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Safari C, Ghosh S, Andersson R, Johannesson J, Båth P, Uwangue O, Dahl P, Zoric D, Sandelin E, Vallejos A, Nango E, Tanaka R, Bosman R, Börjesson P, Dunevall E, Hammarin G, Ortolani G, Panman M, Tanaka T, Yamashita A, Arima T, Sugahara M, Suzuki M, Masuda T, Takeda H, Yamagiwa R, Oda K, Fukuda M, Tosha T, Naitow H, Owada S, Tono K, Nureki O, Iwata S, Neutze R, Brändén G. Time-resolved serial crystallography to track the dynamics of carbon monoxide in the active site of cytochrome c oxidase. SCIENCE ADVANCES 2023; 9:eadh4179. [PMID: 38064560 PMCID: PMC10708180 DOI: 10.1126/sciadv.adh4179] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 11/09/2023] [Indexed: 12/18/2023]
Abstract
Cytochrome c oxidase (CcO) is part of the respiratory chain and contributes to the electrochemical membrane gradient in mitochondria as well as in many bacteria, as it uses the energy released in the reduction of oxygen to pump protons across an energy-transducing biological membrane. Here, we use time-resolved serial femtosecond crystallography to study the structural response of the active site upon flash photolysis of carbon monoxide (CO) from the reduced heme a3 of ba3-type CcO. In contrast with the aa3-type enzyme, our data show how CO is stabilized on CuB through interactions with a transiently ordered water molecule. These results offer a structural explanation for the extended lifetime of the CuB-CO complex in ba3-type CcO and, by extension, the extremely high oxygen affinity of the enzyme.
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Affiliation(s)
- Cecilia Safari
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, SE-40530 Gothenburg, Sweden
| | - Swagatha Ghosh
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, SE-40530 Gothenburg, Sweden
| | - Rebecka Andersson
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, SE-40530 Gothenburg, Sweden
| | - Jonatan Johannesson
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, SE-40530 Gothenburg, Sweden
| | - Petra Båth
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, SE-40530 Gothenburg, Sweden
| | - Owens Uwangue
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, SE-40530 Gothenburg, Sweden
| | - Peter Dahl
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, SE-40530 Gothenburg, Sweden
| | - Doris Zoric
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, SE-40530 Gothenburg, Sweden
| | - Emil Sandelin
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, SE-40530 Gothenburg, Sweden
| | - Adams Vallejos
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, SE-40530 Gothenburg, Sweden
| | - Eriko Nango
- RIKEN SPring-8 Center, 1-1-1 Kuoto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Yoshidakonoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Rie Tanaka
- RIKEN SPring-8 Center, 1-1-1 Kuoto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Yoshidakonoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Robert Bosman
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, SE-40530 Gothenburg, Sweden
| | - Per Börjesson
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, SE-40530 Gothenburg, Sweden
| | - Elin Dunevall
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, SE-40530 Gothenburg, Sweden
| | - Greger Hammarin
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, SE-40530 Gothenburg, Sweden
| | - Giorgia Ortolani
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, SE-40530 Gothenburg, Sweden
| | - Matthijs Panman
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, SE-40530 Gothenburg, Sweden
| | - Tomoyuki Tanaka
- RIKEN SPring-8 Center, 1-1-1 Kuoto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Ayumi Yamashita
- RIKEN SPring-8 Center, 1-1-1 Kuoto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Toshi Arima
- RIKEN SPring-8 Center, 1-1-1 Kuoto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Michihiro Sugahara
- RIKEN SPring-8 Center, 1-1-1 Kuoto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Mamoru Suzuki
- Laboratory of Supramolecular Crystallography, Research Center for Structural and Functional Proteomics, Institute for Protein Research, Osaka University, Osaka, Japan
| | - Tetsuya Masuda
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Japan
| | - Hanae Takeda
- RIKEN SPring-8 Center, 1-1-1 Kuoto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
- Graduate School of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigori, Ako, Hyogo 678-1297, Japan
| | - Raika Yamagiwa
- RIKEN SPring-8 Center, 1-1-1 Kuoto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
- Graduate School of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigori, Ako, Hyogo 678-1297, Japan
| | - Kazumasa Oda
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Masahiro Fukuda
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Takehiko Tosha
- RIKEN SPring-8 Center, 1-1-1 Kuoto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Hisashi Naitow
- RIKEN SPring-8 Center, 1-1-1 Kuoto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Shigeki Owada
- RIKEN SPring-8 Center, 1-1-1 Kuoto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - Kensuke Tono
- RIKEN SPring-8 Center, 1-1-1 Kuoto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - Osamu Nureki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - So Iwata
- RIKEN SPring-8 Center, 1-1-1 Kuoto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Yoshidakonoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Richard Neutze
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, SE-40530 Gothenburg, Sweden
| | - Gisela Brändén
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, SE-40530 Gothenburg, Sweden
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2
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Jancura D, Tomkova A, Sztachova T, Berka V, Fabian M. Examination of 'high-energy' metastable state of the oxidized (O H) bovine cytochrome c oxidase: Proton uptake and reaction with H 2O 2. Arch Biochem Biophys 2023; 747:109758. [PMID: 37748626 DOI: 10.1016/j.abb.2023.109758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 09/04/2023] [Accepted: 09/15/2023] [Indexed: 09/27/2023]
Abstract
Reoxidized cytochrome c oxidase appears to be in a 'high-energy' metastable state (OH) in which part of the energy released in the redox reactions is stored. The OH is supposed to relax to the resting 'as purified' oxidized state (O) in a time exceeding 200 ms. The catalytic heme a3-CuB center of these two forms should differ in a protonation and ligation state and the transition of OH-to-O is suggested to be associated with a proton transfer into this center. Employing a stopped-flow and UV-Vis absorption spectroscopy we investigated a proton uptake during the predicted relaxation of OH. It is shown, using a pH indicator phenol red, that from the time when the oxidation of the fully reduced CcO is completed (∼25 ms) up to ∼10 min, there is no uptake of a proton from the external medium (pH 7.8). Moreover, interactions of the assumed OH, generated 100 ms after oxidation of the fully reduced CcO, and the O with H2O2 (1 mM), result in the formation of two ferryl intermediates of the catalytic center, P and F, with very similar kinetics and the amounts of the formed ferryl states in both cases. These results implicate that the relaxation time of the catalytic center during the OH-to-O transition is either shorter than 100 ms or there is no difference in the structure of heme a3-CuB center of these two forms.
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Affiliation(s)
- D Jancura
- Department of Biophysics, Faculty of Science, University of P. J. Safarik, Jesenna 5, 041 54, Kosice, Slovak Republic
| | - A Tomkova
- Department of Biophysics, Faculty of Science, University of P. J. Safarik, Jesenna 5, 041 54, Kosice, Slovak Republic
| | - T Sztachova
- Department of Biophysics, Faculty of Science, University of P. J. Safarik, Jesenna 5, 041 54, Kosice, Slovak Republic
| | - V Berka
- Department of Internal Medicine, University of Texas Health Science Center, 77030, Houston, Texas, USA
| | - M Fabian
- Center for Interdisciplinary Biosciences, Technology and Innovation Park, University of P. J. Safarik, Jesenna 5, 041 54, Kosice, Slovak Republic.
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3
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Ishigami I, Sierra RG, Su Z, Peck A, Wang C, Poitevin F, Lisova S, Hayes B, Moss FR, Boutet S, Sublett RE, Yoon CH, Yeh SR, Rousseau DL. Structural insights into functional properties of the oxidized form of cytochrome c oxidase. Nat Commun 2023; 14:5752. [PMID: 37717031 PMCID: PMC10505203 DOI: 10.1038/s41467-023-41533-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 09/07/2023] [Indexed: 09/18/2023] Open
Abstract
Cytochrome c oxidase (CcO) is an essential enzyme in mitochondrial and bacterial respiration. It catalyzes the four-electron reduction of molecular oxygen to water and harnesses the chemical energy to translocate four protons across biological membranes. The turnover of the CcO reaction involves an oxidative phase, in which the reduced enzyme (R) is oxidized to the metastable OH state, and a reductive phase, in which OH is reduced back to the R state. During each phase, two protons are translocated across the membrane. However, if OH is allowed to relax to the resting oxidized state (O), a redox equivalent to OH, its subsequent reduction to R is incapable of driving proton translocation. Here, with resonance Raman spectroscopy and serial femtosecond X-ray crystallography (SFX), we show that the heme a3 iron and CuB in the active site of the O state, like those in the OH state, are coordinated by a hydroxide ion and a water molecule, respectively. However, Y244, critical for the oxygen reduction chemistry, is in the neutral protonated form, which distinguishes O from OH, where Y244 is in the deprotonated tyrosinate form. These structural characteristics of O provide insights into the proton translocation mechanism of CcO.
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Affiliation(s)
- Izumi Ishigami
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Raymond G Sierra
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Zhen Su
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
- Department of Applied Physics, Stanford University, Stanford, CA, 94305, USA
| | - Ariana Peck
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Cong Wang
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Frederic Poitevin
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Stella Lisova
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Brandon Hayes
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Frank R Moss
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
- Altos Labs, Redwood City, CA, 94065, USA
| | - Sébastien Boutet
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Robert E Sublett
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Chun Hong Yoon
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Syun-Ru Yeh
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, 10461, USA.
| | - Denis L Rousseau
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, 10461, USA.
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4
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Huang D, Jing G, Zhu S. Regulation of Mitochondrial Respiration by Hydrogen Sulfide. Antioxidants (Basel) 2023; 12:1644. [PMID: 37627639 PMCID: PMC10451548 DOI: 10.3390/antiox12081644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/10/2023] [Accepted: 08/14/2023] [Indexed: 08/27/2023] Open
Abstract
Hydrogen sulfide (H2S), the third gasotransmitter, has positive roles in animals and plants. Mitochondria are the source and the target of H2S and the regulatory hub in metabolism, stress, and disease. Mitochondrial bioenergetics is a vital process that produces ATP and provides energy to support the physiological and biochemical processes. H2S regulates mitochondrial bioenergetic functions and mitochondrial oxidative phosphorylation. The article summarizes the recent knowledge of the chemical and biological characteristics, the mitochondrial biosynthesis of H2S, and the regulatory effects of H2S on the tricarboxylic acid cycle and the mitochondrial respiratory chain complexes. The roles of H2S on the tricarboxylic acid cycle and mitochondrial respiratory complexes in mammals have been widely studied. The biological function of H2S is now a hot topic in plants. Mitochondria are also vital organelles regulating plant processes. The regulation of H2S in plant mitochondrial functions is gaining more and more attention. This paper mainly summarizes the current knowledge on the regulatory effects of H2S on the tricarboxylic acid cycle (TCA) and the mitochondrial respiratory chain. A study of the roles of H2S in mitochondrial respiration in plants to elucidate the botanical function of H2S in plants would be highly desirable.
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Affiliation(s)
| | | | - Shuhua Zhu
- College of Chemistry and Material Science, Shandong Agricultural University, Taian 271018, China; (D.H.); (G.J.)
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5
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Makita H, Simon PS, Kern J, Yano J, Yachandra VK. Combining on-line spectroscopy with synchrotron and X-ray free electron laser crystallography. Curr Opin Struct Biol 2023; 80:102604. [PMID: 37148654 PMCID: PMC10793627 DOI: 10.1016/j.sbi.2023.102604] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 03/22/2023] [Accepted: 04/05/2023] [Indexed: 05/08/2023]
Abstract
With the recent advances in serial crystallography methods at both synchrotron and X-ray free electron laser sources, more details of intermediate or transient states of the catalytic reactions are being revealed structurally. These structural studies of reaction dynamics drive the need for on-line in crystallo spectroscopy methods to complement the crystallography experiment. The recent applications of combined spectroscopy and crystallography methods enable on-line determination of in crystallo reaction kinetics and structures of catalytic intermediates, sample integrity, and radiation-induced sample modifications, if any, as well as heterogeneity of crystals from different preparations or sample batches. This review describes different modes of spectroscopy that are combined with the crystallography experiment at both synchrotron and X-ray free-electron laser facilities, and the complementary information that each method can provide to facilitate the structural study of enzyme catalysis and protein dynamics.
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Affiliation(s)
- Hiroki Makita
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Philipp S Simon
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Jan Kern
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
| | - Junko Yano
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
| | - Vittal K Yachandra
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
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6
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Ishigami I, Sierra RG, Su Z, Peck A, Wang C, Poitevin F, Lisova S, Hayes B, Moss FR, Boutet S, Sublett RE, Yoon CH, Yeh SR, Rousseau DL. Structural basis for functional properties of cytochrome c oxidase. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.20.530986. [PMID: 36993562 PMCID: PMC10055264 DOI: 10.1101/2023.03.20.530986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
Abstract
Cytochrome c oxidase (CcO) is an essential enzyme in mitochondrial and bacterial respiration. It catalyzes the four-electron reduction of molecular oxygen to water and harnesses the chemical energy to translocate four protons across biological membranes, thereby establishing the proton gradient required for ATP synthesis1. The full turnover of the CcO reaction involves an oxidative phase, in which the reduced enzyme (R) is oxidized by molecular oxygen to the metastable oxidized OH state, and a reductive phase, in which OH is reduced back to the R state. During each of the two phases, two protons are translocated across the membranes2. However, if OH is allowed to relax to the resting oxidized state (O), a redox equivalent to OH, its subsequent reduction to R is incapable of driving proton translocation2,3. How the O state structurally differs from OH remains an enigma in modern bioenergetics. Here, with resonance Raman spectroscopy and serial femtosecond X-ray crystallography (SFX)4, we show that the heme a3 iron and CuB in the active site of the O state, like those in the OH state5,6, are coordinated by a hydroxide ion and a water molecule, respectively. However, Y244, a residue covalently linked to one of the three CuB ligands and critical for the oxygen reduction chemistry, is in the neutral protonated form, which distinguishes O from OH, where Y244 is in the deprotonated tyrosinate form. These structural characteristics of O provide new insights into the proton translocation mechanism of CcO.
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Affiliation(s)
- Izumi Ishigami
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461 USA
| | - Raymond G. Sierra
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 USA
| | - Zhen Su
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 USA
- Department of Applied Physics, Stanford University, Stanford, CA 94305 USA
| | - Ariana Peck
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 USA
| | - Cong Wang
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 USA
| | - Frederic Poitevin
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 USA
| | - Stella Lisova
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 USA
| | - Brandon Hayes
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 USA
| | - Frank R. Moss
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 USA
| | - Sébastien Boutet
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 USA
| | - Robert E. Sublett
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 USA
| | - Chun Hong Yoon
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 USA
| | - Syun-Ru Yeh
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461 USA
| | - Denis L. Rousseau
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461 USA
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Leitgeb U, Furtmüller PG, Hofbauer S, Brito JA, Obinger C, Pfanzagl V. The staphylococcal inhibitory protein SPIN binds to human myeloperoxidase with picomolar affinity but only dampens halide oxidation. J Biol Chem 2022; 298:102514. [PMID: 36150500 DOI: 10.1016/j.jbc.2022.102514] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 09/15/2022] [Accepted: 09/17/2022] [Indexed: 10/31/2022] Open
Abstract
The heme enzyme myeloperoxidase (MPO) is one of the key players in the neutrophil-mediated killing of invading pathogens as part of the innate immune system. MPO generates antimicrobial oxidants which indiscriminately and effectively kill phagocytosed pathogens. Staphylococcus aureus however is able to escape this fate, in part by secreting a small protein called SPIN (Staphylococcal Peroxidase Inhibitor), which specifically targets and inhibits MPO in a structurally complex manner. Here we present the first crystal structures of the complex of SPIN-aureus and a truncated version (SPIN-truncated) with mature dimeric leukocyte MPO. We unravel the contributions of the two domains to the kinetics and thermodynamics of SPIN-aureus binding to MPO by using a broad array of complementary biochemical and biophysical methods. The C-terminal "recognition" domain is shown to mediate specific binding to MPO, while interaction of the N-terminal "inhibitory" domain is guided mainly by hydrophobic effects and thus is less sequence-dependent. We found that inhibition of MPO is achieved by reducing substrate migration, but SPIN-aureus cannot completely block MPO activity. Its' effectiveness is inversely related to substrate size, with no discernible dependence on other factors. Thus, SPIN-aureus is an extremely high-affinity inhibitor and highly efficient for substrates larger than halogens. As aberrant MPO activity is implicated in a number of chronic inflammatory diseases, SPIN-aureus is the first promising protein inhibitor for specific inhibition of human MPO.
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Affiliation(s)
- Urban Leitgeb
- University of Natural Resources and Life Sciences, Vienna, Department of Chemistry, Institute of Biochemistry, Muthgasse 18, 1190 Vienna, Austria
| | - Paul G Furtmüller
- University of Natural Resources and Life Sciences, Vienna, Department of Chemistry, Institute of Biochemistry, Muthgasse 18, 1190 Vienna, Austria
| | - Stefan Hofbauer
- University of Natural Resources and Life Sciences, Vienna, Department of Chemistry, Institute of Biochemistry, Muthgasse 18, 1190 Vienna, Austria
| | - Jose A Brito
- Universidade Nova de Lisboa, Instituto de Tecnologia Química e Biológica António Xavier, 2780-157 Oeiras, Portugal
| | - Christian Obinger
- University of Natural Resources and Life Sciences, Vienna, Department of Chemistry, Institute of Biochemistry, Muthgasse 18, 1190 Vienna, Austria
| | - Vera Pfanzagl
- University of Natural Resources and Life Sciences, Vienna, Department of Chemistry, Institute of Biochemistry, Muthgasse 18, 1190 Vienna, Austria
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