Robert Ryan Geyer

Pós-doutorado

Formação complementar

Idiomas

Áreas de atuação

Organização de eventos

Orientou

Produções bibliográficas

• ZHAO, PAN ; GEYER, R. RYAN ; BORON, WALTER F. . A Novel Stopped-Flow Assay for Quantitating Carbonic-Anhydrase Activity and Assessing Red-Blood-Cell Hemolysis. Frontiers in Physiology , v. 8, p. 1-15, 2017.

• TAIRUM, CARLOS A. ; SANTOS, MELINA CARDOSO ; BREYER, CARLOS A. ; GEYER, R. RYAN ; NIEVES, CECILIA J. ; PORTILLO-LEDESMA, STEPHANIE ; FERRER-SUETA, GERARDO ; TOLEDO, JOSÉ CARLOS ; TOYAMA, MARCOS H. ; AUGUSTO, OHARA ; NETTO, LUIS E. S. ; DE OLIVEIRA, MARCOS A. . Catalytic Thr or Ser Residue Modulates Structural Switches in 2-Cys Peroxiredoxin by Distinct Mechanisms. Scientific Reports , v. 6, p. 33133, 2016.

• GEYER, R. R. ; MUSA-AZIZ, R. ; ENKAVI, G. ; MAHINTHICHAICHAN, P. ; TAJKHORSHID, E. ; BORON, W. F. . Movement of NH3 through the Human Urea Transporter B (UT-B): A New Gas Channel. AJP: Renal Physiology , v. 304, p. F1447-F1457, 2013.

• GEYER, R. RYAN ; PARKER, MARK D. ; TOYE, ASHLEY M. ; BORON, WALTER F. ; MUSA-AZIZ, RAIF . Relative CO2/NH3 Permeabilities of Human RhAG, RhBG and RhCG. The Journal of Membrane Biology (Print) , v. 246, p. x-x, 2013.

• GEYER, R. R. ; MUSA-AZIZ, R. ; QIN, X. ; BORON, W. F. . Relative CO2/NH3 selectivities of mammalian aquaporins 0-9. American Journal of Physiology. Cell Physiology , v. 304, p. C985-C994, 2013.

• PROCHASKA, LAWRENCE J. ; GEYER, ROBERT R. ; HOSLER, JONATHAN P. ; THOMPSON, AUDIE ; VARANASI, LAKSHMAN ; ALTER, GERALD M. ; LIU, AIMIN . Suicide Inactivation in Rhodobacter Sphaeroides Cytochrome c Oxidase Lacking Subunit III Coincides with Release of CuB and Major Conformational Changes in Subunit I. Biophysical Journal (Print) , v. 102, p. 574a, 2012.

• PROCHASKA, LAWRENCE J. ; CVETKOV, TERESA L. ; GEYER, R. RYAN . Structural and Functional Effects of C-Terminal Truncations in Cytochrome c Oxidase Subunit III from Rhodobacter Sphaeroides. Biophysical Journal (Print) , v. 100, p. 458a, 2011.

• NGUYEN, XUAN-THAO ; PABARUE, HUGH A. ; RYAN GEYER, R. ; SHROYER, LOIS A. ; ESTEY, LISA A. ; PARILO, MIGUEL ; WILSON, KATHRYN S. ; PROCHASKA, LAWRENCE J. . Biochemical and biophysical properties of purified phospholipid vesicles containing bovine heart cytochrome c oxidase. Protein Expression and Purification (Print) , v. 26, p. 122-130, 2002.

• SHAW, SHRUTI ; GEYER, RYAN ; ALTER, GERALD M . Dissociation of mitochondrial malate dehydrogenase into active soluble subunits. Biochimica et Biophysica Acta. Protein Structure and Molecular Enzymology (Cessou em 2002. Cont. ISSN 1570-9639 Biochimica et Biophysica Acta. Protein , v. 1478, p. 248-256, 2000.

• GEYER, R. R. ; MUSA-AZIZ, R. ; BORON, W. F. . Evidence that DIDS crosslinks Aquaporin 1 monomers. In: Federation of American Societies for Experimental Biology, 2011. The FASEB Journal, 2011.

• GEYER, R. R. . Investigating the role of subunit III in the structure and function of Rhodobacter sphaeroides cytochrome c oxidase. In: Wright State University, 2007. Wright State University, 2007.

• GEYER, R. R. ; PROCHASKA, LAWRENCE J. . Further evidence for subunit III stabilizing the quaternary structure of Rhodobacter sphaeroides cytochrome c oxidase.. In: Biophysical Society, 2004. BIOPHYSICAL JOURNAL, 2004.

• GEYER, R. R. ; PROCHASKA, LAWRENCE J. . The effect of mutagenesis of highly conserved amino acid residues in subunit III of Rhodobacter sphaeroides cytochrome c oxidase on the structure and function of the enzyme. In: Biophysical Society, 2002. BIOPHYSICAL JOURNAL, 2002.

• PROCHASKA, LAWRENCE J. ; GEYER, R. R. ; OGUNJIMI, K. . Analysis of the Structural and Functional Role of the Dicyclohexylcarbodiimide (DCCD) Binding Site (E90-H212-Y246) in Subunit III of Bovine Heart and Rhodobacter Sphaeroides Cytochrome c Oxidase using Mutagenesis and Chemical Modification. In: Biophysical Society, 2017. Biophysical Journal, 2017.

• ZHAO, PAN ; GEYER, R. R. ; SALAMEH, A. I. ; MOSS, F. J. ; BORON, W. F. . Oxygen Channels in Red Blood Cells. In: Federation of American Societies for Experimental Biology, 2016. The FASEB Journal, 2016.

• KABUTOMORI, J. ; GEYER, R. R. ; MUSA-AZIZ, R. . The osmotic H2O-permeability of human urea transporters UT-A1, A2, A3 and B in Rana catesbeiana oocytes. In: Federation of American Societies for Experimental Biology, 2016. The FASEB Journal, 2016.

• KABUTOMORI, J. ; GEYER, R. R. ; MUSA-AZIZ, R. . Rana catesbeiana Oocytes: An Alternative To The Xenopus laevis Heterologous Expression System For Ammonia Transporters. In: Federation of American Societies for Experimental Biology, 2015. The FASEB Journal, 2015.

• GEYER, R. R. ; COELHO, FR. ; AUGUSTO, O. . Characterization of human superoxide dismutase 1 overexpressed in the methylotrophic yeast Pichia pastoris. In: 23rd nternational Union of Biochemistry and Molecular Biology Meeting, 2015. Biochemistry and Molecular Biology Journal, 2015.

• TAIRUM, CARLOS A. ; GEYER, R. R. ; AUGUSTO, O. ; NETTO, LUIS E. S. ; OLIVEIRA, MA. . Involvement of catalytical triad Thr44 of Tsa1 Saccharomyces cerevisiae in decamer stabilization and catalysis. In: 23rd International Union of Biochemistry and Molecular Biology, 2015. Biochemistry and Molecular Biology Journal, 2015.

• Zurlo FM ; TAIRUM, CARLOS A. ; GEYER, R. R. ; AUGUSTO, O. ; NETTO, LUIS E. S. ; OLIVEIRA, MA. . Determination of yeast cytosolic peroxiredoxin reduction rates by thioredoxins and Prx overoxidation through fluorescence approaches. In: 23rd International Union of Biochemistry and Molecular Biology, 2015. International Union of Biochemistry and Molecular Biology Journal.

• Linares E ; FONTES, RS. ; NEVES, SMP. ; GEYER, R. R. ; ALVES-LIMA, C. ; AUGUSTO, O. . Changes in transgene copy number in a hSOD1G93A ALS rat model. In: 23rd International Union of Biochemistry and Molecular Biology, 2015. International Union of Biochemistry and Molecular Biology Journal, 2015.

• PROCHASKA, LAWRENCE J. ; GEYER, R. RYAN . Structural and Functional Effects of C-Terminal Truncations in Cytochrome c Oxidase Subunit III from Rhodobacter Sphaeroides. In: Biophysical Society, 2011. Biophysical Journal.

• MUSA-AZIZ, RAIF ; GEYER, R. R. ; BORON, W. F. . Relative CO2/NH3 permeabilities of several members of the mammalian Aquaporin family: bAQP0, hAQP1, hAQP2, rAQP3, rAQP4-M1, rAQP4-M23, and hAQP8. In: Federation of American Societies for Experimental Biology, 2011. The FASEB Journal, 2011.

• GEYER, R. R. ; TOYE, ASHLEY M. ; PARKER, MARK D. ; BORON, W. F. ; MUSA-AZIZ, R. . NH3 Permeability of Human RhAG, RhBG, and RhCG. In: American Society of Nephrology Meeting, 2010. Journal of the American Society of Nephrology, 2010.

• MUSA-AZIZ, R. ; GEYER, R. R. ; SHAIKH, S. ; TAJKHORSHID, E. ; BORON, W. F. . Investigating the Mechanism of CO2 Transport through human AQP1. In: Americal Society of Nephrology Meeting, 2009. Resultados da pesquisa Journal of the American Society of Nephrology, 2009.

• GEYER, R. R. ; MUSA-AZIZ, R. ; BORON, W. F. . Proteomics Approach for Identifying the DIDS-reaction Site of human Aquaporin 1. In: American Society of Nephrology Meeting, 2009. Journal of the American Society of Nephrology, 2009.

• PROCHASKA, LAWRENCE J. ; GEYER, R. R. . Utilization of MALDI-TOF mass spectroscopy to detect sites of dicyclohexylcarbodiimide (DCCD) modification in bovine heart and Rhodobacter sphaeroides cytochrome c oxidases.. In: Biophysical Soceity, 2007. Biophysical Journal, 2007.

• GEYER, R. R. ; PROCHASKA, LAWRENCE J. . Cytochrome c oxidase subunit I assumes an alternative conformation in the absence of subunit III.. In: Biophysical Society, 2005. BIOPHYSICAL JOURNAL 88, 2005.

• Peixoto ÁS ; GEYER, R. R. ; IQBAL, A. ; MORETTI, A. ; LAURINDO, FRM ; AUGUSTO, O. . Rapid oxidation of the dithiol redox motifs of protein disulfide isomerase by peroxynitrite precedes enzyme nitration, inactivation and aggregation. JOURNAL OF BIOLOGICAL CHEMISTRY , 2018.

• Zhao P ; GEYER, R. R. ; SALAMEH, A. I. ; MEYERSON, H. J. ; CARTRON, J. ; GROS, G. ; OCCHIPINTI, R. ; MOSS, F. J. ; BORON, W. F. . Role of channels in the oxygen permeability of red blood cells. Nature , 2018.

Projetos de pesquisa

• 2014 - 2017

  Lithobates catesbeianus (American Bullfrog) Oocytes: A Novel Heterologous Expression System for Aquaporins, Projeto certificado pelo(a) coordenador(a) Raif Musa Aziz em 11/10/2017., Descrição: This work has generated one manuscript that has been submitted to Journal Experimental Biology. , Situação: Concluído; Natureza: Pesquisa. , Integrantes: Robert Ryan Geyer - Integrante / Raif Musa-Aziz - Coordenador.

• 2013 - 2016

  Oxidation and aggregation of human superoxide dismutase 1 resulting from its bicarbonate-dependent peroxidase activity, Descrição: This work generate two manuscripts. One manuscript published during this fellowship investigated the mechanism by which highly conserved amino acid residues modulate the structure of 2-Cys peroxiredoxin. Another manuscript, currently being reviewed, investigated how ONOO? promotes non-specific oxidation, nitration, inactivation, and aggregation through the rapid oxidation of the dithiol redox motifs in protein disulfide isomerase.. , Situação: Concluído; Natureza: Pesquisa. , Integrantes: Robert Ryan Geyer - Integrante / AUGUSTO, OHARA - Coordenador.

• 2010 - 2017

  Role of membrane proteins in oxygen transport in red blood cells, Descrição: Identification of O2 channels in red blood cells (RBCs). Here I concisely summarize the project?s past accomplishments: 1) Developed a stopped-flow absorbance spectroscopy approach to monitor the rate of oxygenation and deoxygenation of RBCs in the presence and absence of inhibitors, as well as in knockout mice. 2) Found that knocking out AQP1 or RhAG has only minor effects on O2 efflux. 3) Found that a combination of small-molecule inhibitors can reduce the rate of O2 efflux by approximately 70%. 4) Obtained preliminary evidence that different strains of ?wild-type? mice may have different baseline O2 permeabilities. 5) We discovered that modest RBC lysis substantially increases the rate of deoxygenation, which could lead to an underestimation of inhibition evidenced in knockouts and with inhibitors. Thus we are developing a novel assay using stopped flow fluorescence spectroscopy to monitor the release of carbonic anhydrase II (CAII). This will allow us to back correct for cell lysis and obtain a more accurate determination of inhibition.. , Situação: Concluído; Natureza: Pesquisa. , Integrantes: Robert Ryan Geyer - Coordenador / Walter F. Boron - Integrante., Financiador(es): Office of Naval Research - Auxílio financeiro.

• 2010 - 2013

  Characterize H2O, gas (NH3 and CO2), and urea transport properties of ten AQPs (AQPs 0-9), three rhesus (Rh) proteins, and urea transporter B (UT-B) in Xenopus oocytes, Descrição: This work has generated three published papers: (1) Movement of NH3 through the Human Urea Transporter B (UT-B): A New Gas Channel16 and (2) CO2/NH3 selectivities of mammalian Aquaporins 0-9, and 3) Relative CO2/NH3 permeabilities of human RhAG, RhBG, and RhCG.. , Situação: Concluído; Natureza: Pesquisa. , Integrantes: Robert Ryan Geyer - Integrante / Raif Musa-Aziz - Integrante / Walter F. Boron - Coordenador., Financiador(es): Office of Naval Research - Auxílio financeiro / Fundação de Amparo à Pesquisa do Estado de São Paulo - Auxílio financeiro.

• 2008 - 2013

  Mechanism of CO2 and NH3 transport through human Aquaporin 1: Evidence for parallel CO2 pathways, Descrição: AQP1 has two distinct pathways for CO2 transport. The first pathway is the monomeric aquapore that is blocked by the organic mercury derivative pCMBS, which covalently reacts with Cys-189 at the external mouth of the monomeric AQP1 aquapore. The second pathway remains unidentified and is blocked by DIDS, the anion transporter inhibitor that contains two isothiocyanate groups which can attack and covalently crosslink primary amines (ie. Lysines). Using biochemical techniquesprotein expression and purification, surface labeling, and proteomicsI have been attempting to identify the DIDS binding site in AQP1 towards the goal of elucidating of the molecular mechanism of CO2 transport through the protein.. , Situação: Concluído; Natureza: Pesquisa. , Integrantes: Robert Ryan Geyer - Coordenador / Walter F Boron - Integrante., Financiador(es): Office of Naval Research - Auxílio financeiro.

• 2008 - 2008

  Overexpressing the juxtamembrane region of epidermal growth factor receptor (EGFR) and calmodulin, Descrição: The goal was to determine if the two proteins interacted and the second goal was to identify the region where calmodulin binds.. , Situação: Concluído; Natureza: Pesquisa. , Integrantes: Robert Ryan Geyer - Coordenador / Frank Sönnichsen - Integrante.