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Leus IV, Weeks JW, Bonifay V, Shen Y, Yang L, Cooper CJ, Nath D, Duerfeldt AS, Smith JC, Parks JM, Rybenkov VV, Zgurskaya HI. Author Correction: Property space mapping of Pseudomonas aeruginosa permeability to small molecules. Sci Rep 2023; 13:8918. [PMID: 37264107 DOI: 10.1038/s41598-023-35960-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023] Open
Affiliation(s)
- Inga V Leus
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK, 73019, USA
| | - Jon W Weeks
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK, 73019, USA
| | - Vincent Bonifay
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK, 73019, USA
| | - Yue Shen
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Liang Yang
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK, 73019, USA
| | - Connor J Cooper
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Dinesh Nath
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK, 73019, USA
| | - Adam S Duerfeldt
- Department of Medicinal Chemistry, University of Minnesota, 717 Delaware St. SE, Minneapolis, MN, 55414, USA
| | - Jeremy C Smith
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN, 37996, USA
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Jerry M Parks
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Valentin V Rybenkov
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK, 73019, USA.
| | - Helen I Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK, 73019, USA.
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Sanders BC, Pokhrel S, Labbe AD, Mathews II, Cooper CJ, Davidson RB, Phillips G, Weiss KL, Zhang Q, O'Neill H, Kaur M, Schmidt JG, Reichard W, Surendranathan S, Parvathareddy J, Phillips L, Rainville C, Sterner DE, Kumaran D, Andi B, Babnigg G, Moriarty NW, Adams PD, Joachimiak A, Hurst BL, Kumar S, Butt TR, Jonsson CB, Ferrins L, Wakatsuki S, Galanie S, Head MS, Parks JM. Potent and selective covalent inhibition of the papain-like protease from SARS-CoV-2. Nat Commun 2023; 14:1733. [PMID: 36977673 PMCID: PMC10044120 DOI: 10.1038/s41467-023-37254-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [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: 07/08/2022] [Accepted: 03/08/2023] [Indexed: 03/30/2023] Open
Abstract
Direct-acting antivirals are needed to combat coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). The papain-like protease (PLpro) domain of Nsp3 from SARS-CoV-2 is essential for viral replication. In addition, PLpro dysregulates the host immune response by cleaving ubiquitin and interferon-stimulated gene 15 protein from host proteins. As a result, PLpro is a promising target for inhibition by small-molecule therapeutics. Here we design a series of covalent inhibitors by introducing a peptidomimetic linker and reactive electrophile onto analogs of the noncovalent PLpro inhibitor GRL0617. The most potent compound inhibits PLpro with kinact/KI = 9,600 M-1 s-1, achieves sub-μM EC50 values against three SARS-CoV-2 variants in mammalian cell lines, and does not inhibit a panel of human deubiquitinases (DUBs) at >30 μM concentrations of inhibitor. An X-ray co-crystal structure of the compound bound to PLpro validates our design strategy and establishes the molecular basis for covalent inhibition and selectivity against structurally similar human DUBs. These findings present an opportunity for further development of covalent PLpro inhibitors.
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Affiliation(s)
- Brian C Sanders
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
| | - Suman Pokhrel
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA
- Biological Sciences Division, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Audrey D Labbe
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | | | - Connor J Cooper
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | | | - Gwyndalyn Phillips
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Kevin L Weiss
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Qiu Zhang
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Hugh O'Neill
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Manat Kaur
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Jurgen G Schmidt
- B-11 Bioenergy and Biome Sciences, Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Walter Reichard
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Surekha Surendranathan
- Regional Biocontainment Laboratory, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Jyothi Parvathareddy
- Regional Biocontainment Laboratory, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Lexi Phillips
- Institute for Antiviral Research, Department of Animal, Dairy, and Veterinary Sciences, Utah State University, Logan, UT, USA
| | | | | | - Desigan Kumaran
- Biology Department, Brookhaven National Laboratory, Upton, NY, USA
| | - Babak Andi
- Center for BioMolecular Structure, National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, USA
| | - Gyorgy Babnigg
- Center for Structural Genomics of Infectious Diseases, Consortium for Advanced Science and Engineering, University of Chicago, Chicago, IL, USA
- Biosciences Division, Argonne National Laboratory, Argonne, IL, USA
| | - Nigel W Moriarty
- Molecular Biosciences and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Paul D Adams
- Molecular Biosciences and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Bioengineering, University of California, Berkeley, CA, USA
| | - Andrzej Joachimiak
- Center for Structural Genomics of Infectious Diseases, Consortium for Advanced Science and Engineering, University of Chicago, Chicago, IL, USA
- Structural Biology Center, X-ray Science Division, Argonne National Laboratory, Argonne, IL, USA
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA
| | - Brett L Hurst
- Institute for Antiviral Research, Department of Animal, Dairy, and Veterinary Sciences, Utah State University, Logan, UT, USA
| | | | | | - Colleen B Jonsson
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Lori Ferrins
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, USA
| | - Soichi Wakatsuki
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA.
- Stanford Synchrotron Radiation Lightsource, Menlo Park, CA, USA.
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA.
| | - Stephanie Galanie
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
- Department of Process Research and Development, Merck & Co., Inc., Rahway, NJ, USA
| | - Martha S Head
- Joint Institute for Biological Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, USA
- Computing and Computational Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN, USA
- Computational and Data Sciences, Center for Research Acceleration by Digital Innovation, Amgen, Inc., Thosand Oaks, CA, USA
| | - Jerry M Parks
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
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3
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Moniruzzaman M, Cooper CJ, Uddin MR, Walker JK, Parks JM, Zgurskaya HI. Analysis of Orthogonal Efflux and Permeation Properties of Compounds Leads to the Discovery of New Efflux Pump Inhibitors. ACS Infect Dis 2022; 8:2149-2160. [PMID: 36070489 PMCID: PMC9942517 DOI: 10.1021/acsinfecdis.2c00263] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Optimization of compound permeation into Gram-negative bacteria is one of the most challenging tasks in the development of antibacterial agents. Two permeability barriers─the passive diffusion barrier of the outer membrane (OM) and active drug efflux─act synergistically to protect cells from the antibacterial action of compounds. In Escherichia coli (E. coli) and relatives, these two barriers sieve compounds based on different physicochemical properties that are defined by their interactions with OM porins and efflux pumps, respectively. In this study, we critically tested the hypothesis that the best substrates and inhibitors of efflux pumps are compounds that can effectively permeate the OM and are available at relatively high concentrations in the periplasm. For this purpose, we filtered a large subset of the ZINC15 database of commercially available compounds for compounds containing a primary amine, a chemical feature known to facilitate the uptake through E. coli general porins. The assembled library was screened by ensemble docking to AcrA, the periplasmic component of the AcrAB-TolC efflux pump, followed by experimental testing of the top predicted binders for antibacterial activities, efflux recognition, and inhibition. We found that the filtered primary amine library is a rich source of compounds with efflux-inhibiting activities and identified efflux pump inhibitors with novel chemical scaffolds effective against E. coli AcrAB-TolC and efflux pumps of multidrug-resistant clinical isolates of Acinetobacter baumannii. However, primary amines are not required for the recognition of compounds by efflux pumps and their efflux-inhibitory activities.
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Affiliation(s)
- Mohammad Moniruzzaman
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73072, United States
| | - Connor J Cooper
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Muhammad R Uddin
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73072, United States
| | - John K Walker
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, Missouri 63110, United States
| | - Jerry M Parks
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Helen I Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73072, United States
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4
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Leus IV, Weeks JW, Bonifay V, Shen Y, Yang L, Cooper CJ, Nash D, Duerfeldt AS, Smith JC, Parks JM, Rybenkov VV, Zgurskaya HI. Property space mapping of Pseudomonas aeruginosa permeability to small molecules. Sci Rep 2022; 12:8220. [PMID: 35581346 PMCID: PMC9114115 DOI: 10.1038/s41598-022-12376-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 05/10/2022] [Indexed: 02/03/2023] Open
Abstract
Two membrane cell envelopes act as selective permeability barriers in Gram-negative bacteria, protecting cells against antibiotics and other small molecules. Significant efforts are being directed toward understanding how small molecules permeate these barriers. In this study, we developed an approach to analyze the permeation of compounds into Gram-negative bacteria and applied it to Pseudomonas aeruginosa, an important human pathogen notorious for resistance to multiple antibiotics. The approach uses mass spectrometric measurements of accumulation of a library of structurally diverse compounds in four isogenic strains of P. aeruginosa with varied permeability barriers. We further developed a machine learning algorithm that generates a deterministic classification model with minimal synonymity between the descriptors. This model predicted good permeators into P. aeruginosa with an accuracy of 89% and precision above 58%. The good permeators are broadly distributed in the property space and can be mapped to six distinct regions representing diverse chemical scaffolds. We posit that this approach can be used for more detailed mapping of the property space and for rational design of compounds with high Gram-negative permeability.
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Affiliation(s)
- Inga V Leus
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK, 73019, USA
| | - Jon W Weeks
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK, 73019, USA
| | - Vincent Bonifay
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK, 73019, USA
| | - Yue Shen
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Liang Yang
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK, 73019, USA
| | - Connor J Cooper
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Dinesh Nash
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK, 73019, USA
| | - Adam S Duerfeldt
- Department of Medicinal Chemistry, University of Minnesota, 717 Delaware St. SE, Minneapolis, MN, 55414, USA
| | - Jeremy C Smith
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN, 37996, USA
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Jerry M Parks
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Valentin V Rybenkov
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK, 73019, USA.
| | - Helen I Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, OK, 73019, USA.
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5
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Semchonok DA, Mondal J, Cooper CJ, Schlum K, Li M, Amin M, Sorzano CO, Ramírez-Aportela E, Kastritis PL, Boekema EJ, Guskov A, Bruce BD. Cryo-EM structure of a tetrameric photosystem I from Chroococcidiopsis TS-821, a thermophilic, unicellular, non-heterocyst-forming cyanobacterium. Plant Commun 2022; 3:100248. [PMID: 35059628 PMCID: PMC8760143 DOI: 10.1016/j.xplc.2021.100248] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 09/03/2021] [Accepted: 10/08/2021] [Indexed: 05/19/2023]
Abstract
Photosystem I (PSI) is one of two photosystems involved in oxygenic photosynthesis. PSI of cyanobacteria exists in monomeric, trimeric, and tetrameric forms, in contrast to the strictly monomeric form of PSI in plants and algae. The tetrameric organization raises questions about its structural, physiological, and evolutionary significance. Here we report the ∼3.72 Å resolution cryo-electron microscopy structure of tetrameric PSI from the thermophilic, unicellular cyanobacterium Chroococcidiopsis sp. TS-821. The structure resolves 44 subunits and 448 cofactor molecules. We conclude that the tetramer is arranged via two different interfaces resulting from a dimer-of-dimers organization. The localization of chlorophyll molecules permits an excitation energy pathway within and between adjacent monomers. Bioinformatics analysis reveals conserved regions in the PsaL subunit that correlate with the oligomeric state. Tetrameric PSI may function as a key evolutionary step between the trimeric and monomeric forms of PSI organization in photosynthetic organisms.
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Affiliation(s)
- Dmitry A. Semchonok
- Groningen Biomolecular Sciences & Biotechnology Institute, University of Groningen, Groningen, the Netherlands
| | - Jyotirmoy Mondal
- Biochemistry & Cellular and Molecular Biology Department, University of Tennessee, Knoxville, TN, USA
| | - Connor J. Cooper
- Program in Genome Science and Technology, University of Tennessee, Knoxville, TN, USA
| | - Katrina Schlum
- Program in Genome Science and Technology, University of Tennessee, Knoxville, TN, USA
| | - Meng Li
- Biochemistry & Cellular and Molecular Biology Department, University of Tennessee, Knoxville, TN, USA
- Bredesen Center for Interdisciplinary Research & Education, University of Tennessee, Knoxville, TN, USA
| | - Muhamed Amin
- Department of Sciences, University College Groningen, Groningen, the Netherlands
| | - Carlos O.S. Sorzano
- Biocomputing Unit, National Center for Biotechnology (CSIC), Darwin 3, Campus Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
- Universidad CEU San Pablo, Campus Urb. Montepríncipe, Boadilla del Monte, 28668 Madrid, Spain
| | - Erney Ramírez-Aportela
- Biocomputing Unit, National Center for Biotechnology (CSIC), Darwin 3, Campus Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
| | - Panagiotis L. Kastritis
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
| | - Egbert J. Boekema
- Groningen Biomolecular Sciences & Biotechnology Institute, University of Groningen, Groningen, the Netherlands
| | - Albert Guskov
- Groningen Biomolecular Sciences & Biotechnology Institute, University of Groningen, Groningen, the Netherlands
| | - Barry D. Bruce
- Biochemistry & Cellular and Molecular Biology Department, University of Tennessee, Knoxville, TN, USA
- Program in Genome Science and Technology, University of Tennessee, Knoxville, TN, USA
- Bredesen Center for Interdisciplinary Research & Education, University of Tennessee, Knoxville, TN, USA
- Microbiology Department, University of Tennessee, Knoxville, TN, USA
- Corresponding author
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6
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Gumbart JC, Ferreira JL, Hwang H, Hazel AJ, Cooper CJ, Parks JM, Smith JC, Zgurskaya HI, Beeby M. Lpp positions peptidoglycan at the AcrA-TolC interface in the AcrAB-TolC multidrug efflux pump. Biophys J 2021; 120:3973-3982. [PMID: 34411576 DOI: 10.1016/j.bpj.2021.08.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 07/02/2021] [Accepted: 08/11/2021] [Indexed: 01/07/2023] Open
Abstract
The multidrug efflux pumps of Gram-negative bacteria are a class of complexes that span the periplasm, coupling both the inner and outer membranes to expel toxic molecules. The best-characterized example of these tripartite pumps is the AcrAB-TolC complex of Escherichia coli. However, how the complex interacts with the peptidoglycan (PG) cell wall, which is anchored to the outer membrane (OM) by Braun's lipoprotein (Lpp), is still largely unknown. In this work, we present molecular dynamics simulations of a complete, atomistic model of the AcrAB-TolC complex with the inner membrane, OM, and PG layers all present. We find that the PG localizes to the junction of AcrA and TolC, in agreement with recent cryo-tomography data. Free-energy calculations reveal that the positioning of PG is determined by the length and conformation of multiple Lpp copies anchoring it to the OM. The distance between the PG and OM measured in cryo-electron microscopy images of wild-type E. coli also agrees with the simulation-derived spacing. Sequence analysis of AcrA suggests a conserved role for interactions with PG in the assembly and stabilization of efflux pumps, one that may extend to other trans-envelope complexes as well.
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Affiliation(s)
- James C Gumbart
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia.
| | - Josie L Ferreira
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Hyea Hwang
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia
| | - Anthony J Hazel
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia
| | - Connor J Cooper
- UT/ORNL Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee
| | - Jerry M Parks
- UT/ORNL Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee
| | - Jeremy C Smith
- UT/ORNL Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee; Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee
| | - Helen I Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma
| | - Morgan Beeby
- Department of Life Sciences, Imperial College London, London, United Kingdom
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7
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D’Cunha N, Moniruzzaman M, Haynes K, Malloci G, Cooper CJ, Margiotta E, Vargiu AV, Uddin MR, Leus IV, Cao F, Parks JM, Rybenkov VV, Ruggerone P, Zgurskaya HI, Walker JK. Mechanistic Duality of Bacterial Efflux Substrates and Inhibitors: Example of Simple Substituted Cinnamoyl and Naphthyl Amides. ACS Infect Dis 2021; 7:2650-2665. [PMID: 34379382 DOI: 10.1021/acsinfecdis.1c00100] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [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: 11/28/2022]
Abstract
Antibiotic resistance poses an immediate and growing threat to human health. Multidrug efflux pumps are promising targets for overcoming antibiotic resistance with small-molecule therapeutics. Previously, we identified a diaminoquinoline acrylamide, NSC-33353, as a potent inhibitor of the AcrAB-TolC efflux pump in Escherichia coli. This inhibitor potentiates the antibacterial activities of novobiocin and erythromycin upon binding to the membrane fusion protein AcrA. It is also a substrate for efflux and lacks appreciable intrinsic antibacterial activity of its own in wild-type cells. Here, we have modified the substituents of the cinnamoyl group of NSC-33353, giving rise to analogs that retain the ability to inhibit efflux, lost the features of the efflux substrates, and gained antibacterial activity in wild-type cells. The replacement of the cinnamoyl group with naphthyl isosteres generated compounds that lack antibacterial activity but are both excellent efflux pump inhibitors and substrates. Surprisingly, these inhibitors potentiate the antibacterial activity of novobiocin but not erythromycin. Surface plasmon resonance experiments and molecular docking suggest that the replacement of the cinnamoyl group with naphthyl shifts the affinity of the compounds away from AcrA to the AcrB transporter, making them better efflux substrates and changing their mechanism of inhibition. These results provide new insights into the duality of efflux substrate/inhibitor features in chemical scaffolds that will facilitate the development of new efflux pump inhibitors.
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Affiliation(s)
- Napoleon D’Cunha
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, Missouri 63110, United States
| | - Mohammad Moniruzzaman
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73072, United States
| | - Keith Haynes
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, Missouri 63110, United States
| | - Giuliano Malloci
- Department of Physics, University of Cagliari, Monserrato, Cagliari 09042, Italy
| | - Connor J. Cooper
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Tennessee 37996, United States
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Enrico Margiotta
- Department of Physics, University of Cagliari, Monserrato, Cagliari 09042, Italy
| | - Attilio V. Vargiu
- Department of Physics, University of Cagliari, Monserrato, Cagliari 09042, Italy
| | - Muhammad R. Uddin
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73072, United States
| | - Inga V. Leus
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73072, United States
| | - Feng Cao
- John Cochran Division, Department of Veteran Affairs Medical Center, St. Louis, Missouri 63106, United States
| | - Jerry M. Parks
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Valentin V. Rybenkov
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73072, United States
| | - Paolo Ruggerone
- Department of Physics, University of Cagliari, Monserrato, Cagliari 09042, Italy
| | - Helen I. Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma 73072, United States
| | - John K. Walker
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, Missouri 63110, United States
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8
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Mishra SK, Cooper CJ, Parks JM, Mitchell JC. Hotspot Coevolution Is a Key Identifier of Near-Native Protein Complexes. J Phys Chem B 2021; 125:6058-6067. [PMID: 34077660 DOI: 10.1021/acs.jpcb.0c11525] [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: 11/30/2022]
Abstract
Protein-protein interactions play a key role in mediating numerous biological functions, with more than half the proteins in living organisms existing as either homo- or hetero-oligomeric assemblies. Protein subunits that form oligomers minimize the free energy of the complex, but exhaustive computational search-based docking methods have not comprehensively addressed the challenge of distinguishing a natively bound complex from non-native forms. Current protein docking approaches address this problem by sampling multiple binding modes in proteins and scoring each mode, with the lowest-energy (or highest scoring) binding mode being regarded as a near-native complex. However, high-scoring modes often match poorly with the true bound form, suggesting a need for improvement of the scoring function. In this study, we propose a scoring function, KFC-E, that accounts for both conservation and coevolution of putative binding hotspot residues at protein-protein interfaces. We tested KFC-E on four benchmark sets of unbound examples and two benchmark sets of bound examples, with the results demonstrating a clear improvement over scores that examine conservation and coevolution across the entire interface.
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Affiliation(s)
- Sambit K Mishra
- Biosciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831-6038, United States
| | - Connor J Cooper
- Biosciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831-6038, United States
| | - Jerry M Parks
- Biosciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831-6038, United States
| | - Julie C Mitchell
- Biosciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831-6038, United States
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9
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Lian P, Mou Z, Cooper CJ, Johnston RC, Brooks SC, Gu B, Govind N, Jonsson S, Parks JM. Mechanistic Investigation of Dimethylmercury Formation Mediated by a Sulfide Mineral Surface. J Phys Chem A 2021; 125:5397-5405. [PMID: 34114820 DOI: 10.1021/acs.jpca.1c04014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mercury (Hg) pollution is a global environmental problem. The abiotic formation of dimethylmercury (DMeHg) from monomethylmercury (MMeHg) may account for a large portion of DMeHg in oceans. Previous experimental work has shown that abiotic formation of DMeHg from MMeHg can be facilitated by reduced sulfur groups on sulfide mineral surfaces. In that work, a mechanism was proposed in which neighboring MMeHg moieties bound to sulfide sites on a mineral surface react through an SN2-type mechanism to form DMeHg and incorporate the remaining Hg atoms into the mineral surface. Here, we perform density functional theory calculations to explore the mechanisms of DMeHg formation on the 110 surface of a CdS(s) (hawleyite) nanoparticle. We show that coordination of MMeHg substituents to adjacent reduced sulfur groups protruding from the surface indeed facilitates DMeHg formation and that the reaction proceeds through direct transmethylation from one MMeHg substituent to another. Coordination of Hg by multiple S atoms provides a transition-state stabilization and activates a C-Hg bond for methyl transfer. In addition, solvation effects play an important role in the surface reconstruction of the nanoparticle and in decreasing the energetic barrier for DMeHg formation relative to the corresponding reaction in vacuo.
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Affiliation(s)
- Peng Lian
- UT/ORNL Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, United States.,Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Zhongyu Mou
- UT/ORNL Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, United States
| | - Connor J Cooper
- UT/ORNL Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, United States
| | - Ryne C Johnston
- UT/ORNL Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, United States
| | - Scott C Brooks
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Baohua Gu
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Niranjan Govind
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Sofi Jonsson
- Department of Environmental Science, Stockholm University, 106 91 Stockholm, Sweden
| | - Jerry M Parks
- UT/ORNL Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, United States.,Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996, United States
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10
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Ajina R, Malchiodi ZX, Fitzgerald AA, Zuo A, Wang S, Moussa M, Cooper CJ, Shen Y, Johnson QR, Parks JM, Smith JC, Catalfamo M, Fertig EJ, Jablonski SA, Weiner LM. Antitumor T-cell Immunity Contributes to Pancreatic Cancer Immune Resistance. Cancer Immunol Res 2021; 9:386-400. [PMID: 33509790 DOI: 10.1158/2326-6066.cir-20-0272] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 10/27/2020] [Accepted: 01/26/2021] [Indexed: 12/14/2022]
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is the third leading cause of cancer death in the United States. Pancreatic tumors are minimally infiltrated by T cells and are largely refractory to immunotherapy. Accordingly, the role of T-cell immunity in pancreatic cancer has been somewhat overlooked. Here, we hypothesized that immune resistance in pancreatic cancer was induced in response to antitumor T-cell immune responses and that understanding how pancreatic tumors respond to immune attack may facilitate the development of more effective therapeutic strategies. We now provide evidence that T-cell-dependent host immune responses induce a PDAC-derived myeloid mimicry phenomenon and stimulate immune resistance. Three KPC mouse models of pancreatic cancer were used: the mT3-2D (Kras+/LSL-G12D; Trp53+/LSL-R172H; Pdx1-Cre) subcutaneous and orthotopic models, as well as the KP1 (p48-CRE/LSL-Kras/Trp53 flox/flox ) subcutaneous model. KPC cancer cells were grown in immunocompetent and immunodeficient C57BL/6 mice and analyzed to determine the impact of adaptive immunity on malignant epithelial cells, as well as on whole tumors. We found that induced T-cell antitumor immunity, via signal transducer and activator of transcription 1 (STAT1), stimulated malignant epithelial pancreatic cells to induce the expression of genes typically expressed by myeloid cells and altered intratumoral immunosuppressive myeloid cell profiles. Targeting the Janus Kinase (JAK)/STAT signaling pathway using the FDA-approved drug ruxolitinib overcame these tumor-protective responses and improved anti-PD-1 therapeutic efficacy. These findings provide future directions for treatments that specifically disable this mechanism of resistance in PDAC.
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Affiliation(s)
- Reham Ajina
- Department of Oncology and Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, District of Columbia
| | - Zoe X Malchiodi
- Department of Oncology and Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, District of Columbia
| | - Allison A Fitzgerald
- Department of Oncology and Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, District of Columbia
| | - Annie Zuo
- Department of Oncology and Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, District of Columbia
| | - Shangzi Wang
- Department of Oncology and Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, District of Columbia
| | - Maha Moussa
- Department of Microbiology and Immunology, Georgetown University Medical Center, Washington, District of Columbia
| | - Connor J Cooper
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Tennessee
| | - Yue Shen
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Tennessee
| | - Quentin R Johnson
- Department of Chemistry and Biochemistry, Berry College, Mount Berry, Georgia
| | - Jerry M Parks
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Tennessee.,Department of Chemistry and Biochemistry, Berry College, Mount Berry, Georgia
| | - Jeremy C Smith
- Department of Chemistry and Biochemistry, Berry College, Mount Berry, Georgia.,Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee
| | - Marta Catalfamo
- Department of Microbiology and Immunology, Georgetown University Medical Center, Washington, District of Columbia
| | - Elana J Fertig
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland.,Department of Applied Mathematics and Statistics, Johns Hopkins University Whiting School of Engineering, Baltimore, Maryland.,Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Sandra A Jablonski
- Department of Oncology and Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, District of Columbia
| | - Louis M Weiner
- Department of Oncology and Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, District of Columbia.
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11
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Mou Z, Eakes J, Cooper CJ, Foster CM, Standaert RF, Podar M, Doktycz MJ, Parks JM. Machine learning‐based prediction of enzyme substrate scope: Application to bacterial nitrilases. Proteins 2020; 89:336-347. [DOI: 10.1002/prot.26019] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 09/02/2020] [Accepted: 10/17/2020] [Indexed: 01/11/2023]
Affiliation(s)
- Zhongyu Mou
- Biosciences Division Oak Ridge National Laboratory Oak Ridge Tennessee USA
| | - Jason Eakes
- Biosciences Division Oak Ridge National Laboratory Oak Ridge Tennessee USA
| | - Connor J. Cooper
- Graduate School of Genome Science and Technology University of TennesseeWalters Life Science Knoxville Tennessee USA
| | - Carmen M. Foster
- Biosciences Division Oak Ridge National Laboratory Oak Ridge Tennessee USA
| | | | - Mircea Podar
- Biosciences Division Oak Ridge National Laboratory Oak Ridge Tennessee USA
| | - Mitchel J. Doktycz
- Biosciences Division Oak Ridge National Laboratory Oak Ridge Tennessee USA
- Graduate School of Genome Science and Technology University of TennesseeWalters Life Science Knoxville Tennessee USA
| | - Jerry M. Parks
- Biosciences Division Oak Ridge National Laboratory Oak Ridge Tennessee USA
- Graduate School of Genome Science and Technology University of TennesseeWalters Life Science Knoxville Tennessee USA
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12
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Acharya A, Agarwal R, Baker M, Baudry J, Bhowmik D, Boehm S, Byler KG, Coates L, Chen SY, Cooper CJ, Demerdash O, Daidone I, Eblen JD, Ellingson S, Forli S, Glaser J, Gumbart JC, Gunnels J, Hernandez O, Irle S, Larkin J, Lawrence TJ, LeGrand S, Liu SH, Mitchell JC, Park G, Parks JM, Pavlova A, Petridis L, Poole D, Pouchard L, Ramanathan A, Rogers D, Santos-Martins D, Scheinberg A, Sedova A, Shen S, Smith JC, Smith MD, Soto C, Tsaris A, Thavappiragasam M, Tillack AF, Vermaas JV, Vuong VQ, Yin J, Yoo S, Zahran M, Zanetti-Polzi L. Supercomputer-Based Ensemble Docking Drug Discovery Pipeline with Application to Covid-19. ChemRxiv 2020:12725465. [PMID: 33200117 PMCID: PMC7668744 DOI: 10.26434/chemrxiv.12725465] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Revised: 07/29/2020] [Indexed: 01/18/2023]
Abstract
We present a supercomputer-driven pipeline for in-silico drug discovery using enhanced sampling molecular dynamics (MD) and ensemble docking. We also describe preliminary results obtained for 23 systems involving eight protein targets of the proteome of SARS CoV-2. THe MD performed is temperature replica-exchange enhanced sampling, making use of the massively parallel supercomputing on the SUMMIT supercomputer at Oak Ridge National Laboratory, with which more than 1ms of enhanced sampling MD can be generated per day. We have ensemble docked repurposing databases to ten configurations of each of the 23 SARS CoV-2 systems using AutoDock Vina. We also demonstrate that using Autodock-GPU on SUMMIT, it is possible to perform exhaustive docking of one billion compounds in under 24 hours. Finally, we discuss preliminary results and planned improvements to the pipeline, including the use of quantum mechanical (QM), machine learning, and AI methods to cluster MD trajectories and rescore docking poses.
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Affiliation(s)
- A Acharya
- School of Physics, Georgia Institute of Technology, Atlanta, GA 30332
| | - R Agarwal
- UT/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, TN, 37830
- The University of Tennessee, Knoxville. Department of Biochemistry & Cellular and Molecular Biology, 309 Ken and Blaire Mossman Bldg. 1311 Cumberland Avenue Knoxville, TN, 37996
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN, 37996
| | - M Baker
- Computer Science and Mathematics Division, Oak Ridge National Lab, Oak Ridge, TN 37830
| | - J Baudry
- The University of Alabama in Huntsville, Department of Biological Sciences. 301 Sparkman Drive, Huntsville, AL 35899
| | - D Bhowmik
- Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831
| | - S Boehm
- Computer Science and Mathematics Division, Oak Ridge National Lab, Oak Ridge, TN 37830
| | - K G Byler
- The University of Alabama in Huntsville, Department of Biological Sciences. 301 Sparkman Drive, Huntsville, AL 35899
| | - L Coates
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831
| | - S Y Chen
- Computational Science Initiative, Brookhaven National Laboratory, Upton, NY 11973
| | - C J Cooper
- UT/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, TN, 37830
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN, 37996
| | - O Demerdash
- Biosciences Division, Oak Ridge National Lab, Oak Ridge, TN 37830
| | - I Daidone
- Department of Physical and Chemical Sciences, University of L'Aquila, I-67010 L'Aquila, Italy
| | - J D Eblen
- UT/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, TN, 37830
- The University of Tennessee, Knoxville. Department of Biochemistry & Cellular and Molecular Biology, 309 Ken and Blaire Mossman Bldg. 1311 Cumberland Avenue Knoxville, TN, 37996
| | - S Ellingson
- University of Kentucky, Division of Biomedical Informatics, College of Medicine, UK Medical Center MN 150, Lexington KY, 40536
| | - S Forli
- Scripps Research, La Jolla, CA, 92037
| | - J Glaser
- National Center for Computational Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37830
| | - J C Gumbart
- School of Physics, Georgia Institute of Technology, Atlanta, GA 30332
| | - J Gunnels
- HPC Engineering, Amazon Web Services, Seattle, WA 98121
| | - O Hernandez
- Computer Science and Mathematics Division, Oak Ridge National Lab, Oak Ridge, TN 37830
| | - S Irle
- Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831
- Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, TN 37996
| | - J Larkin
- NVIDIA Corporation, Santa Clara, CA 95051
| | - T J Lawrence
- Biosciences Division, Oak Ridge National Lab, Oak Ridge, TN 37830
| | - S LeGrand
- NVIDIA Corporation, Santa Clara, CA 95051
| | - S-H Liu
- UT/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, TN, 37830
- The University of Tennessee, Knoxville. Department of Biochemistry & Cellular and Molecular Biology, 309 Ken and Blaire Mossman Bldg. 1311 Cumberland Avenue Knoxville, TN, 37996
| | - J C Mitchell
- Biosciences Division, Oak Ridge National Lab, Oak Ridge, TN 37830
| | - G Park
- Computational Science Initiative, Brookhaven National Laboratory, Upton, NY 11973
| | - J M Parks
- UT/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, TN, 37830
- The University of Tennessee, Knoxville. Department of Biochemistry & Cellular and Molecular Biology, 309 Ken and Blaire Mossman Bldg. 1311 Cumberland Avenue Knoxville, TN, 37996
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN, 37996
| | - A Pavlova
- School of Physics, Georgia Institute of Technology, Atlanta, GA 30332
| | - L Petridis
- UT/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, TN, 37830
- The University of Tennessee, Knoxville. Department of Biochemistry & Cellular and Molecular Biology, 309 Ken and Blaire Mossman Bldg. 1311 Cumberland Avenue Knoxville, TN, 37996
| | - D Poole
- NVIDIA Corporation, Santa Clara, CA 95051
| | - L Pouchard
- Computational Science Initiative, Brookhaven National Laboratory, Upton, NY 11973
| | - A Ramanathan
- Data Science and Learning Division, Argonne National Lab, Lemont, IL 60439
| | - D Rogers
- National Center for Computational Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37830
| | | | | | - A Sedova
- Biosciences Division, Oak Ridge National Lab, Oak Ridge, TN 37830
| | - S Shen
- UT/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, TN, 37830
- The University of Tennessee, Knoxville. Department of Biochemistry & Cellular and Molecular Biology, 309 Ken and Blaire Mossman Bldg. 1311 Cumberland Avenue Knoxville, TN, 37996
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN, 37996
| | - J C Smith
- UT/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, TN, 37830
- The University of Tennessee, Knoxville. Department of Biochemistry & Cellular and Molecular Biology, 309 Ken and Blaire Mossman Bldg. 1311 Cumberland Avenue Knoxville, TN, 37996
| | - M D Smith
- UT/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, TN, 37830
- The University of Tennessee, Knoxville. Department of Biochemistry & Cellular and Molecular Biology, 309 Ken and Blaire Mossman Bldg. 1311 Cumberland Avenue Knoxville, TN, 37996
| | - C Soto
- Computational Science Initiative, Brookhaven National Laboratory, Upton, NY 11973
| | - A Tsaris
- National Center for Computational Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37830
| | | | | | - J V Vermaas
- National Center for Computational Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37830
| | - V Q Vuong
- Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831
- Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, TN 37996
| | - J Yin
- National Center for Computational Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37830
| | - S Yoo
- Computational Science Initiative, Brookhaven National Laboratory, Upton, NY 11973
| | - M Zahran
- Department of Biological Sciences, New York City College of Technology, The City University of New York (CUNY), Brooklyn, NY 11201
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13
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Cooper CJ, Zheng K, Rush KW, Johs A, Sanders BC, Pavlopoulos GA, Kyrpides NC, Podar M, Ovchinnikov S, Ragsdale SW, Parks JM. Structure determination of the HgcAB complex using metagenome sequence data: insights into microbial mercury methylation. Commun Biol 2020; 3:320. [PMID: 32561885 PMCID: PMC7305189 DOI: 10.1038/s42003-020-1047-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [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: 01/27/2020] [Accepted: 05/27/2020] [Indexed: 11/09/2022] Open
Abstract
Bacteria and archaea possessing the hgcAB gene pair methylate inorganic mercury (Hg) to form highly toxic methylmercury. HgcA consists of a corrinoid binding domain and a transmembrane domain, and HgcB is a dicluster ferredoxin. However, their detailed structure and function have not been thoroughly characterized. We modeled the HgcAB complex by combining metagenome sequence data mining, coevolution analysis, and Rosetta structure calculations. In addition, we overexpressed HgcA and HgcB in Escherichia coli, confirmed spectroscopically that they bind cobalamin and [4Fe-4S] clusters, respectively, and incorporated these cofactors into the structural model. Surprisingly, the two domains of HgcA do not interact with each other, but HgcB forms extensive contacts with both domains. The model suggests that conserved cysteines in HgcB are involved in shuttling HgII, methylmercury, or both. These findings refine our understanding of the mechanism of Hg methylation and expand the known repertoire of corrinoid methyltransferases in nature. Connor J. Cooper et al. expressed HgcA and HgcB in Escherichia coli and modeled the structure of the HgcAB complex by combining metagenome sequence data, coevolution analysis, and ab initio structure calculations. This study provides insights into the biochemical mechanism of mercury (Hg) methylation.
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Affiliation(s)
- Connor J Cooper
- Graduate School of Genome Science and Technology, University of Tennessee, F225 Walters Life Science, Knoxville, TN, 37996, USA.,Biosciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN, 37831-6038, USA
| | - Kaiyuan Zheng
- Department of Biological Chemistry, University of Michigan Medical School, 1150 West Medical Center Drive, Ann Arbor, MI, 48109-0606, USA
| | - Katherine W Rush
- Department of Biological Chemistry, University of Michigan Medical School, 1150 West Medical Center Drive, Ann Arbor, MI, 48109-0606, USA
| | - Alexander Johs
- Environmental Sciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN, 37831-6038, USA
| | - Brian C Sanders
- Biosciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN, 37831-6038, USA
| | - Georgios A Pavlopoulos
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA, 94720, USA.,Institute for Fundamental Biomedical Research, Biomedical Science Research Center "Alexander Fleming", 34 Fleming Street, 16672, Vari, Greece
| | - Nikos C Kyrpides
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA, 94720, USA.,Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory Berkeley, California, USA
| | - Mircea Podar
- Graduate School of Genome Science and Technology, University of Tennessee, F225 Walters Life Science, Knoxville, TN, 37996, USA.,Biosciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN, 37831-6038, USA
| | - Sergey Ovchinnikov
- John Harvard Distinguished Science Fellowship Program, Harvard University, Cambridge, MA, 02138, USA
| | - Stephen W Ragsdale
- Department of Biological Chemistry, University of Michigan Medical School, 1150 West Medical Center Drive, Ann Arbor, MI, 48109-0606, USA
| | - Jerry M Parks
- Graduate School of Genome Science and Technology, University of Tennessee, F225 Walters Life Science, Knoxville, TN, 37996, USA. .,Biosciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN, 37831-6038, USA.
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14
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Green AT, Moniruzzaman M, Cooper CJ, Walker JK, Smith JC, Parks JM, Zgurskaya HI. Discovery of multidrug efflux pump inhibitors with a novel chemical scaffold. Biochim Biophys Acta Gen Subj 2020; 1864:129546. [PMID: 32032658 DOI: 10.1016/j.bbagen.2020.129546] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 01/21/2020] [Accepted: 01/30/2020] [Indexed: 12/12/2022]
Abstract
Multidrug efflux is a major contributor to antibiotic resistance in Gram-negative bacterial pathogens. Inhibition of multidrug efflux pumps is a promising approach for reviving the efficacy of existing antibiotics. Previously, inhibitors targeting both the efflux transporter AcrB and the membrane fusion protein AcrA in the Escherichia coli AcrAB-TolC efflux pump were identified. Here we use existing physicochemical property guidelines to generate a filtered library of compounds for computational docking. We then experimentally test the top candidate coumpounds using in vitro binding assays and in vivo potentiation assays in bacterial strains with controllable permeability barriers. We thus identify a new class of inhibitors of E. coli AcrAB-TolC. Six molecules with a shared scaffold were found to potentiate the antimicrobial activity of erythromycin and novobiocin in hyperporinated E. coli cells. Importantly, these six molecules were also active in wild-type strains of both Acinetobacter baumannii and Klebsiella pneumoniae, potentiating the activity of erythromycin and novobiocin up to 8-fold.
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Affiliation(s)
- Adam T Green
- UT/ORNL Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA; Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Mohammad Moniruzzaman
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019, USA
| | - Connor J Cooper
- UT/ORNL Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA; Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN, 37996, USA
| | - John K Walker
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine and the Henry and Amelia Nasrallah Center for Neuroscience, Saint Louis, MO, 63104, USA
| | - Jeremy C Smith
- UT/ORNL Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA; Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN, 37996, USA; Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Jerry M Parks
- UT/ORNL Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA; Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN, 37996, USA.
| | - Helen I Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019, USA.
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15
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Close DM, Cooper CJ, Wang X, Chirania P, Gupta M, Ossyra JR, Giannone RJ, Engle N, Tschaplinski TJ, Smith JC, Hedstrom L, Parks JM, Michener JK. Horizontal transfer of a pathway for coumarate catabolism unexpectedly inhibits purine nucleotide biosynthesis. Mol Microbiol 2019; 112:1784-1797. [PMID: 31532038 DOI: 10.1111/mmi.14393] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2019] [Indexed: 11/28/2022]
Abstract
A microbe's ecological niche and biotechnological utility are determined by its specific set of co-evolved metabolic pathways. The acquisition of new pathways, through horizontal gene transfer or genetic engineering, can have unpredictable consequences. Here we show that two different pathways for coumarate catabolism failed to function when initially transferred into Escherichia coli. Using laboratory evolution, we elucidated the factors limiting activity of the newly acquired pathways and the modifications required to overcome these limitations. Both pathways required host mutations to enable effective growth with coumarate, but the necessary mutations differed. In one case, a pathway intermediate inhibited purine nucleotide biosynthesis, and this inhibition was relieved by single amino acid replacements in IMP dehydrogenase. A strain that natively contains this coumarate catabolism pathway, Acinetobacter baumannii, is resistant to inhibition by the relevant intermediate, suggesting that natural pathway transfers have faced and overcome similar challenges. Molecular dynamics simulation of the wild type and a representative single-residue mutant provide insight into the structural and dynamic changes that relieve inhibition. These results demonstrate how deleterious interactions can limit pathway transfer, that these interactions can be traced to specific molecular interactions between host and pathway, and how evolution or engineering can alleviate these limitations.
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Affiliation(s)
- Dan M Close
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Connor J Cooper
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Xingyou Wang
- Graduate Program in Chemistry, Brandeis University, 415 South Street, Waltham, MA, 02454, USA
| | - Payal Chirania
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN, 37996, USA.,Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Madhulika Gupta
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - John R Ossyra
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Richard J Giannone
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA.,BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA.,Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Nancy Engle
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.,BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA.,Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Timothy J Tschaplinski
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.,BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA.,Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Jeremy C Smith
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.,Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee Knoxville, Knoxville, Tennessee, 37996, USA
| | - Lizbeth Hedstrom
- Department of Biology, Brandeis University, 415 South Street, Waltham, MA, 02454, USA.,Department of Chemistry, Brandeis University, 415 South Street, Waltham, MA, 02454, USA
| | - Jerry M Parks
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.,Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Joshua K Michener
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.,BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA.,Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
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16
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Abstract
Mercury (Hg) is a global environmental contaminant. Major anthropogenic sources of Hg emission include gold mining and the burning of fossil fuels. Once deposited in aquatic environments, Hg can undergo redox reactions, form complexes with ligands, and adsorb onto particles. It can also be methylated by microorganisms. Mercury, especially its methylated form methylmercury, can be taken up by organisms, where it bioaccumulates and biomagnifies in the food chain, leading to detrimental effects on ecosystem and human health. In support of the recently enforced Minamata Convention on Mercury, a legally binding international convention aimed at reducing the anthropogenic emission of-and human exposure to-Hg, its global biogeochemical cycle must be understood. Thus, a detailed understanding of the molecular-level interactions of Hg is crucial. The ongoing rapid development of hardware and methods has brought computational chemistry to a point that it can usefully inform environmental science. This is particularly true for Hg, which is difficult to handle experimentally due to its ultratrace concentrations in the environment and its toxicity. The current account provides a synopsis of the application of computational chemistry to filling several major knowledge gaps in environmental Hg chemistry that have not been adequately addressed experimentally. Environmental Hg chemistry requires defining the factors that determine the relative affinities of different ligands for Hg species, as they are critical for understanding its speciation, transformation and bioaccumulation in the environment. Formation constants and the nature of bonding have been determined computationally for environmentally relevant Hg(II) complexes such as chlorides, hydroxides, sulfides and selenides, in various physical phases. Quantum chemistry has been used to determine the driving forces behind the speciation of Hg with hydrochalcogenide and halide ligands. Of particular importance is the detailed characterization of solvation effects. Indeed, the aqueous phase reverses trends in affinities found computationally in the gas phase. Computation has also been used to investigate complexes of methylmercury with (seleno)amino acids, providing a molecular-level understanding of the toxicological antagonism between Hg and selenium (Se). Furthermore, evidence is emerging that ice surfaces play an important role in Hg transport and transformation in polar and alpine regions. Therefore, the diffusion of Hg and its ions through an idealized ice surface has been characterized. Microorganisms are major players in environmental mercury cycling. Some methylate inorganic Hg species, whereas others demethylate methylmercury. Quantum chemistry has been used to investigate catalytic mechanisms of enzymatic Hg methylation and demethylation. The complex interplay between the myriad chemical reactions and transport properties both in and outside microbial cells determines net biogeochemical cycling. Prospects for scaling up molecular work to obtain a mechanistic understanding of Hg cycling with comprehensive multiscale biogeochemical modeling are also discussed.
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Affiliation(s)
- Abu Asaduzzaman
- Department of Chemistry, University of Manitoba, Winnipeg, MB Canada, R3T 2N2
- School of Science, Engineering and Technology, Penn State Harrisburg, 777 West Harrisburg Pike, Middletown, Pennsylvania 17057, United States
| | - Demian Riccardi
- University of Tennessee/Oak Ridge National Laboratory Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831-6309, United States
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee Knoxville, Knoxville, Tennessee 37996, United States
| | - Akef T. Afaneh
- Department of Chemistry, University of Manitoba, Winnipeg, MB Canada, R3T 2N2
- Department of Chemistry, Faculty of Science, Al-Balqa Applied University, P.O. Box 19117,
postal code 19117, Al-Salt, Jordan
| | - Connor J. Cooper
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Jeremy C. Smith
- University of Tennessee/Oak Ridge National Laboratory Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831-6309, United States
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee Knoxville, Knoxville, Tennessee 37996, United States
| | - Feiyue Wang
- Centre for Earth Observation Science and Department of Environment and Geography, University of Manitoba, Winnipeg, MB Canada, R3T 2N2
| | - Jerry M. Parks
- University of Tennessee/Oak Ridge National Laboratory Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831-6309, United States
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Georg Schreckenbach
- Department of Chemistry, University of Manitoba, Winnipeg, MB Canada, R3T 2N2
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Cooper CJ, Krishnamoorthy G, Wolloscheck D, Walker JK, Rybenkov VV, Parks JM, Zgurskaya HI. Molecular Properties That Define the Activities of Antibiotics in Escherichia coli and Pseudomonas aeruginosa. ACS Infect Dis 2018; 4:1223-1234. [PMID: 29756762 DOI: 10.1021/acsinfecdis.8b00036] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [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: 12/18/2022]
Abstract
The permeability barrier of Gram-negative cell envelopes is the major obstacle in the discovery and development of new antibiotics. In Gram-negative bacteria, these difficulties are exacerbated by the synergistic interaction between two biochemically distinct phenomena, the low permeability of the outer membrane (OM) and active multidrug efflux. In this study, we used Pseudomonas aeruginosa and Escherichia coli strains with controllable permeability barriers, achieved through hyperporination of the OMs and varied efflux capacities, to evaluate the contributions of each of the barriers to protection from antibacterials. We analyzed antibacterial activities of β-lactams and fluoroquinolones, antibiotics that are optimized for targets in the periplasm and the cytoplasm, respectively, and performed a machine learning-based analysis to identify physicochemical descriptors that best classify their relative potencies. Our results show that the molecular properties selected by active efflux and the OM barriers are different for the two species. Antibiotic activity in P. aeruginosa was better classified by electrostatic and surface area properties, whereas topology, physical properties, and atom or bond counts best capture the behavior in E. coli. In several cases, descriptor values that correspond to active antibiotics also correspond to significant barrier effects, highlighting the synergy between the two barriers where optimizing for one barrier promotes strengthening of the other barrier. Thus, both barriers should be considered when optimizing antibiotics for favorable OM permeability, efflux evasion, or both.
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Affiliation(s)
- Connor J. Cooper
- Graduate School of Genome Science and Technology, University of Tennessee, F225 Walters Life Science, Knoxville, Tennessee 37996, United States
| | - Ganesh Krishnamoorthy
- Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - David Wolloscheck
- Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - John K. Walker
- Department of Pharmacological & Physiological Science, Saint Louis University School of Medicine, St. Louis, Missouri 63104, United States
| | - Valentin V. Rybenkov
- Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Jerry M. Parks
- Graduate School of Genome Science and Technology, University of Tennessee, F225 Walters Life Science, Knoxville, Tennessee 37996, United States
- Biosciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831-6309, United States
| | - Helen I. Zgurskaya
- Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
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Langan PS, Vandavasi VG, Cooper CJ, Weiss KL, Ginell SL, Parks JM, Coates L. Substrate Binding Induces Conformational Changes in a Class A β-lactamase That Prime It for Catalysis. ACS Catal 2018. [DOI: 10.1021/acscatal.7b04114] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Patricia S. Langan
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Venu Gopal Vandavasi
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Connor J. Cooper
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Kevin L. Weiss
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Stephan L. Ginell
- Structural Biology Center, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Jerry M. Parks
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Tennessee 37996, United States
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6309, United States
| | - Leighton Coates
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
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Rivard BR, Cooper CJ, Stubbs JM. The role of differing probe and target strand lengths in DNA microarrays investigated via Monte Carlo molecular simulation. Chem Phys Lett 2018. [DOI: 10.1016/j.cplett.2018.01.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Zhou J, Smith MD, Cooper CJ, Cheng X, Smith JC, Parks JM. Modeling of the Passive Permeation of Mercury and Methylmercury Complexes Through a Bacterial Cytoplasmic Membrane. Environ Sci Technol 2017; 51:10595-10604. [PMID: 28806072 DOI: 10.1021/acs.est.7b02204] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Cellular uptake and export are important steps in the biotransformation of mercury (Hg) by microorganisms. However, the mechanisms of transport across biological membranes remain unclear. Membrane-bound transporters are known to be relevant, but passive permeation may also be involved. Inorganic HgII and methylmercury ([CH3HgII]+) are commonly complexed with thiolate ligands. Here, we have performed extensive molecular dynamics simulations of the passive permeation of HgII and [CH3HgII]+ complexes with thiolate ligands through a model bacterial cytoplasmic membrane. We find that the differences in free energy between the individual complexes in bulk water and at their most favorable position within the membrane are ∼2 kcal mol-1. We provide a detailed description of the molecular interactions that drive the membrane crossing process. Favorable interactions with carbonyl and tail groups of phospholipids stabilize Hg-containing solutes in the tail-head interface region of the membrane. The calculated permeability coefficients for the neutral compounds CH3S-HgII-SCH3 and CH3HgII-SCH3 are on the order of 10-5 cm s-1. We conclude that small, nonionized Hg-containing species can permeate readily through cytoplasmic membranes.
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Affiliation(s)
- Jing Zhou
- Graduate School of Genome Science and Technology, University of Tennessee , Knoxville, Tennessee 37996, United States
- UT/ORNL Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory , 1 Bethel Valley Road, Oak Ridge, Tennessee 37831-6309, United States
| | - Micholas Dean Smith
- UT/ORNL Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory , 1 Bethel Valley Road, Oak Ridge, Tennessee 37831-6309, United States
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee , Knoxville, Tennessee 37996, United States
| | - Connor J Cooper
- Graduate School of Genome Science and Technology, University of Tennessee , Knoxville, Tennessee 37996, United States
- UT/ORNL Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory , 1 Bethel Valley Road, Oak Ridge, Tennessee 37831-6309, United States
| | - Xiaolin Cheng
- UT/ORNL Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory , 1 Bethel Valley Road, Oak Ridge, Tennessee 37831-6309, United States
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee , Knoxville, Tennessee 37996, United States
| | - Jeremy C Smith
- UT/ORNL Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory , 1 Bethel Valley Road, Oak Ridge, Tennessee 37831-6309, United States
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee , Knoxville, Tennessee 37996, United States
| | - Jerry M Parks
- Graduate School of Genome Science and Technology, University of Tennessee , Knoxville, Tennessee 37996, United States
- UT/ORNL Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory , 1 Bethel Valley Road, Oak Ridge, Tennessee 37831-6309, United States
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21
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Nakonieczna A, Cooper CJ, Gryko R. Bacteriophages and bacteriophage-derived endolysins as potential therapeutics to combat Gram-positive spore forming bacteria. J Appl Microbiol 2015; 119:620-31. [PMID: 26109320 DOI: 10.1111/jam.12881] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [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: 03/02/2015] [Revised: 05/28/2015] [Accepted: 06/11/2015] [Indexed: 01/21/2023]
Abstract
Since their discovery in 1915, bacteriophages have been routinely used within Eastern Europe to treat a variety of bacterial infections. Although initially ignored by the West due to the success of antibiotics, increasing levels and diversity of antibiotic resistance is driving a renaissance for bacteriophage-derived therapy, which is in part due to the highly specific nature of bacteriophages as well as their relative abundance. This review focuses on the bacteriophages and derived lysins of relevant Gram-positive spore formers within the Bacillus cereus group and Clostridium genus that could have applications within the medical, food and environmental sectors.
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Affiliation(s)
- A Nakonieczna
- Biological Threats Identification and Countermeasure Center of the Military Institute of Hygiene and Epidemiology, Pulawy, Poland
| | - C J Cooper
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - R Gryko
- Biological Threats Identification and Countermeasure Center of the Military Institute of Hygiene and Epidemiology, Pulawy, Poland
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Taleb M, Puffer AJ, Moza A, Elahinia M, Cooper CJ. Review of current technologies for thromboembolism management. Minerva Cardioangiol 2014; 62:343-357. [PMID: 25012101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Percutaneous thrombectomy is being widely used as a sole therapy or as an adjunct to other therapies for the management of thrombotic occlusions in arteries, veins and grafts. Various techniques used can be broadly classified under percutaneous aspiration thrombectomy, pull-back thrombectomy and trapping, recirculation mechanical thrombectomy, direct contact/non-recirculation thrombectomy and direct or indirect ultrasound thrombectomy. In the following article, we will provide a review of these techniques describing the commonly utilized devices and their characteristics.
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Affiliation(s)
- M Taleb
- Department of Medicine University of Toledo Medical Center Toledo, OH, USA -
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Shipp EM, Cooper SP, del Junco DJ, Bolin JN, Whitworth RE, Cooper CJ. Pesticide safety training among farmworker adolescents from Starr County, Texas. J Agric Saf Health 2007; 13:311-21. [PMID: 17892073 DOI: 10.13031/2013.23354] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [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: 11/11/2022]
Abstract
This study of adolescent farmworkers describes employer compliance with pesticide safety training, a requirement of the EPA-mandated Worker Protection Standard (WPS), and identifies variables associated with having received training within the prior five years. Data are from "A Study of Work Injuries in Farmworker Children, " a three-year cohort study of high school students living along the Texas-Mexico border in Starr County. Data were collected using a web-based, self-administered, confidential survey. Of 324 students who participated in field work between January 1 and September 30, 2003, 68 (21.0%) reported ever receiving pesticide safety training. Overall, the 61 (18.8%) students who reported training within the prior five years also reported that their most recent instruction covered at least three key WPS areas (i.e., entry into a recently treated field, pesticide-related injuries/illnesses, and emergency care for pesticide exposure). Based on a multiple logistic regression, students who were male (OR = 1.97), worked only outside of Texas (OR = 2.73), worked only for commercial growers/owners (OR = 4.35), worked only for contractors (OR = 3.18), worked corn crops (OR = 2.93), and worked potato crops (OR = 3.11) were more likely to report receipt of training within the prior five years. Results suggest that increased enforcement may be needed, especially in Texas, and special educational efforts may be needed to reach female farmworker youth.
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Affiliation(s)
- E M Shipp
- Department of Epidemiology and Biostatistics, Texas A&M Health Science Center School of Rural Public Health, College Station 77843-1266, USA.
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del Junco DJ, Cooper SP, Shipp EM, Cooper CJ. Injuries in South Texas Farmworker Adolescents. Am J Epidemiol 2006. [DOI: 10.1093/aje/163.suppl_11.s216-c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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25
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Hur SH, Kitamura K, Morino Y, Honda Y, Jones M, Korr KS, Reen B, Cooper CJ, Niess GS, Christie L, Corey W, Messenger J, Yock PG, Cummins F, Fitzgerald PJ. Efficacy of postdeployment balloon dilatation for current generation stents as assessed by intravascular ultrasound. Am J Cardiol 2001; 88:1114-9. [PMID: 11703954 DOI: 10.1016/s0002-9149(01)02044-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Adjunctive balloon dilatation strategy has been shown to improve optimal stent deployment. As improvements in current stent designs evolve, less adjunctive balloon dilatation may be needed. However, few data currently exist to support this practice. We evaluated 88 native coronary lesions treated with single stent implantation (Nir, Tristar or S670). Serial intravascular ultrasound was performed after successful stent deployment and again after adjunctive balloon dilatation. To investigate further the precise expansion characteristics of the stents, serial volumetric intravascular ultrasound analyses were performed in 40 patients with automated pullback. After adjunctive balloon dilatation, minimal stent area increased significantly, from 6.4 +/- 2.1 to 7.4 +/- 2.2 mm(2) (p <0.001). Volumetric analysis showed a corresponding increase in stent volume index (6.6 +/- 1.8 to 7.5 +/- 2.0 mm(3)/mm, p <0.001). In the analysis of cross sections at 0.5-mm axial intervals, the percentage of cross sections, where stent area was > or =80% of the average reference lumen area, increased from 51% to 78% (p <0.001). Similarly, the percentage of cross sections, where stent area was > or =90% of the average reference lumen area, increased from 29% to 56% (p <0.001) with postdilatation. Postdeployment high- pressure balloon dilatation improved minimal stent area and volumetric expansion throughout the stented segment.
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Affiliation(s)
- S H Hur
- Center for Research in Cardiovascular Interventions, Stanford University Medical Center, Stanford, California 94305-5637, USA
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Wu SS, Galani RJ, Bahro A, Moore JA, Burket MW, Cooper CJ. 8 french transradial coronary interventions: clinical outcome and late effects on the radial artery and hand function. J Invasive Cardiol 2000; 12:605-9. [PMID: 11103026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
BACKGROUND Limited information is available on the effects of 8 French (Fr) transradial procedures on radial patency. In addition, the effects of radial procedures and radial occlusion on hand function are unknown. METHODS Two groups were recruited: twenty-four patients who had undergone 26 transradial 8 Fr interventions and 16 patients who had undergone 16 transradial 6 Fr procedures. At 1 year, radial patency, hand strength and hand endurance were measured. RESULTS No major adverse cardiac events or vascular complications were noted in either group. Late radial occlusion was noted in 2/18 (11%) 8 Fr patients and 3/16 (19%) 6 Fr patients (p = ns). There were no differences in the 8 Fr group between the catheterized and uncatheterized radial arteries for diameter (3.2 +/- 1.1 mm versus 3.3 +/- 0.7 mm, respectively; p = NS) or volumetric flow (55 +/- 51 ml/minute versus 57 +/- 45 ml/minute, respectively; p = NS). No differences in hand strength or hand endurance were seen between the catheterized and uncatheterized arms in the 8 Fr group, between the 8 Fr and 6 Fr groups, or between occluded and non-occluded patients. CONCLUSION Transradial use of 8 Fr guiding catheters appears to be feasible and safe in highly selected patients, albeit associated with a low incidence of silent radial occlusion. Additionally, neither the use of 8 Fr sheaths nor the presence of radial artery occlusion appear to adversely affect hand strength or endurance.
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Affiliation(s)
- S S Wu
- Medical College of Ohio, Cardiology Division, 3000 Arlington Avenue, Toledo, OH, 43699-0008, USA
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Abstract
BACKGROUND & AIMS Previous data suggest that oral antigen induces interferon (IFN)-gamma production in intestinal T cells. However, oral tolerance is associated with decreased production of IFN-gamma by T cells after antigen sensitization. The aim of this study was to examine the role of IFN-gamma in oral tolerance. METHODS Oral tolerance was examined in BALB/c mice after the adoptive transfer of T cells from chicken ovalbumin (OVA(323-339))-specific, DO11.10 x RAG-1(-/-) T-cell receptor transgenic mice. RESULTS OVA feeding induced systemic tolerance of delayed-type hypersensitivity (DTH) and antibody responses. OVA feeding up-regulated IFN-gamma production by transgenic T cells in Peyer's patch and mesenteric lymph node but not splenic tissues. Treatment of OVA-fed mice with neutralizing monoclonal antibody to IFN-gamma prevented tolerance of DTH responses. Analysis of transgenic T-cell numbers in DTH sites by immunohistochemical staining suggested that induction of IFN-gamma by oral antigen decreased accumulation of transgenic T cells in cutaneous sites of antigen injection. IFN-gamma-deficient or wild-type DO11.10 and BALB/c mice were used to show that IFN-gamma production by donor transgenic T cells was critical for oral tolerance. CONCLUSIONS These data suggest that the induction of IFN-gamma by oral antigen contributes to systemic tolerance by decreasing migration of T cells to peripheral sites of inflammation.
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MESH Headings
- Administration, Oral
- Adoptive Transfer
- Animals
- Antibodies, Monoclonal/immunology
- Antibodies, Monoclonal/pharmacology
- Cell Movement/physiology
- Chickens
- Genes, RAG-1/genetics
- Hypersensitivity, Delayed/immunology
- Hypersensitivity, Delayed/pathology
- Immune Tolerance/drug effects
- Immune Tolerance/physiology
- Inflammation/physiopathology
- Interferon-gamma/biosynthesis
- Interferon-gamma/immunology
- Interferon-gamma/physiology
- Leukocyte Count
- Mice
- Mice, Inbred BALB C
- Mice, Transgenic/genetics
- Mouth/immunology
- Ovalbumin/pharmacology
- Receptors, Antigen, T-Cell/genetics
- T-Lymphocytes/immunology
- T-Lymphocytes/pathology
- T-Lymphocytes/physiology
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Affiliation(s)
- H O Lee
- Division of Gastroenterology and Hepatology, Department of Medicine, Northwestern University Medical School, Chicago, Illinois, USA
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Burket MW, Cooper CJ, Kennedy DJ, Brewster PS, Ansel GM, Moore JA, Venkatesan J, Henrich WL. Renal artery angioplasty and stent placement: predictors of a favorable outcome. Am Heart J 2000; 139:64-71. [PMID: 10618564 DOI: 10.1016/s0002-8703(00)90310-7] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Renal artery stenosis is a common disorder and is an established cause of hypertension and renal insufficiency. Although treatment with renal artery stents has been shown to improve blood pressure and renal function for some patients, the patient population most likely to benefit is unknown. The current study was designed to determine which factors are predictive of improved blood pressure and renal function when patients with renal artery stenosis are treated with renal artery angioplasty and stent placement. METHODS In a prospective evaluation 127 consecutively enrolled patients with renal artery stenosis in 171 vessels were treated with angioplasty and intravascular stents. Blood pressure and serum creatinine concentration were measured before stent placement and during the follow-up period. RESULTS The mean length of the follow-up period was 15 +/- 14 months. Mean systolic blood pressure improved among patients with hypertension (from 177 +/- 26 mm Hg before stent placement to 151 +/- 24 mm Hg 6 months after stent placement (P <.001). The greatest improvement occurred among those with the highest baseline systolic blood pressure. This beneficial effect on blood pressure was sustained for 3 years. Sex, age, diastolic blood pressure, number of vessels into which stents were placed, serum creatinine concentration, presence of bilateral disease, race, and severity of stenosis were not predictive of improved blood pressure. Mean creatinine concentration was not significantly changed for the group as a whole. A significant decrease in serum creatinine concentration occurred among 43% of patients with baseline renal insufficiency. None of the examined variables was predictive of improvement. CONCLUSIONS Renal artery angioplasty and stent placement produced a significantly greater reduction in systolic blood pressure among patients with the highest baseline systolic blood pressure. Other examined variables were not predictive of a significant improvement in blood pressure. No examined variable was predictive of improved renal function. We concluded that management of renal artery stenosis with renal artery angioplasty and stent placement is most likely to result in significant improvement in systolic blood pressure among patients with the highest baseline systolic blood pressure.
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Affiliation(s)
- M W Burket
- Divisions of Cardiology and Nephrology, Department of Medicine, Medical College of Ohio, USA.
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Hurst SD, Cooper CJ, Sitterding SM, Choi JH, Jump RL, Levine AD, Barrett TA. The differentiated state of intestinal lamina propria CD4+ T cells results in altered cytokine production, activation threshold, and costimulatory requirements. J Immunol 1999; 163:5937-45. [PMID: 10570280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Intestinal lamina propria (LP) CD4+ T cells are memory-like effector cells that proliferate at relatively low levels and require high levels of TCR signaling and costimulation for full activation in vitro. To study LP CD4+ T cell functional potential we used DO11.10 TCR transgenic (Tg) mice specific for the class II MHC-restricted OVA323-339 peptide and nontransgenic BALB/c mice. Activation of LP Tg+ T cells with Ag using mucosal explants induced high levels of IL-2, IL-4, and IFN-gamma. Culturing isolated LP cells with IL-12 enhanced IFN-gamma production and down-regulated IL-4 and IL-2, whereas addition of IL-4 maintained IL-4 production without inhibiting IFN-gamma production. Systemic administration of relatively high dose (HD; 100 nM) OVA323-339 peptide induced similar levels of bromodeoxyuridine (BrdU) incorporation by LP and splenic Tg+ T cells in vivo, whereas low dose (LD; 4.5 nM) peptide injections induced 4-fold greater levels of BrdU incorporation for LP compared with splenic Tg+ T cells. Coadministration of CTLA-4Ig reduced BrdU incorporation for splenic cells by 70% with HD and LD stimulation, but had little effect on LP responses to HD stimulation. Results of in vivo studies were confirmed in nontransgenic BALB/c mice using HD (200 microg) and LD (10 microg) anti-CD3 mAb+/- CTLA-4Ig. These results suggest that LP T cells are differentiated effector cells that respond at high levels when activated with relatively low levels of Ag- and B7-mediated costimulation in vivo. The reduced activation threshold of LP T cells may facilitate responses to low levels of Ag derived from mucosal pathogens.
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Affiliation(s)
- S D Hurst
- Veterans Administration Lakeside Medical Research Center and Department of Medicine, Section of Gastroenterology, Northwestern University Medical School, Chicago, IL 60611, USA
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Cooper CJ, El-Shiekh RA, Cohen DJ, Blaesing L, Burket MW, Basu A, Moore JA. Effect of transradial access on quality of life and cost of cardiac catheterization: A randomized comparison. Am Heart J 1999; 138:430-6. [PMID: 10467191 DOI: 10.1016/s0002-8703(99)70143-2] [Citation(s) in RCA: 420] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND Transradial access is a recently developed alternative for diagnostic cardiac catheterization. Its effects on quality of life after the procedure, patient preference, and cost are unknown. METHODS AND RESULTS We performed a randomized single-center trial in which 99 patients underwent transfemoral and 101 underwent transradial diagnostic cardiac catheterization. Quality of life was measured with the SF-36 and visual analog scales at baseline, 1 day, and 1 week. Patients were examined at 1 day and at 1 week after for complications. Costs were measured prospectively. One patient in the femoral group and 2 in the radial group crossed over to the alternative access site. There were no major access site complications. One patient in the transfemoral group had a minor stroke. Transradial catheterization significantly reduced median length of stay (3.6 vs 10.4 hours, P <.0001). Over the first day after the procedure, measures of bodily pain, back pain, and walking ability favored the transradial group (P <.05 for all comparisons). Over the week after the procedure, changes in role limitations caused by physical health, bodily pain, and back pain favored the transradial group (P <.05 for all comparisons). There was a strong patient preference for transradial catheterization as well (P <. 0001). Transradial catheterization led to significant reductions in bed, pharmacy, and total hospital costs ($2010 vs $2299, P <.0001). CONCLUSIONS Among patients undergoing diagnostic cardiac catheterization, transradial access leads to improved quality of life after the procedure, is strongly preferred by patients, and reduces hospital costs.
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Affiliation(s)
- C J Cooper
- Medical College of Ohio, Cardiology Division, Toledo, Ohio 43699-0008, USA.
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Cooper CJ, Jevnikar FW, Walsh T, Dickinson J, Mouhaffel A, Selwyn AP. The influence of basal nitric oxide activity on pulmonary vascular resistance in patients with congestive heart failure. Am J Cardiol 1998; 82:609-14. [PMID: 9732889 DOI: 10.1016/s0002-9149(98)00400-7] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Increased pulmonary resistance may reduce survival and treatment options in patients with congestive heart failure. Nitric oxide (NO) is a determinant of normal pulmonary resistance vessel tone. We tested the hypothesis that loss of NO function contributes to increased pulmonary vascular resistance index (PVRI) in congestive heart failure. Pulmonary arterial resistance vessel function was studied in 25 conscious adults. Three groups were studied: 8 controls, 9 patients with congestive heart failure and normal PVRI, and 8 patients with congestive heart failure and raised PVRI. Segmental arterial flow was determined with a Doppler wire and quantitative angiography. NG-monomethyl-L-arginine (L-NMMA) was used to inhibit NO, whereas phenylephrine was used as an endothelium-independent control. The response to inhibition of NO with L-NMMA was less in patients with congestive heart failure and elevated PVRI than in patients with congestive heart failure and normal PVRI (p <0.05). The difference in response between the congestive heart failure groups was specific to NO-dependent regulation because the response to the endothelium-independent constrictor phenylephrine was not different (p = 0.92). There was no difference in response to L-NMMA between controls and patients with congestive heart failure and normal PVRI. The response to L-NMMA correlated to PVRI. In adults with congestive heart failure, NO appears to play an important role in maintaining normal pulmonary resistance.
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Affiliation(s)
- C J Cooper
- Department of Medicine, Medical College of Ohio, Toledo 43699-0008, USA
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Colyer WR, Moore JA, Burket MW, Cooper CJ. Intraaortic balloon pump insertion after percutaneous revascularization in patients with severe peripheral vascular disease. Cathet Cardiovasc Diagn 1997; 42:1-6. [PMID: 9286527 DOI: 10.1002/(sici)1097-0304(199709)42:1<1::aid-ccd1>3.0.co;2-8] [Citation(s) in RCA: 10] [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] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Severe aortoiliac peripheral vascular disease (PVD) is considered a contraindication for the placement of an intraaortic balloon pump (IABP) because of a high risk of limb ischemia. Recent advances in percutaneous transluminal angioplasty (PTA) and stenting have altered the treatment of iliac stenoses such that the results of PTA with stenting compare favorably with surgery. We reviewed our experience with placement of IABP between July 1994 and February 1996. Of 64 patients receiving IABP, 17 had known or suspected peripheral vascular disease. Severe iliac or distal aortic stenoses were present in 9. These 9 patients underwent PTA with or without stenting prior to 10 IABP insertions. Limb ischemia occurred in 10% of PVD patients treated with percutaneous revascularization, compared to 11% in patients without PVD. No patient had a serious vascular complication or required vascular surgery. We conclude that percutaneous revascularization in patients with severe aortoiliac PVD, for whom this IABP insertion had previously been considered contraindicated, results in a low rate of limb ischemia.
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Affiliation(s)
- W R Colyer
- Cardiology Division, Medical College of Ohio, Toledo 43699-0008, USA
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Abstract
The event-related brain potential (ERP) has been investigated extensively inan effort to understand the neurophysiological bases of intelligence. Measures derived from the ERP have been used as indices of intelligence, particularly the string measure of the complexity of the ERP. However, the string measure has been criticised for being non-specific and for being dependent on ERP amplitude. These criticisms were tested by investigating relationships between ERP string measure, ERP amplitude measures, and the ERP power spectrum. It was found that the string measure was non-specific in that it indexes both low and high frequency event-related activity; the string measure is also dependent on ERP amplitude. The string measure is therefore not a valid measure of the ERP. It was concluded that the string measure should be abandoned; human intelligence cannot map in a simple way onto gross measures of scalp-recorded electrocortical activity.
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Affiliation(s)
- N R Burns
- Department of Psychology, University of Adelaide, South Australia, Australia.
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Hardy RJ, Palmer EA, Schaffer DB, Phelps DL, Davis BR, Cooper CJ. Outcome-based management of retinopathy of prematurity. Multicenter Trial of Cryotherapy for Retinopathy of prematurity Cooperative Group. J AAPOS 1997; 1:46-54. [PMID: 10530985 DOI: 10.1016/s1091-8531(97)90023-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
PURPOSE A system is presented for sequentially computing the risk of progression of retinopathy of prematurity (ROP) for infants born weighing not more than 1250 gm. A personal computer program is used to monitor infants' risk of threshold ROP from first appearance of ROP, and the progression in severity is tracked with multiple logistic risk models developed from data in the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity. METHODS After entry of the infant's birth weight, gestational age, ethnicity, birth in the current hospital or elsewhere, single or multiple birth, and maturity zone of retinal vessels, risk of progression to threshold severity is calculated. New estimates of risk are computed at onset of ROP and prethreshold ROP (any zone I ROP, zone II stage 2+ or 3) according to the extent of retinal vascularization when ROP first appears, how rapidly ROP progresses, and how severe it is. When threshold ROP (8 total or 5 contiguous clock hours of stage 3+ in zone I or II) is reached,the system provides separate estimates of risk that the eye will have an unfavorable 3-month outcome if treated or not. RESULTS Estimates of risk of progression to threshold disease among the 4099 patients in the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity natural history study varied from less than 1% to more than 70%. For eyes with threshold disease, the risk of an unfavorable outcome at 3 months without treatment varied from less than 10% to more than 90%. CONCLUSION This method of tracking identifies infants at high risk for severe ROP and poor structural outcome. It provides information about prognosis with a specificity heretofore impossible.
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Affiliation(s)
- R J Hardy
- University of Texas Health Science Center at Houston, School of Public Health 77030, USA
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Abstract
Transradial coronary stenting has been associated with a low frequency of vascular complications and shortened hospital length of stay, but few reports of safety and feasibility are available. To determine the safety and efficacy of transradial coronary stenting, our initial experience in 38 patients was reviewed. Palmaz-Schatz stents hand-mounted on Predator (Cordis Corp., Miami Lakes, FL) balloons were delivered through 6 Fr guide catheters. In 1 of 38 patients (3%) radial access could not be achieved. Fifty-five stents were implanted in 44 lesions (3 total occlusion, 18 type A, 19 type B, 9 type C, National Heart Lung Blood Institute Classification). Access time was 7.7 +/- 4.6 min. Procedural success was achieved in 36 patients (97%). In one patient, a stent could not be delivered to a distal circumflex lesion due to marked proximal tortuosity and calcification. Poststenting residual stenosis was 0 +/0 10%. No access-related complications occurred. One patient had stent thrombosis and required repeat angioplasty and stenting. We conclude that transradial coronary stenting is both feasible and safe with a low risk of access complications and with excellent procedural results.
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Affiliation(s)
- R A el-Shiekh
- Department of Medicine, Medical College of Ohio, Toledo 43699, USA
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Cooper CJ, Noakes TD, Dunne T, Lambert MI, Rochford K. A high prevalence of abnormal personality traits in chronic users of anabolic-androgenic steroids. Br J Sports Med 1996; 30:246-50. [PMID: 8889121 PMCID: PMC1332342 DOI: 10.1136/bjsm.30.3.246] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [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: 02/02/2023]
Abstract
OBJECTIVE (1) To assess the personality profiles of the anabolic androgenic steroid users (AAS) and (2) to determine whether valid premorbid personality traits could be obtained from cross sectional assessment using multisource data. METHODS The first author became a participant-observer in a group of body builders. An experimental group of body builders who had been using AAS for no more than 18 months (n = 12) was identified. A group of control subjects, each of whom claimed that he did not, and never had, used AAS (n = 12) was also recruited during this period. Key informants played a crucial role in recruiting subjects representative of the AAS and body building communities. An interview schedule based on the Diagnostic and statistical manual of mental disorders (DSM3-R) personality disorder criteria was conducted with each subject. Additional data were obtained from an AAS using informant and significant others including family and friends. RESULTS The user group was significantly heavier than the control group and showed abnormal personality traits, in contrast to the control group. Personality traits of AAS users before the onset of AAS use, assessed retrospectively, were not different from personality traits of control subjects. There were significant differences between the before and after personality traits in AAS user group. CONCLUSIONS The results suggest (1) that AAS use is associated with significant disturbances in personality profile, and (2) that these personality disturbances are possibly the direct result of AAS use.
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Affiliation(s)
- C J Cooper
- Faculty of Science, University of Cape Town, South Africa
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Townsend CG, Edwards NH, Zetie KP, Cooper CJ, Rink J, Foot CJ. High-density trapping of cesium atoms in a dark magneto-optical trap. Phys Rev A 1996; 53:1702-1714. [PMID: 9913063 DOI: 10.1103/physreva.53.1702] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Cooper CJ, Landzberg MJ, Anderson TJ, Charbonneau F, Creager MA, Ganz P, Selwyn AP. Role of nitric oxide in the local regulation of pulmonary vascular resistance in humans. Circulation 1996; 93:266-71. [PMID: 8548898 DOI: 10.1161/01.cir.93.2.266] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Endothelium-derived nitric oxide (NO) may be an important mediator of vascular resistance in the pulmonary circulation. We tested the hypotheses that in conscious adults the endothelium, through NO production, is important in maintaining basal pulmonary vascular resistance and that it can increase NO production further in response to receptor-mediated stimulation, leading to further vasodilation. METHODS AND RESULTS Pulmonary arterial resistance vessel function was studied within the distribution of a segmental lower lobe pulmonary artery in eight conscious adults 37 to 76 years old who were undergoing cardiac catheterization. Segmental blood flow was determined with use of a Doppler-tip guide wire and quantitative angiography. Drugs were administered locally within the segmental artery through an infusion catheter. NG-Monomethyl-L-arginine (L-NMMA) was used as a specific inhibitor of NO production, whereas acetylcholine (ACh) was used to test receptor-mediated vasodilation. To demonstrate that vasodilation to ACh was NO dependent, ACh response was tested alone, in the presence of L-NMMA, and in the presence of a control constrictor phenylephrine. Basal pulmonary vascular resistance was NO dependent because L-NMMA infusion resulted in a dose-dependent decrease in local flow velocity (P < .005), with flow decreasing 33% at the highest dose of L-NMMA. ACh infusion resulted in a dose-dependent increase in flow velocity (P = .001). The ACh response was at least in part NO dependent because it was diminished by the presence of L-NMMA (P < .05). The effect of L-NMMA on the ACh response was not due to nonspecific preconstriction because L-NMMA diminished the ACh response significantly more than did the endothelium-independent constrictor phenylephrine (P < .05) despite comparable preconstriction. CONCLUSIONS In healthy conscious adults, (1) normal basal pulmonary resistance is maintained in part by continuous local production of NO and (2) the local NO production is responsive to receptor-mediated stimulation, leading to further vasodilation, and can be tested with ACh.
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Affiliation(s)
- C J Cooper
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
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Townsend CG, Edwards NH, Cooper CJ, Zetie KP, Foot CJ, Steane AM, Szriftgiser P, Perrin H, Dalibard J. Phase-space density in the magneto-optical trap. Phys Rev A 1995; 52:1423-1440. [PMID: 9912381 DOI: 10.1103/physreva.52.1423] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Warshauer DM, Molina PL, Hamman SM, Koehler RE, Paulson EK, Bechtold RE, Perlmutter ML, Hiken JN, Francis IR, Cooper CJ. Nodular sarcoidosis of the liver and spleen: analysis of 32 cases. Radiology 1995; 195:757-62. [PMID: 7754007 DOI: 10.1148/radiology.195.3.7754007] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.4] [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: 01/27/2023]
Abstract
PURPOSE To describe the computed tomographic (CT) appearance of nodular hepatosplenic sarcoidosis and its association with stage with chest radiography and clinical status. MATERIALS AND METHODS Thirty-two patients (21 women, 11 men; aged 25-68 years) with nodular hepatosplenic sarcoidosis were evaluated. CT findings were described along with chest radiographic stage, clinical status, and level of angiotensin-converting enzyme (ACE). RESULTS Nodules were small, multiple, and of low attenuation. Organomegaly was common. Abdominal adenopathy was present in 76% of the patients. Chest radiographs were normal in 25%; 61% had stage 1 or 2 radiographs. Abdominal or systemic symptoms were present in 66%. ACE level was elevated in 10 (91%) of 11 patients tested. No change in chest radiographic stage was noted in 74% of patients with follow-up radiographs. CONCLUSION Nodular hepatosplenic sarcoidosis is associated with organomegaly, adenopathy, and symptoms. Nodules were not associated with advanced lung disease and did not herald a change in chest radiographic stage. An elevated ACE level may be helpful in diagnosis.
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Affiliation(s)
- D M Warshauer
- Department of Radiology, University of North Carolina School of Medicine, Chapel Hill 27599-7510, USA
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Abstract
Helical (spiral) computed tomography (CT) is having a dramatic impact on body imaging. Unlike conventional CT, helical CT provides continued volumetric acquisition as the patient moves through the gantry. Advantages of helical CT include dramatically shortened examination times, improved visibility of vascular structures, better enhancement of parenchymal organs, the capability for retrospective imaging and three-dimensional (3D) vascular studies, and potential reduction in use of contrast material. However, helical CT requires one to be more cognizant of the relationship between contrast material administration and scanning, since the optimal temporal window for detection of disease can be missed. Factors unique to helical technology can produce artifacts, which one must be aware of when interpreting helically generated scans. Many of these artifacts relate to accentuation of vascular or parenchymal enhancement. Others occur during production of high-quality 3D images. Additional artifacts are sure to be identified with increased experience with helical CT.
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Affiliation(s)
- P M Silverman
- Department of Radiology, Georgetown University Medical Center, Washington, DC 20007
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Cooper CJ, Noakes TD. Psychiatric disturbances in users of anabolic steroids. S Afr Med J 1994; 84:509-12. [PMID: 7825091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
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Abstract
Endomyocardial biopsy is conventionally performed by accessing the right internal jugular vein. The alternative approach is via the femoral veins. We describe the safe and effective use of the left internal jugular vein with a standard Caves-Schulz bioptome.
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Affiliation(s)
- P J Hauptman
- Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02115
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Zeman RK, Zeiberg AS, Davros WJ, Ascher SM, Cooper CJ, Weltman DI, Patt R, Garra BS, Griego DL, Silverman PM. Routine helical CT of the abdomen: image quality considerations. Radiology 1993; 189:395-400. [PMID: 8210365 DOI: 10.1148/radiology.189.2.8210365] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [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: 01/29/2023]
Abstract
PURPOSE Both helical and nonhelical abdominal computed tomographic (CT) scans were obtained to compare image quality, study the effect of patient size and collimation, and compare the frequency of visualization of normal abdominal structures. MATERIALS AND METHODS The study group consisted of 60 consecutive patients with clinically suspected metastatic malignancy. RESULTS Both helical and nonhelical image quality was excellent, with equal mean image quality scores of 4.1 on a 5-point scale. In patients weighing more than 175 lb (79 kg), both helical and nonhelical image quality degraded equally when 5-mm collimation was used; 10-mm collimation resulted in excellent image quality, regardless of patient size. Small in-plane structures (eg, renal arteries, renal veins, pancreatic duct) were seen best on helical scans. With the addition of retrospectively reconstructed overlapping images, improvement in visualization of these structures was statistically significant. CONCLUSION Helical CT scanning should be the preferred means of acquiring routine abdominal CT images.
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Affiliation(s)
- R K Zeman
- Department of Radiology, Georgetown University Medical Center, Washington, DC 20007
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Abstract
Occupational and industrial hazards are unevenly distributed in the workplace. National estimates for selected health indices of persons aged 17 years and over in the civilian noninstitutionalized population are presented for categories of longest held occupation and industry of employment. These estimates were based on data collected by the National Center for Health Statistics (NCHS) in the 1980 National Health Interview Survey (NHIS) and the Occupational Supplement, the first survey to collect data on longest held, in addition to current, occupation and industry of employment. Data on length of longest held job, limitation of activity, disability days, incidence of acute conditions, persons injured, hospitalizations, and utilization of medical and dental services are presented.
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Affiliation(s)
- S P Cooper
- Health Law and Policy Institute, University of Houston, Texas
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49
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Abstract
Since its clinical introduction in the mid 1970s, techniques for CT have undergone many changes that have dramatically altered how CT scans are obtained. Helical (spiral) CT allows for faster acquisition of truly volumetric CT data than is possible with conventional scanners. Routine helical CT of the abdomen is now possible because of three major technical refinements: the development of the slip-ring gantry, improved detector efficiency, and greater tube cooling capability. This article reviews the technical principles that govern helical CT, the potential advantages and disadvantages of this technique, and initial clinical experience with helical CT of the abdomen.
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Affiliation(s)
- R K Zeman
- Department of Radiology, Georgetown University Medical Center, Washington, DC 20007-2197
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50
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Zeman RK, Davros WJ, Goldberg JA, Fanney D, Forer LE, Garra BS, Hayes WS, Horii SC, Cooper CJ, Silverman PM. Gallstone lithotripsy: results when number of stones is excluded as a criterion for treatment. AJR Am J Roentgenol 1991; 157:747-52. [PMID: 1892029 DOI: 10.2214/ajr.157.4.1892029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [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: 12/29/2022]
Abstract
The Siemens Lithostar Plus protocol (Siemens Medical Systems, Iselin, NJ) allows investigators to perform gallstone lithotripsy on patients regardless of the number of stones they have, provided the stones occupy less than 50% of the gallbladder lumen. The purpose of this study was to determine the interrelationships between stone burden, fragmentation response, and stone-free rates when treatment is not limited to three stones or fewer. Of 200 patients initially examined, 80 (40%) underwent lithotripsy. The mean number of treatments per patient was 2.1, and the mean number of shock waves per patient was 7386. In 60 patients in whom 6-month follow-up was available, the overall stone-free rate, based on actual results, was 32% (19/60). The stone-free rates for solitary stones, two or three stones, and four or more stones were 50%, 12%, and 26%, respectively. Regardless of number of stones, patients who ultimately became stone free had significantly smaller mean fragment size (0.25 cm) 2 weeks after lithotripsy than did those who did not become stone free (0.51 cm). Retrospective volume analysis showed that seven (47%) of 15 patients with multiple stones occupying less than 2000 mm3 were stone free; none became stone free when this volume was exceeded. Lithotripsy remains a practical option for patients with solitary stones. Comparable stone-free rates to those achieved for solitary stones can be obtained in patients with multiple stones, regardless of their number, provided treatment is aggressive and the stone aggregate is less than 2000 mm3.
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Affiliation(s)
- R K Zeman
- Department of Radiology, Georgetown University Medical Center, Washington, DC 20007
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