1
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Schaller MA, Sharma Y, Dupee Z, Nguyen D, Urueña J, Smolchek R, Loeb JC, Machuca TN, Lednicky JA, Odde DJ, Campbell RF, Sawyer WG, Mehrad B. Ex vivo SARS-CoV-2 infection of human lung reveals heterogeneous host defense and therapeutic responses. JCI Insight 2021; 6:e148003. [PMID: 34357881 PMCID: PMC8492301 DOI: 10.1172/jci.insight.148003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [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: 01/22/2021] [Accepted: 08/04/2021] [Indexed: 12/15/2022] Open
Abstract
Cell lines are the mainstay in understanding the biology of COVID-19 infection but do not recapitulate many of the complexities of human infection. The use of human lung tissue is one solution for the study of such novel respiratory pathogens. We hypothesized that a cryopreserved bank of human lung tissue would allow for the ex vivo study of the interindividual heterogeneity of host response to SARS-CoV-2, thus providing a bridge between studies with cell lines and studies in animal models. We generated a cryobank of tissues from 21 donors, many of whom had clinical risk factors for severe COVID-19. Cryopreserved tissues preserved 90% cell viability and contained heterogenous populations of metabolically active epithelial, endothelial, and immune cell subsets of the human lung. Samples were readily infected with HCoV-OC43 and SARS-CoV-2 and demonstrated comparable susceptibility to infection. In contrast, we observed a marked donor-dependent heterogeneity in the expression of IL6, CXCL8, and IFNB1 in response to SARS-CoV-2. Treatment of tissues with dexamethasone and the experimental drug N-hydroxycytidine suppressed viral growth in all samples, whereas chloroquine and remdesivir had no detectable effect. Metformin and sirolimus, molecules with predicted but unproven antiviral activity, each suppressed viral replication in tissues from a subset of donors. In summary, we developed a system for the ex vivo study of human SARS-CoV-2 infection using primary human lung tissue from a library of donor tissues. This model may be useful for drug screening and for understanding basic mechanisms of COVID-19 pathogenesis.
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Affiliation(s)
- Matthew A. Schaller
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, College of Medicine
| | - Yamini Sharma
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, College of Medicine
| | - Zadia Dupee
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, College of Medicine
| | - Duy Nguyen
- Department of Mechanical and Aerospace Engineering, Herbert Wertheim College of Engineering
| | - Juan Urueña
- Department of Mechanical and Aerospace Engineering, Herbert Wertheim College of Engineering
| | - Ryan Smolchek
- Department of Mechanical and Aerospace Engineering, Herbert Wertheim College of Engineering
| | - Julia C. Loeb
- Department of Environmental and Global Health, College of Public Health and Health Professions, and Emerging Pathogens Institute; and
| | - Tiago N. Machuca
- Division of Cardiothoracic Surgery, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - John A. Lednicky
- Department of Environmental and Global Health, College of Public Health and Health Professions, and Emerging Pathogens Institute; and
| | - David J. Odde
- Department of Biomedical Engineering, College of Science and Engineering, University of Minnesota, Minneapolis, Minnesota, USA
| | - Robert F. Campbell
- Department of Drug Development, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - W. Gregory Sawyer
- Department of Mechanical and Aerospace Engineering, Herbert Wertheim College of Engineering
| | - Borna Mehrad
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, College of Medicine
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2
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Buskes M, Clements M, Bachovchin KA, Jalani HB, Leonard A, Bag S, Klug DM, Singh B, Campbell RF, Sciotti RJ, El-Sakkary N, Caffrey CR, Pollastri MP, Ferrins L. Structure-Bioactivity Relationships of Lapatinib Derived Analogs against Schistosoma mansoni. ACS Med Chem Lett 2020; 11:258-265. [PMID: 32184954 PMCID: PMC7073886 DOI: 10.1021/acsmedchemlett.9b00455] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 01/10/2020] [Indexed: 11/30/2022] Open
Abstract
We recently reported a series of compounds for a solubility-driven optimization campaign of antitrypanosomal compounds. Extending a parasite-hopping approach to the series, a subset of compounds from this library has been cross-screened for activity against the metazoan flatworm parasite, Schistosoma mansoni. This study reports the identification and preliminary development of several potently bioactive compounds against adult schistosomes, one or more of which represent promising leads for further assessment and optimization.
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Affiliation(s)
- Melissa
J. Buskes
- Department
of Chemistry and Chemical Biology, Northeastern
University, Boston, Massachusetts 02115, United States
| | - Monica Clements
- Department
of Chemistry and Chemical Biology, Northeastern
University, Boston, Massachusetts 02115, United States
| | - Kelly A. Bachovchin
- Department
of Chemistry and Chemical Biology, Northeastern
University, Boston, Massachusetts 02115, United States
| | - Hitesh B. Jalani
- Department
of Chemistry and Chemical Biology, Northeastern
University, Boston, Massachusetts 02115, United States
| | - Allison Leonard
- Department
of Chemistry and Chemical Biology, Northeastern
University, Boston, Massachusetts 02115, United States
| | - Seema Bag
- Department
of Chemistry and Chemical Biology, Northeastern
University, Boston, Massachusetts 02115, United States
| | - Dana M. Klug
- Department
of Chemistry and Chemical Biology, Northeastern
University, Boston, Massachusetts 02115, United States
| | - Baljinder Singh
- Department
of Chemistry and Chemical Biology, Northeastern
University, Boston, Massachusetts 02115, United States
| | - Robert F. Campbell
- Experimental
Therapeutics, Walter Reed Army Institute
of Research, 2460 Linden Lane, Silver Spring, Maryland 20910, United
States
| | - Richard J. Sciotti
- Experimental
Therapeutics, Walter Reed Army Institute
of Research, 2460 Linden Lane, Silver Spring, Maryland 20910, United
States
| | - Nelly El-Sakkary
- Center
for Discovery and Innovation in Parasitic Diseases, Skaggs School
of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093, United States
| | - Conor R. Caffrey
- Center
for Discovery and Innovation in Parasitic Diseases, Skaggs School
of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093, United States
| | - Michael P. Pollastri
- Department
of Chemistry and Chemical Biology, Northeastern
University, Boston, Massachusetts 02115, United States
| | - Lori Ferrins
- Department
of Chemistry and Chemical Biology, Northeastern
University, Boston, Massachusetts 02115, United States
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3
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Singh B, Bernatchez JA, McCall LI, Calvet CM, Ackermann J, Souza JM, Thomas D, Silva EM, Bachovchin KA, Klug DM, Jalani HB, Bag S, Buskes MJ, Leed SE, Roncal NE, Penn EC, Erath J, Rodriguez A, Sciotti RJ, Campbell RF, McKerrow J, Siqueira-Neto JL, Ferrins L, Pollastri MP. Scaffold and Parasite Hopping: Discovery of New Protozoal Proliferation Inhibitors. ACS Med Chem Lett 2020; 11:249-257. [PMID: 32184953 DOI: 10.1021/acsmedchemlett.9b00453] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 01/10/2020] [Indexed: 11/29/2022] Open
Abstract
Utilizing a target repurposing and parasite-hopping approach, we tested a previously reported library of compounds that were active against Trypanosoma brucei, plus 31 new compounds, against a variety of protozoan parasites including Trypanosoma cruzi, Leishmania major, Leishmania donovani, and Plasmodium falciparum. This led to the discovery of several compounds with submicromolar activities and improved physicochemical properties that are early leads toward the development of chemotherapeutic agents against kinetoplastid diseases and malaria.
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Affiliation(s)
- Baljinder Singh
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States
| | - Jean A. Bernatchez
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093, United States
| | - Laura-Isobel McCall
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093, United States
| | - Claudia M. Calvet
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093, United States
| | - Jasmin Ackermann
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093, United States
| | - Julia M. Souza
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093, United States
| | - Diane Thomas
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093, United States
| | - Everton M. Silva
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093, United States
| | - Kelly A. Bachovchin
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States
| | - Dana M. Klug
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States
| | - Hitesh B. Jalani
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States
| | - Seema Bag
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States
| | - Melissa J. Buskes
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States
| | - Susan E. Leed
- Experimental Therapeutics, Walter Reed Army Institute of Research, 2460 Linden Lane, Silver Spring, Maryland 20910, United States
| | - Norma E. Roncal
- Experimental Therapeutics, Walter Reed Army Institute of Research, 2460 Linden Lane, Silver Spring, Maryland 20910, United States
| | - Erica C. Penn
- Experimental Therapeutics, Walter Reed Army Institute of Research, 2460 Linden Lane, Silver Spring, Maryland 20910, United States
| | - Jessey Erath
- Department of Microbiology, New York University School of Medicine, 430 East 29th Street, New York, New York 10010, United States
| | - Ana Rodriguez
- Department of Microbiology, New York University School of Medicine, 430 East 29th Street, New York, New York 10010, United States
| | - Richard J. Sciotti
- Experimental Therapeutics, Walter Reed Army Institute of Research, 2460 Linden Lane, Silver Spring, Maryland 20910, United States
| | - Robert F. Campbell
- Experimental Therapeutics, Walter Reed Army Institute of Research, 2460 Linden Lane, Silver Spring, Maryland 20910, United States
| | - James McKerrow
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093, United States
| | - Jair L. Siqueira-Neto
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093, United States
| | - Lori Ferrins
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States
| | - Michael P. Pollastri
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts 02115, United States
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4
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Gurney ME, Nugent RA, Mo X, Sindac JA, Hagen TJ, Fox D, O'Donnell JM, Zhang C, Xu Y, Zhang HT, Groppi VE, Bailie M, White RE, Romero DL, Vellekoop AS, Walker JR, Surman MD, Zhu L, Campbell RF. Design and Synthesis of Selective Phosphodiesterase 4D (PDE4D) Allosteric Inhibitors for the Treatment of Fragile X Syndrome and Other Brain Disorders. J Med Chem 2019; 62:4884-4901. [PMID: 31013090 DOI: 10.1021/acs.jmedchem.9b00193] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Novel pyridine- and pyrimidine-based allosteric inhibitors are reported that achieve PDE4D subtype selectivity through recognition of a single amino acid difference on a key regulatory domain, known as UCR2, that opens and closes over the catalytic site for cAMP hydrolysis. The design and optimization of lead compounds was based on iterative analysis of X-ray crystal structures combined with metabolite identification. Selectivity for the activated, dimeric form of PDE4D provided potent memory enhancing effects in a mouse model of novel object recognition with improved tolerability and reduced vascular toxicity over earlier PDE4 inhibitors that lack subtype selectivity. The lead compound, 28 (BPN14770), has entered midstage, human phase 2 clinical trials for the treatment of Fragile X Syndrome.
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Affiliation(s)
- Mark E Gurney
- Tetra Discovery Partners, Inc. , 38 Fulton Street West , Grand Rapids , Michigan 49503 , United States
| | - Richard A Nugent
- Tetra Discovery Partners, Inc. , 38 Fulton Street West , Grand Rapids , Michigan 49503 , United States
| | - Xuesheng Mo
- Tetra Discovery Partners, Inc. , 38 Fulton Street West , Grand Rapids , Michigan 49503 , United States
| | - Janice A Sindac
- Tetra Discovery Partners, Inc. , 38 Fulton Street West , Grand Rapids , Michigan 49503 , United States
| | - Timothy J Hagen
- Department of Chemistry and Biochemistry , Northern Illinois University , 1425 West Lincoln Highway , DeKalb , Illinois 60115 , United States
| | - David Fox
- Beryllium Discovery Corp. , 7869 NE Day Road West , Bainbridge Island , Washington 98110 , United States
| | - James M O'Donnell
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences , University at Buffalo, The State University of New York , Buffalo , New York 14214-8033 , United States
| | - Chong Zhang
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences , University at Buffalo, The State University of New York , Buffalo , New York 14214-8033 , United States
| | - Ying Xu
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences , University at Buffalo, The State University of New York , Buffalo , New York 14214-8033 , United States
| | - Han-Ting Zhang
- Departments of Behavioral Medicine & Psychiatry and Physiology, Pharmacology & Neuroscience, Rockefeller Neurosciences Institute , West Virginia University Health Sciences Center , 1 Medical Center Drive , Morgantown , West Virginia 26506 , United States
| | - Vincent E Groppi
- Michigan Drug Discovery, Life Sciences Institute , University of Michigan , 210 Washtenaw Avenue , Ann Arbor , Michigan 48103 , United States
| | - Marc Bailie
- INDS Inc. , 6111 Jackson Road, Suite 100 , Ann Arbor , Michigan 48103 , United States
| | - Ronald E White
- White Global Pharma Consultants , 31 Kinglet Drive , South Cranbury , New Jersey 08512 , United States
| | - Donna L Romero
- Pharma-Vation Consulting, LLC , 1201 Turnberry Ridge Court , Chesterfield , Missouri 63005 , United States
| | - A Samuel Vellekoop
- Albany Molecular Research, Inc. , 21 Corporate Circle , Albany , New York 12203 , United States
| | - Joel R Walker
- Albany Molecular Research, Inc. , 21 Corporate Circle , Albany , New York 12203 , United States
| | - Matthew D Surman
- Albany Molecular Research, Inc. , 21 Corporate Circle , Albany , New York 12203 , United States
| | - Lei Zhu
- Albany Molecular Research, Inc. , 21 Corporate Circle , Albany , New York 12203 , United States
| | - Robert F Campbell
- Albany Molecular Research, Inc. , 21 Corporate Circle , Albany , New York 12203 , United States
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5
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Frueh L, Li Y, Mather MW, Li Q, Pou S, Nilsen A, Winter RW, Forquer IP, Pershing AM, Xie LH, Smilkstein MJ, Caridha D, Koop DR, Campbell RF, Sciotti RJ, Kreishman-Deitrick M, Kelly JX, Vesely B, Vaidya AB, Riscoe MK. Alkoxycarbonate Ester Prodrugs of Preclinical Drug Candidate ELQ-300 for Prophylaxis and Treatment of Malaria. ACS Infect Dis 2017; 3:728-735. [PMID: 28927276 DOI: 10.1021/acsinfecdis.7b00062] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [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
ELQ-300 is a preclinical antimalarial drug candidate that is active against liver, blood, and transmission stages of Plasmodium falciparum. While ELQ-300 is highly effective when administered in a low multidose regimen, poor aqueous solubility and high crystallinity have hindered its clinical development. To overcome its challenging physiochemical properties, a number of bioreversible alkoxycarbonate ester prodrugs of ELQ-300 were synthesized. These bioreversible prodrugs are converted to ELQ-300 by host and parasite esterase action in the liver and bloodstream of the host. One such alkoxycarbonate prodrug, ELQ-331, is curative against Plasmodium yoelii with a single low dose of 3 mg/kg in a murine model of patent malaria infection. ELQ-331 is at least as fully protective as ELQ-300 in a murine malaria prophylaxis model when delivered 24 h before sporozoite inoculation at an oral dose of 1 mg/kg. Here, we show that ELQ-331 is a promising prodrug of ELQ-300 with improved physiochemical and metabolic properties and excellent potential for clinical formulation.
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Affiliation(s)
- Lisa Frueh
- Experimental Chemotherapy Laboratory, VA Medical Center (Mail code RD-33), 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States
- Department of Molecular Microbiology and
Immunology, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, United States
| | - Yuexin Li
- Experimental Chemotherapy Laboratory, VA Medical Center (Mail code RD-33), 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States
| | - Michael W. Mather
- Department
of Microbiology and Immunology, Drexel University, 2900 W. Queen Lane, Philadelphia, Pennsylvania 19129, United States
| | - Qigui Li
- Experimental
Therapeutics Branch, Military Malaria Research Program (MMRP), Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, Maryland 20910, United States
| | - Sovitj Pou
- Department of Molecular Microbiology and
Immunology, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, United States
| | - Aaron Nilsen
- Experimental Chemotherapy Laboratory, VA Medical Center (Mail code RD-33), 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States
| | - Rolf W. Winter
- Experimental Chemotherapy Laboratory, VA Medical Center (Mail code RD-33), 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States
| | - Isaac P. Forquer
- Experimental Chemotherapy Laboratory, VA Medical Center (Mail code RD-33), 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States
| | - April M. Pershing
- Department
of Microbiology and Immunology, Drexel University, 2900 W. Queen Lane, Philadelphia, Pennsylvania 19129, United States
| | - Lisa H. Xie
- Experimental
Therapeutics Branch, Military Malaria Research Program (MMRP), Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, Maryland 20910, United States
| | - Martin J. Smilkstein
- Experimental Chemotherapy Laboratory, VA Medical Center (Mail code RD-33), 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States
| | - Diana Caridha
- Experimental
Therapeutics Branch, Military Malaria Research Program (MMRP), Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, Maryland 20910, United States
| | - Dennis R. Koop
- Department of Physiology and Pharmacology, Oregon Health & Science University, 3181 S.W. Sam Jackson Park Road, Portland, Oregon 97239, United States
| | - Robert F. Campbell
- Experimental
Therapeutics Branch, Military Malaria Research Program (MMRP), Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, Maryland 20910, United States
| | - Richard J. Sciotti
- Experimental
Therapeutics Branch, Military Malaria Research Program (MMRP), Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, Maryland 20910, United States
| | - Mara Kreishman-Deitrick
- Experimental
Therapeutics Branch, Military Malaria Research Program (MMRP), Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, Maryland 20910, United States
| | - Jane X. Kelly
- Experimental Chemotherapy Laboratory, VA Medical Center (Mail code RD-33), 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States
| | - Brian Vesely
- Experimental
Therapeutics Branch, Military Malaria Research Program (MMRP), Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, Maryland 20910, United States
| | - Akhil B. Vaidya
- Department
of Microbiology and Immunology, Drexel University, 2900 W. Queen Lane, Philadelphia, Pennsylvania 19129, United States
| | - Michael K. Riscoe
- Experimental Chemotherapy Laboratory, VA Medical Center (Mail code RD-33), 3710 SW US Veterans Hospital Road, Portland, Oregon 97239, United States
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Campbell RF, Fitzpatrick K, Inghardt T, Karlsson O, Nilsson K, Reilly JE, Yet L. Enzymatic resolution of substituted mandelic acids. Tetrahedron Lett 2003. [DOI: 10.1016/s0040-4039(03)01270-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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7
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Feldman KS, Campbell RF. Efficient Stereo- and Regiocontrolled Alkene Photodimerization through Hydrogen Bond Enforced Preorganization in the Solid State. J Org Chem 2002. [DOI: 10.1021/jo00112a007] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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8
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Campbell RF, Hanna MW. The vanadyl ion as an electron paramagnetic resonance probe of micelle-liquid crystal systems. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100558a017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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10
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S. Feldman K, Liu Y, C. Saunders J, M. Masters K, F. Campbell R. Heterocycles in Organic Materials Chemistry. Synthesis of Di-, Tri-, and Tetraimide Polycarboxylic Acids for Use in Organic Network Assembly. HETEROCYCLES 2001. [DOI: 10.3987/com-01-9242] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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11
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Feldman KS, Campbell RF, West TR, Aloise AD, Giampetro DM. Modeling Chemical Vapor Deposition (CVD) Diamond Film Growth with Diamantane-Derived Radicals in Solution: Permissive Evidence in Support of the Garrison−Brenner Mechanism for Incorporation of Carbon into the Dimer Sites of the {100} Diamond Surface. J Org Chem 1999. [DOI: 10.1021/jo9911793] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ken S. Feldman
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Robert F. Campbell
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Theodore R. West
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Allen D. Aloise
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - David M. Giampetro
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
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12
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Feldman KS, Campbell RF, Saunders JC, Ahn C, Masters KM. Toward Covalently Linked Organic Networks: Model Studies and Connector Syntheses. J Org Chem 1997. [DOI: 10.1021/jo9714167] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ken S. Feldman
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Robert F. Campbell
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Joe C. Saunders
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Chuljin Ahn
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Katherine M. Masters
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
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13
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Campbell RF, Chasteen ND. An anion binding study of vanadyl(IV) human serotransferrin. Evidence for direct linkage to the metal. J Biol Chem 1977; 252:5996-6001. [PMID: 19460] [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: 12/12/2022] Open
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15
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Abstract
This study was undertaken to investigate the conformational states of the two metal sites in the human serum transferrin molecule. The 9.2 GHz electron paramagnetic resonance spectra of frozen solutions of divanadyl(IV) transferrin consist of a superposition of two sets of resonances, A and B, due to the magnetically nonequivalent binding environments of the VO2+ ion. Examination of the intensities of the A and B resonances as a function of pH from 6.0 to 10.7 reveals that they arise from two conformational states of the metal sites in which the geometrical arrangement and/or identity of one or more ligands in the first coordination sphere are different. From pH 7.5 to 9.0, the metal sites exist in A and B conformations but above pH 9.0 the A conformation. This transformation is coupled to the ionization of an apparently noncoordinating protein functional group with a pK - 10.0 +/- 0.1. Below pH 7.0, binding in the B conformation is rapidly lost, driven in part by the protonation of a functional group, possibly the anion, with a pK - 6.6 +/- 0.1. In 90% D2O, this pK is elevated to 7.8 +/- 0.1. At pH 6.0 in H2O, essentially one VO2+ ion remains bound to the protein with the metal site in the A conformation. Experiments with mixed VO2+ -Fe3+ transferrin complexes indicate that the same may be true of Fe3+. At pH 10.7, a new set of VO2+ resonances, labeled C, are observed; they possibly arise from a third conformation of the metal site. One bicarbonate or corbonate is required per VO2+ ion bound to the protein. 2.7 H+ are released per VO2+ bound in either the A or B conformations. The above results are discussed in terms of the "equivalence" and "nonequivalence" of the metal sites.
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