converts F-Asn via complex Maillard reactions to a variety of molecules that contribute to the color, taste, and aroma of heated foods. Among these end derivatives is acrylamide, which is present in some foods, especially in fried potatoes. The F-Asn utilization pathway in Salmonella, specifically FraB, is a potential drug target because inhibition of this enzyme would lead to intoxication of Salmonella in the presence of F-Asn. However, F-Asn would need to be packaged with the FraB inhibitor or available in human foods. To determine if there are foods that have sufficient F-Asn, we measured F-Asn concentrations in a variety of human and animal foods. The 400 pmol/mg F-Asn found in mouse chow is sufficient to intoxicate a Salmonella fraB mutant in mouse models of salmonellosis, and several human foods were found to have F-Asn at this level or higher (fresh apricots, lettuce, asparagus, and canned peaches). Much higher concentrations (11 000-35 000 pmol/mg dry weight) were found in heat-dried apricots, apples, and asparagus. This report reveals possible origins of F-Asn as a nutrient source for Salmonella and identifies foods that could be used together with a FraB inhibitor as a therapeutic agent for Salmonella.
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Affiliation(s)
- Jikang Wu
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Anice Sabag-Daigle
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio 43210, United States
| | - Thomas O. Metz
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland 99352, Washington, United States
| | - Brooke L. Deatherage Kaiser
- Signature Sciences and Technology Division, Pacific Northwest National Laboratory, Richland 99352, Washington, United States
| | - Venkat Gopalan
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Edward J. Behrman
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Vicki H. Wysocki
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
- Corresponding Authors:; Phone: 614-292-8687. ; Phone: 614-292-1919
| | - Brian M. M. Ahmer
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio 43210, United States
- Corresponding Authors:; Phone: 614-292-8687. ; Phone: 614-292-1919
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16
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Biswas PK, Behrman EJ, Gopalan V. Characterization of a Salmonella sugar kinase essential for the utilization of fructose-asparagine. Biochem Cell Biol 2016; 95:304-309. [PMID: 28177776 DOI: 10.1139/bcb-2016-0138] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Salmonella can utilize fructose-asparagine (F-Asn), a naturally occurring Amadori product, as its sole carbon and nitrogen source. Conversion of F-Asn to the common intermediates glucose-6-phosphate, aspartate, and ammonia was predicted to involve the sequential action of an asparaginase, a kinase, and a deglycase. Mutants lacking the deglycase are highly attenuated in mouse models of intestinal inflammation owing to the toxic build-up of the deglycase substrate. The limited distribution of this metabolic pathway in the animal gut microbiome raises the prospects for antibacterial discovery. We report the biochemical characterization of the kinase that was expected to transform fructose-aspartate to 6-phosphofructose-aspartate during F-Asn utilization. In addition to confirming its anticipated function, we determined through studies of fructose-aspartate analogues that this kinase exhibits a substrate-specificity with greater tolerance to changes to the amino acid (including the d-isomer of aspartate) than to the sugar.
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Affiliation(s)
- Pradip K Biswas
- Department of Chemistry & Biochemistry, The Ohio State University, Columbus, OH 43210, USA.,Department of Chemistry & Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Edward J Behrman
- Department of Chemistry & Biochemistry, The Ohio State University, Columbus, OH 43210, USA.,Department of Chemistry & Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Venkat Gopalan
- Department of Chemistry & Biochemistry, The Ohio State University, Columbus, OH 43210, USA.,Department of Chemistry & Biochemistry, The Ohio State University, Columbus, OH 43210, USA
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Hansen AL, Behrman EJ. Synthesis of 6-phosphofructose aspartic acid and some related Amadori compounds. Carbohydr Res 2016; 431:1-5. [PMID: 27258673 PMCID: PMC4945423 DOI: 10.1016/j.carres.2016.05.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 05/05/2016] [Accepted: 05/07/2016] [Indexed: 12/17/2022]
Abstract
We describe the synthesis and characterization of 6-phosphofructose-aspartic acid, an intermediate in the metabolism of fructose-asparagine by Salmonella. We also report improved syntheses of fructose-asparagine itself and of fructose-aspartic acid.
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Affiliation(s)
- Alexandar L Hansen
- Campus Chemical Instrument Center, The Ohio State University, 496 W. 12th Avenue, Columbus, OH 43210, USA.
| | - Edward J Behrman
- Department of Chemistry & Biochemistry, The Ohio State University, 484 W. 12th Avenue, Columbus, OH 43210, USA.
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Sabag-Daigle A, Blunk HM, Sengupta A, Wu J, Bogard AJ, Ali MM, Stahl C, Wysocki VH, Gopalan V, Behrman EJ, Ahmer BMM. A metabolic intermediate of the fructose-asparagine utilization pathway inhibits growth of a Salmonella fraB mutant. Sci Rep 2016; 6:28117. [PMID: 27403719 PMCID: PMC4941530 DOI: 10.1038/srep28117] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 05/27/2016] [Indexed: 11/09/2022] Open
Abstract
Insertions in the Salmonella enterica fra locus, which encodes the fructose-asparagine (F-Asn) utilization pathway, are highly attenuated in mouse models of inflammation (>1000-fold competitive index). Here, we report that F-Asn is bacteriostatic to a fraB mutant (IC50 19 μM), but not to the wild-type or a fra island deletion mutant. We hypothesized that the presence of FraD kinase and absence of FraB deglycase causes build-up of a toxic metabolite: 6-phosphofructose-aspartate (6-P-F-Asp). We used biochemical assays to assess FraB and FraD activities, and mass spectrometry to confirm that the fraB mutant accumulates 6-P-F-Asp. These results, together with our finding that mutants lacking fraD or the fra island are not attenuated in mice, suggest that the extreme attenuation of a fraB mutant stems from 6-P-F-Asp toxicity. Salmonella FraB is therefore an excellent drug target, a prospect strengthened by the absence of the fra locus in most of the gut microbiota.
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Affiliation(s)
- Anice Sabag-Daigle
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH 43210, USA.,Center for Microbial Interface Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Henry M Blunk
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA
| | - Anindita Sengupta
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Jikang Wu
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Alexander J Bogard
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Mohamed M Ali
- Center for Microbial Interface Biology, The Ohio State University, Columbus, OH 43210, USA.,Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA.,Department of Medical Microbiology and Immunology, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Christopher Stahl
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA
| | - Vicki H Wysocki
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Venkat Gopalan
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Edward J Behrman
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Brian M M Ahmer
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH 43210, USA.,Center for Microbial Interface Biology, The Ohio State University, Columbus, OH 43210, USA.,Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA
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Abstract
Deuterium kinetic isotope effects support a mechanism for the Boyland–Sims oxidation involving a nucleophilic displacement by the amine on the peroxide oxygen.
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Affiliation(s)
- Edward J. Behrman
- Department of Chemistry and Biochemistry, The Ohio State University, 484 W. 12th Avenue, Columbus, Ohio, USA
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Lee MM, Fekner T, Lu J, Heater BS, Behrman EJ, Zhang L, Hsu PH, Chan MK. Pyrrolysine-Inspired Protein Cyclization. Chembiochem 2014; 15:1769-72. [DOI: 10.1002/cbic.201402129] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Indexed: 11/05/2022]
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Ali MM, Newsom DL, González JF, Sabag-Daigle A, Stahl C, Steidley B, Dubena J, Dyszel JL, Smith JN, Dieye Y, Arsenescu R, Boyaka PN, Krakowka S, Romeo T, Behrman EJ, White P, Ahmer BMM. Fructose-asparagine is a primary nutrient during growth of Salmonella in the inflamed intestine. PLoS Pathog 2014; 10:e1004209. [PMID: 24967579 PMCID: PMC4072780 DOI: 10.1371/journal.ppat.1004209] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 05/09/2014] [Indexed: 12/21/2022] Open
Abstract
Salmonella enterica serovar Typhimurium (Salmonella) is one of the most significant food-borne pathogens affecting both humans and agriculture. We have determined that Salmonella encodes an uptake and utilization pathway specific for a novel nutrient, fructose-asparagine (F-Asn), which is essential for Salmonella fitness in the inflamed intestine (modeled using germ-free, streptomycin-treated, ex-germ-free with human microbiota, and IL10-/- mice). The locus encoding F-Asn utilization, fra, provides an advantage only if Salmonella can initiate inflammation and use tetrathionate as a terminal electron acceptor for anaerobic respiration (the fra phenotype is lost in Salmonella SPI1- SPI2- or ttrA mutants, respectively). The severe fitness defect of a Salmonella fra mutant suggests that F-Asn is the primary nutrient utilized by Salmonella in the inflamed intestine and that this system provides a valuable target for novel therapies.
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Affiliation(s)
- Mohamed M. Ali
- Department of Microbiology, The Ohio State University, Columbus, Ohio, United States of America
- Department of Medical Microbiology and Immunology, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - David L. Newsom
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
| | - Juan F. González
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio, United States of America
| | - Anice Sabag-Daigle
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio, United States of America
| | - Christopher Stahl
- Department of Microbiology, The Ohio State University, Columbus, Ohio, United States of America
| | - Brandi Steidley
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio, United States of America
| | - Judith Dubena
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, United States of America
| | - Jessica L. Dyszel
- Department of Microbiology, The Ohio State University, Columbus, Ohio, United States of America
| | - Jenee N. Smith
- Department of Microbiology, The Ohio State University, Columbus, Ohio, United States of America
| | - Yakhya Dieye
- Department of Microbiology, The Ohio State University, Columbus, Ohio, United States of America
| | - Razvan Arsenescu
- Department of Internal Medicine, The Ohio State University, Columbus, Ohio, United States of America
| | - Prosper N. Boyaka
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, United States of America
| | - Steven Krakowka
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio, United States of America
| | - Tony Romeo
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, United States of America
| | - Edward J. Behrman
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, United States of America
| | - Peter White
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
| | - Brian M. M. Ahmer
- Department of Microbiology, The Ohio State University, Columbus, Ohio, United States of America
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio, United States of America
- * E-mail:
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Abstract
The syntheses of 5-hydroxy-6-bromo-2-pyridone, 5-hydroxy-6-nitroso-2-pyridone, 3-bromo-5-acetoxy-2-pyridone, and 3-nitro-5-acetoxy-2-pyridone are described.
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Affiliation(s)
- Edward J. Behrman
- Department of Chemistry and Biochemistry, The Ohio State University 484 W. 12th Avenue, Columbus, Ohio 43210, USA
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Yao Y, Tang H, Ren H, Yu H, Wang L, Zhang W, Behrman EJ, Xu P. Iron(II)-dependent dioxygenase and N-formylamide deformylase catalyze the reactions from 5-hydroxy-2-pyridone to maleamate. Sci Rep 2013; 3:3235. [PMID: 24241081 PMCID: PMC3831237 DOI: 10.1038/srep03235] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 10/31/2013] [Indexed: 11/24/2022] Open
Abstract
5-Hydroxy-2-pyridone (2,5-DHP) is a central metabolic intermediate in catabolism of many pyridine derivatives, and has been suggested as a potential carcinogen. 2,5-DHP is frequently transformed to N-formylmaleamic acid (NFM) by a 2,5-DHP dioxygenase. Three hypotheses were formerly discussed for conversion of 2,5-DHP to maleamate. Based on enzymatic reactions of dioxygenase (Hpo) and N-formylamide deformylase (Nfo), we demonstrated that the dioxygenase does not catalyze the hydrolysis of NFM but rather that this activity is brought about by a separate deformylase. We report that the deformylase acts both on NFM and its trans-isomer, N-formylfumaramic acid (NFF), but the catalytic efficiency of Nfo for NFM is about 1,400 times greater than that for NFF. In addition, we uncover catalytic and structural characteristics of the new family that the Hpo belongs to, and support a potential 2-His-1-carboxylate motif (HX52HXD) by three-dimensional modeling and site-directed mutagenesis. This study provides a better understanding of 2,5-DHP catabolism.
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Affiliation(s)
- Yuxiang Yao
- State Key Laboratory of Microbial Metabolism, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, PR China
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Parkin SR, Behrman EJ. Channel-forming solvate crystals and isostructural solvent-free powder of 5-hydroxy-6-methyl-2-pyridone. Acta Crystallogr C 2011; 67:o324-8. [DOI: 10.1107/s0108270111026254] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Accepted: 07/01/2011] [Indexed: 11/10/2022] Open
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Parkin SR, Behrman EJ. Channel-forming solvates of 6-chloro-2,5-dihydroxypyridine and its solvent-free tautomer 6-chloro-5-hydroxy-2-pyridone. Acta Crystallogr C 2009; 65:o529-33. [PMID: 19805888 DOI: 10.1107/s0108270109036476] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Accepted: 09/09/2009] [Indexed: 11/11/2022] Open
Abstract
On crystallization from CHCl3, CCl4, CH2ClCH2Cl and CHCl2CHCl2, 6-chloro-5-hydroxy-2-pyridone, C5H4ClNO2, (I), undergoes a tautomeric rearrangement to 6-chloro-2,5-dihydroxypyridine, (II). The resulting crystals, viz. 6-chloro-2,5-dihydroxypyridine chloroform 0.125-solvate, C5H4ClNO(2).0.125CHCl3, (IIa), 6-chloro-2,5-dihydroxypyridine carbon tetrachloride 0.125-solvate, C5H4ClNO(2)..0.125CCl4, (IIb), 6-chloro-2,5-dihydroxypyridine 1,2-dichloroethane solvate, C5H4ClNO2.C2H4Cl2, (IIc), and 6-chloro-2,5-dihydroxypyridine 1,1,2,2-tetrachloroethane solvate, C5H4ClNO2.C2H2Cl4, (IId), have I4(1)/a symmetry, and incorporate extensively disordered solvent in channels that run the length of the c axis. Upon gentle heating to 378 K in vacuo, these crystals sublime to form solvent-free crystals with P2(1)/n symmetry that are exclusively the pyridone tautomer, (I). In these sublimed pyridone crystals, inversion-related molecules form R(2)(2)(8) dimers via pairs of N-H...O hydrogen bonds. The dimers are linked by O-H...O hydrogen bonds into R(4)(6)(28) motifs, which join to form pleated sheets that stack along the a axis. In the channel-containing pyridine solvate crystals, viz. (IIa)-(IId), two independent host molecules form an R(2)(2)(8) dimer via a pair of O-H...N hydrogen bonds. One molecule is further linked by O-H...O hydrogen bonds to two 4(1) screw-related equivalents to form a helical motif parallel to the c axis. The other independent molecule is O-H...O hydrogen bonded to two 4 related equivalents to form tetrameric R(4)(4)(28) rings. The dimers are pi-pi stacked with inversion-related dimers, which in turn stack the R(4)(4)(28) rings along c to form continuous solvent-accessible channels. CHCl3, CCl4, CH2ClCH2Cl and CHCl2CHCl2 solvent molecules are able to occupy these channels but are disordered by virtue of the 4 site symmetry within the channels.
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Affiliation(s)
- Sean R Parkin
- Department of Chemistry, University of Kentucky, Lexington, KY 40506-0055, USA.
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27
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Abstract
The conversion of phosphoenolpyruvate (PEP) in glycolysis is coupled with the formation of ATP. This note discusses the origin of the energy required for ATP formation as arising from redistribution of energy in PEP when compared with its precursor, 2-phosphoglycerate.
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Affiliation(s)
- E J Behrman
- Department of Biochemistry, The Ohio State University, Columbus, Ohio 43210.
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28
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Abstract
Two syntheses of N-formylmaleamic acid and some related N-formylamides are described which take place under very mild conditions.
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Affiliation(s)
- Edward J. Behrman
- Department of Biochemistry, The Ohio State University, Columbus, OH 43210
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29
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Kawamoto SA, Sudhahar CG, Hatfield CL, Sun J, Behrman EJ, Gopalan V. Studies on the mechanism of inhibition of bacterial ribonuclease P by aminoglycoside derivatives. Nucleic Acids Res 2008; 36:697-704. [PMID: 18084035 PMCID: PMC2241863 DOI: 10.1093/nar/gkm1088] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2007] [Revised: 11/19/2007] [Accepted: 11/20/2007] [Indexed: 11/13/2022] Open
Abstract
Ribonuclease P (RNase P) is a Mg2+-dependent endoribonuclease responsible for the 5'-maturation of transfer RNAs. It is a ribonucleoprotein complex containing an essential RNA and a varying number of protein subunits depending on the source: at least one, four and nine in Bacteria, Archaea and Eukarya, respectively. Since bacterial RNase P is required for viability and differs in structure/subunit composition from its eukaryal counterpart, it is a potential antibacterial target. To elucidate the basis for our previous finding that the hexa-arginine derivative of neomycin B is 500-fold more potent than neomycin B in inhibiting bacterial RNase P, we synthesized hexa-guanidinium and -lysyl conjugates of neomycin B and compared their inhibitory potential. Our studies indicate that side-chain length, flexibility and composition cumulatively account for the inhibitory potency of the aminoglycoside-arginine conjugates (AACs). We also demonstrate that AACs interfere with RNase P function by displacing Mg2+ ions. Moreover, our finding that an AAC can discriminate between a bacterial and archaeal (an experimental surrogate for eukaryal) RNase P holoenzyme lends promise to the design of aminoglycoside conjugates as selective inhibitors of bacterial RNase P, especially once the structural differences in RNase P from the three domains of life have been established.
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Affiliation(s)
| | | | | | | | | | - Venkat Gopalan
- Department of Biochemistry, The Ohio State University, Columbus, OH 43210, USA
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30
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Abstract
This paper reviews the recent literature on the title reactions and updates a 1988 review.
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Affiliation(s)
- E J Behrman
- Department of Biochemistry, The Ohio State University, 484 West 12th Avenue, Columbus, OH 43210, USA.
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Papaefstathiou GS, Manessi S, Raptopoulou CP, Behrman EJ, Zafiropoulos TF. The first metal complex of 5-hydroxyorotic acid: dimethylammonium bis(N,N-dimethylformamide) bis(5-hydroxyorotato(-2))gallate(III). INORG CHEM COMMUN 2004. [DOI: 10.1016/j.inoche.2003.10.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Wu CW, Eder PS, Gopalan V, Behrman EJ. Kinetics of coupling reactions that generate monothiophosphate disulfides: implications for modification of RNAs. Bioconjug Chem 2001; 12:842-4. [PMID: 11716671 DOI: 10.1021/bc0100612] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The inclusion of guanosine-5'-monothiophosphate (GMPS) in an in vitro transcription reaction facilitates enzymatic synthesis of an RNA transcript with a monothiophosphate group at the 5' end. A kinetic study of the modification reactions that generate monothiophosphate disulfide linkages with either 5'-GMPS alone or 5'-GMPS-primed RNA as the substrate revealed that the second-order rate constants increased as the pH was decreased. For example, when the reaction pH was lowered from 8 to 4, the k2 value for the coupling reaction between N-(6-[biotinamido]hexyl)-3'-(2'-pyridyldithio)propionamide (biotin-HPDP) and GMPS increased 67-fold from 1.84 to 123 M(-1) x s(-1). In addition to discussing a possible mechanism for coupling reactions that involve GMPS and disulfides, we also indicate conditions that are likely to be optimal for modification of the nucleophilic sulfur in 5'-GMPS-primed RNAs.
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Affiliation(s)
- C W Wu
- Department of Biochemistry, The Ohio State University, Columbus, Ohio 43210-1292, USA
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Behrman EJ, Dean DH. Sodium peroxydisulfate is a stable and cheap substitute for ammonium peroxydisulfate (persulfate) in polyacrylamide gel electrophoresis. J Chromatogr B Biomed Sci Appl 1999; 723:325-6. [PMID: 10080663 DOI: 10.1016/s0378-4347(98)00525-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Abstract
Sucrose 6'-phosphate (3) is the key intermediate for sucrose (1) synthesis in plants [1]. It has recently become commercially available at ca. $1500/g (Sigma). The only chemical synthesis is that of Buchanan et al. [2]. This six-step procedure, while unambiguous, gives an overall yield of only ca. 6%. We describe here a simplified route (2 steps) with an unoptimized yield of ca. 15%. Our strategy was to use a phosphorylation reagent selective for primary hydroxyl groups and thus to avoid the necessity for blocking all of the secondary ones. Sowa and Ouchi [3] described a suitable system which they used very effectively for the synthesis of 5'-nucleotides from unprotected nucleosides. We applied this reagent to 2,1':4,6-di-O-isopropylidenesucrose (2) [4] in which the only unprotected primary hydroxyl group is that at the 6'-position (Scheme 1). The identity of the product was established by comparison of its rotation with the literature value and by the correspondence of its 1H and 13C NMR spectra with those of an authentic sample synthesized by Buchanan's method (Sigma) 1H assignments were made with the help of the assignments of du Penhoat et al. [5] for sucrose and the results of a one-bond H-C COSY experiment (Fig. 1). The 13C spectrum showed that all of the resonances were shifted downfield by ca. 0.5 ppm as compared with sucrose [6] except for the C-5' doublet which was shifted upfield by 0.5 ppm and the C-6' doublet which was shifted downfield by 2.2 ppm (Table 1).
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Affiliation(s)
- K B Kim
- Department of Biochemistry, Ohio State University, Columbus, 43210, USA
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Barber GA, Behrman EJ. The synthesis and characterization of uridine 5'-(beta-L-rhamnopyranosyl diphosphate) and its role in the enzymic synthesis of rutin. Arch Biochem Biophys 1991; 288:239-42. [PMID: 1898019 DOI: 10.1016/0003-9861(91)90190-t] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Uridine 5'-(beta-L-rhamnopyranosyl diphosphate) was synthesized by the condensation of uridine 5'-diphenylpyrophosphate and beta-L-rhamnopyranosyl phosphate. That sugar 1-phosphate was made via the phosphitylation of the hemiacetal hydroxyl group of 2,3,4-tetra-O-acetyl-beta-L-rhamnopyranose. An enzyme preparation from the primary leaves of mung bean (Phaseolus aureus) was shown to catalyze the transfer of L-rhamnose from UDP-beta-L-rhamnose to the flavonol D-glucoside isoquercitrin to form rutin.
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Affiliation(s)
- G A Barber
- Department of Biochemistry, Ohio State University, Columbus 43210
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Appleton ML, Cottrell CE, Behrman EJ. Chemical transformation of sugar nucleotides: acetylation of uridine 5'-(alpha-D-glucopyranosyl diphosphate). Carbohydr Res 1990; 206:373-7. [PMID: 2073642 DOI: 10.1016/0008-6215(90)80077-g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- M L Appleton
- Department of Biochemistry, Ohio State University, Columbus 43210
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Appleton ML, Cottrell CE, Behrman EJ. N.m.r. assignments of acetyl and trityl groups in derivatized carbohydrates via proton-carbon long-range couplings. Carbohydr Res 1986; 158:227-35. [PMID: 3829039 DOI: 10.1016/0008-6215(86)84020-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Abstract
The specific cleavage of proteins following reaction with osmium tetroxide is slowed down by tertiary amines which are known to be good ligands for osmium. Bidentate ligands are more effective than monodentate ligands. These same ligands also promote an intermolecular cross-linking reaction.
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Deetz JS, Behrman EJ. Reaction of osmium reagents with amino acids and proteins. Reactivity of amino acid residues and peptide bond cleavage. Int J Pept Protein Res 1981; 17:495-500. [PMID: 7309353 DOI: 10.1111/j.1399-3011.1981.tb02019.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
We report a study of the relative reactivity of the common amino acids and of their residues in lysozyme with osmium tetroxide, the osmium tetroxide-pyridine reagent, and with the oxo-osmium(VI)-pyridine reagent. With free amino acids, the osmium(VIII) reagents are most reactive with Met, Cys, His, Thr, Ser, Trp, Lys, and Pro; the osmium(VI) reagent only reacts significantly with His, Met, Cys, Thr, and Ser. In lysozyme, only Cys, Met, and Trp react extensively with the osmium(VIII) reagents; with the osmium(VI) reagent, Cys and Met are most reactive. We also note evidence both for cross-linking of proteins and for peptide bond cleavage, which appears to have considerable specificity for tryptophanyl residues.
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Zablocki W, Behrman EJ, Barber GA. Resolution of D- and L-galactose peracetates as their bis(ethyl L-lactate) acetals by gas-liquid chromatography. J Biochem Biophys Methods 1979; 1:253-6. [PMID: 552389 DOI: 10.1016/0165-022x(79)90011-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Reaction between ethyl L-lactate and each of a pair of sugar enantiomers, the peracetylated D-galactose and L-galactose diethyldithioacetals, produced two acyclic diasterioisomers. They could be separated by conventional gas-liquid chromatography. The corresponding fucose diastereomers were also separated. This process should make it possible to develop a general analytical method by which small amounts of enantiomeric sugars can be identified and their quantities measured.
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