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Abbruzzetti S, Allegri A, Bidon-Chanal A, Ogata H, Soavi G, Cerullo G, Bruno S, Montali C, Luque FJ, Viappiani C. Electrostatic Tuning of the Ligand Binding Mechanism by Glu27 in Nitrophorin 7. Sci Rep 2018; 8:10855. [PMID: 30022039 PMCID: PMC6052033 DOI: 10.1038/s41598-018-29182-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 07/02/2018] [Indexed: 12/29/2022] Open
Abstract
Nitrophorins (NP) 1-7 are NO-carrying heme proteins found in the saliva of the blood-sucking insect Rhodnius prolixus. The isoform NP7 displays peculiar properties, such as an abnormally high isoelectric point, the ability to bind negatively charged membranes, and a strong pH sensitivity of NO affinity. A unique trait of NP7 is the presence of Glu in position 27, which is occupied by Val in other NPs. Glu27 appears to be important for tuning the heme properties, but its influence on the pH-dependent NO release mechanism, which is assisted by a conformational change in the AB loop, remains unexplored. Here, in order to gain insight into the functional role of Glu27, we examine the effect of Glu27 → Val and Glu27 → Gln mutations on the ligand binding kinetics using CO as a model. The results reveal that annihilation of the negative charge of Glu27 upon mutation reduces the pH sensitivity of the ligand binding rate, a process that in turn depends on the ionization of Asp32. We propose that Glu27 exerts a through-space electrostatic action on Asp32, which shifts the pKa of the latter amino acid towards more acidic values thus reducing the pH sensitivity of the transition between open and closed states.
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Affiliation(s)
- Stefania Abbruzzetti
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università degli Studi di Parma, Parco Area delle Scienze 7/A, 43124, Parma, Italy.
| | - Alessandro Allegri
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università degli Studi di Parma, Parco Area delle Scienze 7/A, 43124, Parma, Italy
| | - Axel Bidon-Chanal
- Department of Nutrition, Food Sciences and Gastronomy, Faculty of Pharmacy and Food Sciences and Institute of Biomedicine (IBUB), University of Barcelona, Avda. Prat de la Riba 171, Santa Coloma de Gramenet, Spain
| | - Hideaki Ogata
- Max-Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, D-45470, Mülheim an der Ruhr, Germany.,Institute of Low Temperature Science, Hokkaido University Kita19-Nishi8, Kita-ku, 060-0819, Sapporo, Japan
| | - Giancarlo Soavi
- Cambridge Graphene Centre, University of Cambridge, 9 JJ Thomson Avenue, Cambridge, CB3 OFA, UK
| | - Giulio Cerullo
- IFN-CNR, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milano, Italy
| | - Stefano Bruno
- Dipartimento di Scienze degli Alimenti e del Farmaco, Università degli Studi di Parma, Parco Area delle Scienze 27/A, 43124, Parma, Italy
| | - Chiara Montali
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università degli Studi di Parma, Parco Area delle Scienze 7/A, 43124, Parma, Italy
| | - F Javier Luque
- Department of Nutrition, Food Sciences and Gastronomy, Faculty of Pharmacy and Food Sciences and Institute of Biomedicine (IBUB), University of Barcelona, Avda. Prat de la Riba 171, Santa Coloma de Gramenet, Spain.
| | - Cristiano Viappiani
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università degli Studi di Parma, Parco Area delle Scienze 7/A, 43124, Parma, Italy.
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Knipp M, Ogata H, Soavi G, Cerullo G, Allegri A, Abbruzzetti S, Bruno S, Viappiani C, Bidon-Chanal A, Luque FJ. Structure and dynamics of the membrane attaching nitric oxide transporter nitrophorin 7. F1000Res 2015; 4:45. [PMID: 26167269 PMCID: PMC4482215 DOI: 10.12688/f1000research.6060.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/28/2015] [Indexed: 11/20/2022] Open
Abstract
Nitrophorins represent a unique class of heme proteins that are able to perform the delicate transportation and release of the free-radical gaseous messenger nitric oxide (NO) in a pH-triggered manner. Besides its ability to bind to phospholipid membranes, the N-terminus contains an additional Leu-Pro-Gly stretch, which is a unique sequence trait, and the heme cavity is significantly altered with respect to other nitrophorins. These distinctive features encouraged us to solve the X-ray crystallographic structures of NP7 at low and high pH and bound with different heme ligands (nitric oxide, histamine, imidazole). The overall fold of the lipocalin motif is well preserved in the different X-ray structures and resembles the fold of other nitrophorins. However, a chain-like arrangement in the crystal lattice due to a number of head-to-tail electrostatic stabilizing interactions is found in NP7. Furthermore, the X-ray structures also reveal ligand-dependent changes in the orientation of the heme, as well as in specific interactions between the A-B and G-H loops, which are considered to be relevant for the biological function of nitrophorins. Fast and ultrafast laser triggered ligand rebinding experiments demonstrate the pH-dependent ligand migration within the cavities and the exit route. Finally, the topological distribution of pockets located around the heme as well as from inner cavities present at the rear of the protein provides a distinctive feature in NP7, so that while a loop gated exit mechanism to the solvent has been proposed for most nitrophorins, a more complex mechanism that involves several interconnected gas hosting cavities is proposed for NP7.
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Affiliation(s)
- Markus Knipp
- Max-Planck-Institut für Chemische Energiekonversion, Mülheim an der Ruhr, 45470, Germany
| | - Hideaki Ogata
- Max-Planck-Institut für Chemische Energiekonversion, Mülheim an der Ruhr, 45470, Germany
| | - Giancarlo Soavi
- Dipartimento di Fisica, Politecnico di Milano, Milano, 20133, Italy
| | - Giulio Cerullo
- Dipartimento di Fisica, Politecnico di Milano, Milano, 20133, Italy
| | - Alessandro Allegri
- Dipartimento di Fisica e Scienze della Terra, Università di Parma, Parma, 43124, Italy
| | - Stefania Abbruzzetti
- Dipartimento di Bioscienze, Università di Parma, Parma, 43124, Italy ; NEST, Istituto Nanoscienze, Consiglio Nazionale delle Ricerche, Pisa, 56127, Italy
| | - Stefano Bruno
- Dipartimento di Farmacia, Università di Parma, Parma, 43124, Italy
| | - Cristiano Viappiani
- Dipartimento di Fisica e Scienze della Terra, Università di Parma, Parma, 43124, Italy ; NEST, Istituto Nanoscienze, Consiglio Nazionale delle Ricerche, Pisa, 56127, Italy
| | - Axel Bidon-Chanal
- Departament de Fisicoquímica, Facultat de Farmàcia and Institute of Biomedicine, Universitat de Barcelona, Santa Coloma de Gramenet, E-08921, Spain
| | - F Javier Luque
- Departament de Fisicoquímica, Facultat de Farmàcia and Institute of Biomedicine, Universitat de Barcelona, Santa Coloma de Gramenet, E-08921, Spain
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Xu T, Scafa N, Xu LP, Su L, Li C, Zhou S, Liu Y, Zhang X. Electrochemical Sensors for Nitric Oxide Detection in Biological Applications. ELECTROANAL 2014. [DOI: 10.1002/elan.201300564] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Pattillo CB, Bir S, Rajaram V, Kevil CG. Inorganic nitrite and chronic tissue ischaemia: a novel therapeutic modality for peripheral vascular diseases. Cardiovasc Res 2010; 89:533-41. [PMID: 20851809 DOI: 10.1093/cvr/cvq297] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Ischaemic tissue damage represents the ultimate form of tissue pathophysiology due to cardiovascular disease, which is the leading cause of morbidity and mortality across the globe. A significant amount of basic research and clinical investigation has been focused on identifying cellular and molecular pathways to alleviate tissue damage and dysfunction due to ischaemia and subsequent reperfusion. Over many years, the gaseous molecule nitric oxide (NO) has emerged as an important regulator of cardiovascular health as well as protector against tissue ischaemia and reperfusion injury. However, clinical translation of NO therapy for these pathophysiological conditions has not been realized for various reasons. Work from our laboratory and several others suggests that a new form of NO-associated therapy may be possible through the use of nitrite anion (sodium nitrite), a prodrug which can be reduced to NO in ischaemic tissues. In this manner, nitrite anion serves as a highly selective NO donor in ischaemic tissues without substantially altering otherwise normal tissue. This surprising and novel discovery has reinvigorated hopes for effectively restoring NO bioavailability in vulnerable tissues while continuing to reveal the complexity of NO biology and metabolism within the cardiovascular system. However, some concerns may exist regarding the effect of nitrite on carcinogenesis. This review highlights the emergence of nitrite anion as a selective NO prodrug for ischaemic tissue disorders and discusses the potential therapeutic utility of this agent for peripheral vascular disease.
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Affiliation(s)
- Christopher B Pattillo
- Department of Pathology and Cardiology, LSU Health Sciences Center-Shreveport, 1501 Kings Hwy, Shreveport, LA 71130, USA
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