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Lewin MR, Carter RW, Matteo IA, Samuel SP, Rao S, Fry BG, Bickler PE. Varespladib in the Treatment of Snakebite Envenoming: Development History and Preclinical Evidence Supporting Advancement to Clinical Trials in Patients Bitten by Venomous Snakes. Toxins (Basel) 2022; 14:783. [PMID: 36422958 PMCID: PMC9695340 DOI: 10.3390/toxins14110783] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/26/2022] [Accepted: 11/01/2022] [Indexed: 11/16/2022] Open
Abstract
The availability of effective, reliably accessible, and affordable treatments for snakebite envenoming is a critical and long unmet medical need. Recently, small, synthetic toxin-specific inhibitors with oral bioavailability used in conjunction with antivenom have been identified as having the potential to greatly improve outcomes after snakebite. Varespladib, a small, synthetic molecule that broadly and potently inhibits secreted phospholipase A2 (sPLA2s) venom toxins has renewed interest in this class of inhibitors due to its potential utility in the treatment of snakebite envenoming. The development of varespladib and its oral dosage form, varespladib-methyl, has been accelerated by previous clinical development campaigns to treat non-envenoming conditions related to ulcerative colitis, rheumatoid arthritis, asthma, sepsis, and acute coronary syndrome. To date, twenty-nine clinical studies evaluating the safety, pharmacokinetics (PK), and efficacy of varespladib for non-snakebite envenoming conditions have been completed in more than 4600 human subjects, and the drugs were generally well-tolerated and considered safe for use in humans. Since 2016, more than 30 publications describing the structure, function, and efficacy of varespladib have directly addressed its potential for the treatment of snakebite. This review summarizes preclinical findings and outlines the scientific support, the potential limitations, and the next steps in the development of varespladib's use as a snakebite treatment, which is now in Phase 2 human clinical trials in the United States and India.
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Affiliation(s)
- Matthew R. Lewin
- Division of Research, Ophirex, Inc., Corte Madera, CA 94925, USA
- Center for Exploration and Travel Health, California Academy of Sciences, San Francisco, CA 94118, USA
| | | | - Isabel A. Matteo
- Center for Exploration and Travel Health, California Academy of Sciences, San Francisco, CA 94118, USA
| | | | - Sunita Rao
- Division of Research, Ophirex, Inc., Corte Madera, CA 94925, USA
| | - Bryan G. Fry
- Venom Evolution Lab, School of Biological Science, University of Queensland, St. Lucia, QLD 4072, Australia
| | - Philip E. Bickler
- Center for Exploration and Travel Health, California Academy of Sciences, San Francisco, CA 94118, USA
- Department of Anesthesia and Perioperative Care, University of California San Francisco School of Medicine, San Francisco, CA 94143, USA
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Scott KF, Mann TJ, Fatima S, Sajinovic M, Razdan A, Kim RR, Cooper A, Roohullah A, Bryant KJ, Gamage KK, Harman DG, Vafaee F, Graham GG, Church WB, Russell PJ, Dong Q, de Souza P. Human Group IIA Phospholipase A 2-Three Decades on from Its Discovery. Molecules 2021; 26:molecules26237267. [PMID: 34885848 PMCID: PMC8658914 DOI: 10.3390/molecules26237267] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 11/21/2021] [Accepted: 11/22/2021] [Indexed: 12/13/2022] Open
Abstract
Phospholipase A2 (PLA2) enzymes were first recognized as an enzyme activity class in 1961. The secreted (sPLA2) enzymes were the first of the five major classes of human PLA2s to be identified and now number nine catalytically-active structurally homologous proteins. The best-studied of these, group IIA sPLA2, has a clear role in the physiological response to infection and minor injury and acts as an amplifier of pathological inflammation. The enzyme has been a target for anti-inflammatory drug development in multiple disorders where chronic inflammation is a driver of pathology since its cloning in 1989. Despite intensive effort, no clinically approved medicines targeting the enzyme activity have yet been developed. This review catalogues the major discoveries in the human group IIA sPLA2 field, focusing on features of enzyme function that may explain this lack of success and discusses future research that may assist in realizing the potential benefit of targeting this enzyme. Functionally-selective inhibitors together with isoform-selective inhibitors are necessary to limit the apparent toxicity of previous drugs. There is also a need to define the relevance of the catalytic function of hGIIA to human inflammatory pathology relative to its recently-discovered catalysis-independent function.
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Affiliation(s)
- Kieran F. Scott
- School of Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia; (T.J.M.); (S.F.); (A.C.); (A.R.); (P.d.S.)
- Ingham Institute of Applied Medical Research, Liverpool, NSW 2170, Australia; (M.S.); (A.R.)
- Correspondence: ; Tel.: +61-2-8738-9026
| | - Timothy J. Mann
- School of Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia; (T.J.M.); (S.F.); (A.C.); (A.R.); (P.d.S.)
- Ingham Institute of Applied Medical Research, Liverpool, NSW 2170, Australia; (M.S.); (A.R.)
| | - Shadma Fatima
- School of Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia; (T.J.M.); (S.F.); (A.C.); (A.R.); (P.d.S.)
- Ingham Institute of Applied Medical Research, Liverpool, NSW 2170, Australia; (M.S.); (A.R.)
- School of Biotechnology and Biological Sciences, University of New South Wales (UNSW Sydney), Sydney, NSW 2052, Australia;
| | - Mila Sajinovic
- Ingham Institute of Applied Medical Research, Liverpool, NSW 2170, Australia; (M.S.); (A.R.)
| | - Anshuli Razdan
- Ingham Institute of Applied Medical Research, Liverpool, NSW 2170, Australia; (M.S.); (A.R.)
| | - Ryung Rae Kim
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2006, Australia; (R.R.K.); (W.B.C.)
| | - Adam Cooper
- School of Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia; (T.J.M.); (S.F.); (A.C.); (A.R.); (P.d.S.)
- Ingham Institute of Applied Medical Research, Liverpool, NSW 2170, Australia; (M.S.); (A.R.)
- Liverpool Cancer Therapy Centre, Liverpool Hospital, Liverpool, NSW 2170, Australia
| | - Aflah Roohullah
- School of Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia; (T.J.M.); (S.F.); (A.C.); (A.R.); (P.d.S.)
- Ingham Institute of Applied Medical Research, Liverpool, NSW 2170, Australia; (M.S.); (A.R.)
- Liverpool Cancer Therapy Centre, Liverpool Hospital, Liverpool, NSW 2170, Australia
| | - Katherine J. Bryant
- School of Photovoltaic and Renewable Energy Engineering, UNSW Sydney, Sydney, NSW 2052, Australia;
| | - Kasuni K. Gamage
- School of Science, Western Sydney University, Campbelltown, NSW 2560, Australia; (K.K.G.); (D.G.H.)
| | - David G. Harman
- School of Science, Western Sydney University, Campbelltown, NSW 2560, Australia; (K.K.G.); (D.G.H.)
| | - Fatemeh Vafaee
- School of Biotechnology and Biological Sciences, University of New South Wales (UNSW Sydney), Sydney, NSW 2052, Australia;
- UNSW Data Science Hub, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Garry G. Graham
- Department of Clinical Pharmacology, St Vincent’s Hospital Sydney, Darlinghurst, NSW 2010, Australia;
- School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia
| | - W. Bret Church
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2006, Australia; (R.R.K.); (W.B.C.)
| | - Pamela J. Russell
- Australian Prostate Cancer Research Centre—QUT, Brisbane, QLD 4102, Australia;
| | - Qihan Dong
- Chinese Medicine Anti-Cancer Evaluation Program, Greg Brown Laboratory, Central Clinical School and Charles Perkins Centre, The University of Sydney, Sydney, NSW 2006, Australia;
| | - Paul de Souza
- School of Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia; (T.J.M.); (S.F.); (A.C.); (A.R.); (P.d.S.)
- Ingham Institute of Applied Medical Research, Liverpool, NSW 2170, Australia; (M.S.); (A.R.)
- School of Medicine, UNSW Sydney, Sydney, NSW 2052, Australia
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Kim RR, Chen Z, J. Mann T, Bastard K, F. Scott K, Church WB. Structural and Functional Aspects of Targeting the Secreted Human Group IIA Phospholipase A 2. Molecules 2020; 25:molecules25194459. [PMID: 32998383 PMCID: PMC7583969 DOI: 10.3390/molecules25194459] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 09/20/2020] [Accepted: 09/25/2020] [Indexed: 12/11/2022] Open
Abstract
Human group IIA secretory phospholipase A2 (hGIIA) promotes the proliferation of cancer cells, making it a compelling therapeutic target, but it is also significant in other inflammatory conditions. Consequently, suitable inhibitors of hGIIA have always been sought. The activation of phospholipases A2 and the catalysis of glycerophospholipid substrates generally leads to the release of fatty acids such as arachidonic acid (AA) and lysophospholipid, which are then converted to mediator compounds, including prostaglandins, leukotrienes, and the platelet-activating factor. However, this ability of hGIIA to provide AA is not a complete explanation of its biological role in inflammation, as it has now been shown that it also exerts proinflammatory effects by a catalysis-independent mechanism. This mechanism is likely to be highly dependent on key specific molecular interactions, and the full mechanistic descriptions of this remain elusive. The current candidates for the protein partners that may mediate this catalysis-independent mechanism are also introduced in this review. A key discovery has been that selective inhibition of the catalysis-independent activity of hGIIA is achieved with cyclised derivatives of a pentapeptide, FLSYK, derived from the primary sequence of hGIIA. The effects of hGIIA on cell function appear to vary depending on the pathology studied, and so its mechanism of action is complex and context-dependent. This review is comprehensive and covers the most recent developments in the understanding of the many facets of hGIIA function and inhibition and the insight they provide into their clinical application for disease treatment. A cyclic analogue of FLSYK, c2, the most potent analogue known, has now been taken into clinical trials targeting advanced prostate cancer.
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Affiliation(s)
- Ryung Rae Kim
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2006, Australia; (R.R.K.); (Z.C.); (K.B.)
| | - Zheng Chen
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2006, Australia; (R.R.K.); (Z.C.); (K.B.)
| | - Timothy J. Mann
- School of Medicine, Western Sydney University, Centre for Oncology, Education and Research Translation and The Ingham Institute, Liverpool, NSW 2170, Australia;
| | - Karine Bastard
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2006, Australia; (R.R.K.); (Z.C.); (K.B.)
| | - Kieran F. Scott
- School of Medicine, Western Sydney University, Centre for Oncology, Education and Research Translation and The Ingham Institute, Liverpool, NSW 2170, Australia;
- Correspondence: (K.F.S.); (W.B.C.); Tel.: +61-2-8738-9026 (K.F.S.); +61-2-9036-6569 (W.B.C.)
| | - W. Bret Church
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2006, Australia; (R.R.K.); (Z.C.); (K.B.)
- Correspondence: (K.F.S.); (W.B.C.); Tel.: +61-2-8738-9026 (K.F.S.); +61-2-9036-6569 (W.B.C.)
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A Potential Role of Phospholipase 2 Group IIA (PLA 2-IIA) in P. gingivalis-Induced Oral Dysbiosis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019. [PMID: 31732936 DOI: 10.1007/978-3-030-28524-1_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/29/2023]
Abstract
Porphyromonas gingivalis is an oral pathogen with the ability to induce oral dysbiosis and periodontal disease. Nevertheless, the mechanisms by which P. gingivalis could abrogate the host-microbe symbiotic relationship leading to oral dysbiosis remain unclear. We have recently demonstrated that P. gingivalis specifically increased the antimicrobial properties of oral epithelial cells, through a strong induction of the expression of PLA2-IIA in a mechanism that involves activation of the Notch-1 receptor. Moreover, gingival expression of PLA2-IIA was significantly increased during initiation and progression of periodontal disease in non-human primates and interestingly, those PLA2-IIA expression changes were concurrent with oral dysbiosis. In this chapter, we present an innovative hypothesis of a potential mechanism involved in P. gingivalis-induced oral dysbiosis and inflammation based on our previous observations and a robust body of literature that supports the antimicrobial and proinflammatory properties of PLA2-IIA as well as its role in other chronic inflammatory diseases.
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Duchez AC, Boudreau LH, Naika GS, Rousseau M, Cloutier N, Levesque T, Gelb MH, Boilard E. Respective contribution of cytosolic phospholipase A2α and secreted phospholipase A 2 IIA to inflammation and eicosanoid production in arthritis. Prostaglandins Other Lipid Mediat 2019; 143:106340. [PMID: 31129176 DOI: 10.1016/j.prostaglandins.2019.106340] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 05/11/2019] [Accepted: 05/15/2019] [Indexed: 12/30/2022]
Abstract
Phospholipase A2s (PLA2) play a key role in generation of eicosanoids. Cytosolic PLA2α (cPLA2α) is constitutively expressed in most cells, whereas IIA secreted PLA2 (sPLA2-IIA) is induced during inflammation and is present at high levels in the synovial fluid of rheumatoid arthritis patients. In mice, both cPLA2α and sPLA2-IIA have been implicated in autoimmune arthritis; however, the respective contribution of these two enzymes to the pathogenesis and production of eicosanoids is unknown. We evaluated the respective role of cPLA2α and sPLA2-IIA with regard to arthritis and eicosanoid profile in an in vivo model of arthritis. While arthritis was most severe in mice expressing both enzymes, it was abolished when both cPLA2α and sPLA2-IIA were lacking. cPLA2α played a dominant role in the severity of arthritis, although sPLA2-IIA sufficed to significantly contribute to the disease. Several eicosanoids were modulated during the course of arthritis and numerous species involved sPLA2-IIA expression. This study confirms the critical role of PLA2s in arthritis and unveils the distinct contribution of cPLA2α and sPLA2-IIA to the eicosanoid profile in arthritis.
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Affiliation(s)
- Anne-Claire Duchez
- Centre de Recherche du Centre Hospitalier Universitaire de Québec, Faculté de Médecine de l'Université Laval, Département de microbiologie et immunologie, Québec, QC, G1V 4G2, Canada
| | - Luc H Boudreau
- Centre de Recherche du Centre Hospitalier Universitaire de Québec, Faculté de Médecine de l'Université Laval, Département de microbiologie et immunologie, Québec, QC, G1V 4G2, Canada; Department of Chemistry and Biochemistry, Université de Moncton, Moncton, E1A 3E9, Canada
| | - Gajendra S Naika
- Department of Chemistry, University of Washington, Seattle, WA, 98195, USA
| | - Matthieu Rousseau
- Centre de Recherche du Centre Hospitalier Universitaire de Québec, Faculté de Médecine de l'Université Laval, Département de microbiologie et immunologie, Québec, QC, G1V 4G2, Canada
| | - Nathalie Cloutier
- Centre de Recherche du Centre Hospitalier Universitaire de Québec, Faculté de Médecine de l'Université Laval, Département de microbiologie et immunologie, Québec, QC, G1V 4G2, Canada
| | - Tania Levesque
- Centre de Recherche du Centre Hospitalier Universitaire de Québec, Faculté de Médecine de l'Université Laval, Département de microbiologie et immunologie, Québec, QC, G1V 4G2, Canada
| | - Michael H Gelb
- Department of Chemistry, University of Washington, Seattle, WA, 98195, USA
| | - Eric Boilard
- Centre de Recherche du Centre Hospitalier Universitaire de Québec, Faculté de Médecine de l'Université Laval, Département de microbiologie et immunologie, Québec, QC, G1V 4G2, Canada; Canadian National Transplantation Research Program, Edmonton, Alberta, Canada.
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6
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Shivashankar S, Murali A, Sangeetha M. Molecular interaction of phytochemicals with snake venom: Phytochemicals of Andrographis paniculata inhibits phospholipase A2 of Russell's viper (Daboia russelli). BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2019. [DOI: 10.1016/j.bcab.2019.101058] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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7
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Dore E, Boilard E. Roles of secreted phospholipase A 2 group IIA in inflammation and host defense. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1864:789-802. [PMID: 30905346 DOI: 10.1016/j.bbalip.2018.08.017] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 08/29/2018] [Accepted: 08/30/2018] [Indexed: 01/08/2023]
Abstract
Among all members of the secreted phospholipase A2 (sPLA2) family, group IIA sPLA2 (sPLA2-IIA) is possibly the most studied enzyme. Since its discovery, many names have been associated with sPLA2-IIA, such as "non-pancreatic", "synovial", "platelet-type", "inflammatory", and "bactericidal" sPLA2. Whereas the different designations indicate comprehensive functions or sources proposed for this enzyme, the identification of the precise roles of sPLA2-IIA has remained a challenge. This can be attributed to: the expression of the enzyme by various cells of different lineages, its limited activity towards the membranes of immune cells despite its expression following common inflammatory stimuli, its ability to interact with certain proteins independently of its catalytic activity, and its absence from multiple commonly used mouse models. Nevertheless, elevated levels of the enzyme during inflammatory processes and associated consistent release of arachidonic acid from the membrane of extracellular vesicles suggest that sPLA2-IIA may contribute to inflammation by using endogenous substrates in the extracellular milieu. Moreover, the remarkable potency of sPLA2-IIA towards bacterial membranes and its induced expression during the course of infections point to a role for this enzyme in the defense of the host against invading pathogens. In this review, we present current knowledge related to mammalian sPLA2-IIA and its roles in sterile inflammation and host defense.
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Affiliation(s)
- Etienne Dore
- Centre de Recherche du CHU de Québec, Université Laval, Department of Infectious Diseases and Immunity, Québec City, QC, Canada
| | - Eric Boilard
- Centre de Recherche du CHU de Québec, Université Laval, Department of Infectious Diseases and Immunity, Québec City, QC, Canada; Canadian National Transplantation Research Program, Edmonton, AB, Canada.
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Caprio V, Badimon L, Di Napoli M, Fang WH, Ferris GR, Guo B, Iemma RS, Liu D, Zeinolabediny Y, Slevin M. pCRP-mCRP Dissociation Mechanisms as Potential Targets for the Development of Small-Molecule Anti-Inflammatory Chemotherapeutics. Front Immunol 2018; 9:1089. [PMID: 29892284 PMCID: PMC5985513 DOI: 10.3389/fimmu.2018.01089] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 05/01/2018] [Indexed: 12/29/2022] Open
Abstract
Circulating C-reactive protein (CRP) is a key acute-phase protein and one of the main clinical biomarkers for inflammation and infection. CRP is an important upstream mediator of inflammation and is associated with the onset of a number of important disease states including cardiovascular disease and neurodegenerative disorders such as Alzheimer’s disease. This pentraxin exerts pro-inflammatory properties via dissociation of the pentamer (pCRP) to a monomeric form (mCRP). This dissociation is induced by binding of pCRP to cell surface phosphocholine residues exposed by the action of phospholipase A2 (PLA2). Given the association of CRP with the onset of a range of serious disease states this CRP dissociation process is a tempting drug target for the development of novel small-molecule therapeutics. This review will discuss potential targets for chemotherapeutic intervention elucidated during studies of CRP-mediated inflammation and provide an up-to-date summary of the development of small molecules, not only targeted directly at inhibiting conversion of pCRP to mCRP, but also those developed for activity against PLA2, given the key role of this enzyme in the activation of CRP.
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Affiliation(s)
- Vittorio Caprio
- Faculty of Science and Engineering, School of Healthcare Science, Manchester Metropolitan University, Manchester, United Kingdom
| | - Lina Badimon
- Hospital de la Santa Creu I Sant Pau, IIB Sant Pau, Barcelona, Spain
| | - Mario Di Napoli
- Neurological Service, Ospedale San Camillo de Lellis, Rieti, Italy
| | - Wen-Hui Fang
- Faculty of Science and Engineering, School of Healthcare Science, Manchester Metropolitan University, Manchester, United Kingdom
| | - Glenn R Ferris
- Faculty of Science and Engineering, School of Healthcare Science, Manchester Metropolitan University, Manchester, United Kingdom
| | - Baoqiang Guo
- Faculty of Science and Engineering, School of Healthcare Science, Manchester Metropolitan University, Manchester, United Kingdom.,Institute of Dementia and Neurological Aging, Weifang Medical University, Weifang, China
| | - Rocco S Iemma
- Faculty of Science and Engineering, School of Healthcare Science, Manchester Metropolitan University, Manchester, United Kingdom
| | - Donghui Liu
- Faculty of Science and Engineering, School of Healthcare Science, Manchester Metropolitan University, Manchester, United Kingdom.,University of Medicine and Pharmacy, Targu Mures, Romania
| | - Yasmin Zeinolabediny
- Faculty of Science and Engineering, School of Healthcare Science, Manchester Metropolitan University, Manchester, United Kingdom.,University of Medicine and Pharmacy, Targu Mures, Romania
| | - Mark Slevin
- Faculty of Science and Engineering, School of Healthcare Science, Manchester Metropolitan University, Manchester, United Kingdom.,Hospital de la Santa Creu I Sant Pau, IIB Sant Pau, Barcelona, Spain.,Institute of Dementia and Neurological Aging, Weifang Medical University, Weifang, China.,University of Medicine and Pharmacy, Targu Mures, Romania
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In silico investigation of the molecular effects caused by R123H variant in secretory phospholipase A2-IIA associated with ARDS. J Mol Graph Model 2018. [PMID: 29529495 DOI: 10.1016/j.jmgm.2018.02.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Phospholipase A2-IIA catalyzes the hydrolysis of the sn-2 ester of glycerophospholipids. A rare c.428G > A (p.Arg143His) variant in PLA2G2A gene was found in two infants affected by acute respiratory distress syndrome (ARDS) by whole coding region and exon/intron boundaries sequencing. To obtain insights into the possible molecular effects of the rare R123H mutation in secretory PLA2-IIA (sPLA2-IIA), molecular modelling, molecular dynamics (MD) using principal component analysis (PCA) and continuum electrostatic calculations were conducted on the crystal structure of the wild type protein and on a generated model structure of the R123H mutant. Analysis of MD trajectories indicate that the overall stability of the protein is not affected by this mutation but nevertheless the catalytically crucial H-bond between Tyr51 and Asp91 as well as main electrostatic interactions in the region close to the mutation site are altered. PCA results indicate that the R123H replacement alter the internal molecular motions of the enzyme and that collective motions are increased. Electrostatic surface potential studies suggest that after mutation the interfacial binding to anionic phospholipid membranes and anionic proteins may be changed. The strengthening of electrostatic interactions may be propagated into the active site region thus potentially affecting the substrate recognition and enzymatic activity. Our findings provide the basis for further investigation and advances our understanding of the effects of mutations on sPLA2 structure and function.
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Seroussi E, Klompus S, Silanikove M, Krifucks O, Shapiro F, Gertler A, Leitner G. Nonbactericidal secreted phospholipase A2s are potential anti-inflammatory factors in the mammary gland. Immunogenetics 2013; 65:861-71. [PMID: 24091988 DOI: 10.1007/s00251-013-0738-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 09/20/2013] [Indexed: 12/17/2022]
Abstract
The recent burst of duplication and divergence of the bovine PLA2G2D genes is considered typical of immune response genes, and it was recently shown that PLA2G2D is abundantly expressed in mouse leukocytes and acts as an immunosuppressive phospholipase. Analysis of 1,143 Holstein bulls indicated that the four common haplotypes spanning PLA2G2D display copy number variation ranging from 1 to 4 per haploid genome. Association of the fourth haplotype with negative total merit remained significant (P < 0.002) when corrected for population relatedness. We compared the lipase and bactericidal activities of bovine pancreatic PLA2G1B with human PLA2G2A and G2D and bovine PLA2G2D1 and G2D4 proteins, which had been subcloned, expressed, and refolded by us, and the impact of point mutations in the calcium binding site was investigated. All tested phospholipases were ineffective bactericides of Escherichia coli isolated from bovine mastitis. However, in lactating mice treated with E. coli or lipopolysaccharide (LPS), intramammary injection of bovine PLA2G1B relieved visual and histological inflammation and reduced blood levels of infiltrating lactose. Further studies are warranted to determine whether the observed anti-inflammatory effect involves competitive binding of the receptor Pla2r1 which may mimic the LPS resistance effect in Pla2r1-deficient mice.
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Affiliation(s)
- Eyal Seroussi
- Institute of Animal Science, ARO, The Volcani Center, P.O. Box 6, Beit Dagan, 50250, Israel,
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Deng Q, Cao B, Lai L. Receptor Mapping by Comparative Molecular Field Analysis of Phospholipase A2Inhibitors. J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.199500098] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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12
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Lee LK, Bryant KJ, Bouveret R, Lei PW, Duff AP, Harrop SJ, Huang EP, Harvey RP, Gelb MH, Gray PP, Curmi PM, Cunningham AM, Church WB, Scott KF. Selective inhibition of human group IIA-secreted phospholipase A2 (hGIIA) signaling reveals arachidonic acid metabolism is associated with colocalization of hGIIA to vimentin in rheumatoid synoviocytes. J Biol Chem 2013; 288:15269-79. [PMID: 23482564 PMCID: PMC3663547 DOI: 10.1074/jbc.m112.397893] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Revised: 03/06/2013] [Indexed: 11/06/2022] Open
Abstract
Human group IIA secreted phospholipase A2 (hGIIA) promotes tumor growth and inflammation and can act independently of its well described catalytic lipase activity via an alternative poorly understood signaling pathway. With six chemically diverse inhibitors we show that it is possible to selectively inhibit hGIIA signaling over catalysis, and x-ray crystal structures illustrate that signaling involves a pharmacologically distinct surface to the catalytic site. We demonstrate in rheumatoid fibroblast-like synoviocytes that non-catalytic signaling is associated with rapid internalization of the enzyme and colocalization with vimentin. Trafficking of exogenous hGIIA was monitored with immunofluorescence studies, which revealed that vimentin localization is disrupted by inhibitors of signaling that belong to a rare class of small molecule inhibitors that modulate protein-protein interactions. This study provides structural and pharmacological evidence for an association between vimentin, hGIIA, and arachidonic acid metabolism in synovial inflammation, avenues for selective interrogation of hGIIA signaling, and new strategies for therapeutic hGIIA inhibitor design.
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Affiliation(s)
- Lawrence K. Lee
- From the Faculty of Pharmacy, The University of Sydney, Sydney, New South Wales 2006, Australia
- School of Medical Sciences
| | | | - Romaric Bouveret
- St. Vincent's Hospital Clinical School, and
- Victor Chang Cardiac Research Institute, Sydney, New South Wales 2010, Australia
| | | | - Anthony P. Duff
- The Australian Nuclear Science and Technology Organisation, Sydney, New South Wales 2234, Australia
| | - Stephen J. Harrop
- School of Physics, Faculty of Science, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | | | - Richard P. Harvey
- St. Vincent's Hospital Clinical School, and
- Victor Chang Cardiac Research Institute, Sydney, New South Wales 2010, Australia
| | - Michael H. Gelb
- the Departments of Chemistry and Biochemistry, University of Washington, Seattle, Washington 98195
| | | | - Paul M. Curmi
- School of Physics, Faculty of Science, The University of New South Wales, Sydney, New South Wales 2052, Australia
- Centre for Applied Medical Research, St. Vincent's Hospital, Sydney, New South Wales 2010, Australia, and
| | | | - W. Bret Church
- From the Faculty of Pharmacy, The University of Sydney, Sydney, New South Wales 2006, Australia
- School of Medical Sciences
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Iyer A, Lim J, Poudyal H, Reid RC, Suen JY, Webster J, Prins JB, Whitehead JP, Fairlie DP, Brown L. An inhibitor of phospholipase A2 group IIA modulates adipocyte signaling and protects against diet-induced metabolic syndrome in rats. Diabetes 2012; 61:2320-9. [PMID: 22923652 PMCID: PMC3425408 DOI: 10.2337/db11-1179] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Obesity, type 2 diabetes, and cardiovascular disease correlate with infiltration to adipose tissue of different immune cells, with uncertain influences on metabolism. Rats were fed a diet high in carbohydrates and saturated fats to develop diet-induced obesity over 16 weeks. This nutritional overload caused overexpression and secretion of phospholipase A(2) group IIA (pla2g2a) from immune cells in adipose tissue rather than adipocytes, whereas expression of adipose-specific phospholipase A(2) (pla2g16) was unchanged. These immune cells produce prostaglandin E(2) (PGE(2)), which influences adipocyte signaling. We found that a selective inhibitor of human pla2g2a (5-(4-benzyloxyphenyl)-(4S)-(phenyl-heptanoylamino)-pentanoic acid [KH064]) attenuated secretion of PGE(2) from human immune cells stimulated with the fatty acid, palmitic acid, or with lipopolysaccharide. Oral administration of KH064 (5 mg/kg/day) to rats fed the high-carbohydrate, high-fat diet prevented the overexpression of pla2g2a and the increased macrophage infiltration and elevated PGE(2) concentrations in adipose tissue. The treatment also attenuated visceral adiposity and reversed most characteristics of metabolic syndrome, producing marked improvements in insulin sensitivity, glucose intolerance, and cardiovascular abnormalities. We suggest that pla2g2a may have a causal relationship with chronic adiposity and metabolic syndrome and that its inhibition in vivo may be a valuable new approach to treat obesity, type 2 diabetes, and metabolic dysfunction in humans.
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Affiliation(s)
- Abishek Iyer
- School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Junxian Lim
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Hemant Poudyal
- School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Robert C. Reid
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Jacky Y. Suen
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Julie Webster
- Mater Medical Research Institute (MMRI), South Brisbane, Queensland, Australia
| | - Johannes B. Prins
- Mater Medical Research Institute (MMRI), South Brisbane, Queensland, Australia
| | | | - David P. Fairlie
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
- Corresponding authors: Lindsay Brown, , and David Fairlie,
| | - Lindsay Brown
- School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia
- Department of Biological and Physical Sciences, University of Southern Queensland, Toowoomba, Queensland, Australia
- Corresponding authors: Lindsay Brown, , and David Fairlie,
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Nevalainen TJ, Cardoso JCR, Riikonen PT. Conserved domains and evolution of secreted phospholipases A2. FEBS J 2012; 279:636-49. [DOI: 10.1111/j.1742-4658.2011.08453.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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15
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Perumal Samy R, Gopalakrishnakone P, Chow VTK. Therapeutic application of natural inhibitors against snake venom phospholipase A(2). Bioinformation 2012; 8:48-57. [PMID: 22359435 PMCID: PMC3282276 DOI: 10.6026/97320630008048] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Accepted: 12/17/2011] [Indexed: 02/07/2023] Open
Abstract
Natural inhibitors occupy an important place in the potential to neutralize the toxic effects caused by snake venom proteins and enzymes. It has been well recognized for several years that animal sera, some of the plant and marine extracts are the most potent in neutralizing snake venom phospholipase A(2) (svPLA(2)). The implication of this review to update the latest research work which has been accomplished with svPLA(2) inhibitors from various natural sources like animal, marine organisms presents a compilation of research in this field over the past decade and revisiting the previous research report including those found in plants. In addition to that the bioactive compounds/inhibitor molecules from diverse sources like aristolochic alkaloid, flavonoids and neoflavonoids from plants, hydrocarbones -2, 4 dimethyl hexane, 2 methylnonane, and 2, 6 dimethyl heptane obtained from traditional medicinal plants Tragia involucrata (Euphorbiaceae) member of natural products involved for the inhibitory potential of phospholipase A(2) (PLA(2)) enzymes in vitro and also decrease both oedema induced by snake venom as well as human synovial fluid PLA(2). Besides marine natural products that inhibit PLA(2) are manoalide and its derivatives such as scalaradial and related compounds, pseudopterosins and vidalols, tetracylne from synthetic chemicals etc. There is an overview of the role of PLA(2) in inflammation that provides a rationale for seeking inhibitors of PLA(2) as anti-inflammatory agents. However, more studies should be considered to evaluate antivenom efficiency of sera and other agents against a variety of snake venoms found in various parts of the world. The implications of these new groups of svPLA(2) toxin inhibitors in the context of our current understanding of snake biology as well as in the development of new novel antivenoms therapeutics agents in the efficient treatment of snake envenomations are discussed.
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Affiliation(s)
- Ramar Perumal Samy
- Infectious Disease Programme, Department of Microbiology
- Venom and Toxin Research Programme, Department of Anatomy; Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597
| | - Ponnampalam Gopalakrishnakone
- Venom and Toxin Research Programme, Department of Anatomy; Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597
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Dennis EA, Cao J, Hsu YH, Magrioti V, Kokotos G. Phospholipase A2 enzymes: physical structure, biological function, disease implication, chemical inhibition, and therapeutic intervention. Chem Rev 2011; 111:6130-85. [PMID: 21910409 PMCID: PMC3196595 DOI: 10.1021/cr200085w] [Citation(s) in RCA: 820] [Impact Index Per Article: 63.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Edward A. Dennis
- Department of Chemistry and Biochemistry and Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093-0601
| | - Jian Cao
- Department of Chemistry and Biochemistry and Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093-0601
| | - Yuan-Hao Hsu
- Department of Chemistry and Biochemistry and Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093-0601
| | - Victoria Magrioti
- Laboratory of Organic Chemistry, Department of Chemistry, University of Athens, Panepistimiopolis, Athens 15771, Greece
| | - George Kokotos
- Laboratory of Organic Chemistry, Department of Chemistry, University of Athens, Panepistimiopolis, Athens 15771, Greece
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Active site mutants of human secreted Group IIA Phospholipase A2 lacking hydrolytic activity retain their bactericidal effect. Biochimie 2011; 94:132-6. [PMID: 21986368 DOI: 10.1016/j.biochi.2011.09.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Accepted: 09/29/2011] [Indexed: 11/22/2022]
Abstract
The Human Secreted Group IIA Phospholipase A(2) (hsPLA2GIIA) presents potent bactericidal activity, and is considered to contribute to the acute-phase immune response. Hydrolysis of inner membrane phospholipids is suggested to underlie the bactericidal activity, and we have evaluated this proposal by comparing catalytic activity with bactericidal and liposome membrane damaging effects of the G30S, H48Q and D49K hsPLA2GIIA mutants. All mutants showed severely impaired hydrolytic activities against mixed DOPC:DOPG liposome membranes, however the bactericidal effect against Micrococcus luteus was less affected, with 50% killing at concentrations of 1, 3, 7 and 9 μg/mL for the wild-type, D49K, H48Q and G30S mutants respectively. Furthermore, all proteins showed Ca(2+)-independent damaging activity against liposome membranes demonstrating that in addition to the hydrolysis-dependent membrane damage, the hsPLA2GIIA presents a mechanism for permeabilization of phospholipid bilayers that is independent of catalytic activity, which may play a role in the bactericidal function of the protein.
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Crystal Structure of Crotoxin Reveals Key Residues Involved in the Stability and Toxicity of This Potent Heterodimeric β-Neurotoxin. J Mol Biol 2011; 412:176-91. [DOI: 10.1016/j.jmb.2011.07.027] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Revised: 06/17/2011] [Accepted: 07/14/2011] [Indexed: 11/21/2022]
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Kang TS, Georgieva D, Genov N, Murakami MT, Sinha M, Kumar RP, Kaur P, Kumar S, Dey S, Sharma S, Vrielink A, Betzel C, Takeda S, Arni RK, Singh TP, Kini RM. Enzymatic toxins from snake venom: structural characterization and mechanism of catalysis. FEBS J 2011; 278:4544-76. [PMID: 21470368 DOI: 10.1111/j.1742-4658.2011.08115.x] [Citation(s) in RCA: 189] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Snake venoms are cocktails of enzymes and non-enzymatic proteins used for both the immobilization and digestion of prey. The most common snake venom enzymes include acetylcholinesterases, l-amino acid oxidases, serine proteinases, metalloproteinases and phospholipases A(2) . Higher catalytic efficiency, thermal stability and resistance to proteolysis make these enzymes attractive models for biochemists, enzymologists and structural biologists. Here, we review the structures of these enzymes and describe their structure-based mechanisms of catalysis and inhibition. Some of the enzymes exist as protein complexes in the venom. Thus we also discuss the functional role of non-enzymatic subunits and the pharmacological effects of such protein complexes. The structures of inhibitor-enzyme complexes provide ideal platforms for the design of potent inhibitors which are useful in the development of prototypes and lead compounds with potential therapeutic applications.
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Affiliation(s)
- Tse Siang Kang
- Department of Pharmacy, National University of Singapore, Singapore
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Petronzi C, Filosa R, Peduto A, Monti MC, Margarucci L, Massa A, Ercolino SF, Bizzarro V, Parente L, Riccio R, de Caprariis P. Structure-based design, synthesis and preliminary anti-inflammatory activity of bolinaquinone analogues. Eur J Med Chem 2011; 46:488-96. [DOI: 10.1016/j.ejmech.2010.11.028] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Revised: 11/15/2010] [Accepted: 11/17/2010] [Indexed: 11/29/2022]
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Mouchlis VD, Magrioti V, Barbayianni E, Cermak N, Oslund RC, Mavromoustakos TM, Gelb MH, Kokotos G. Inhibition of secreted phospholipases A₂ by 2-oxoamides based on α-amino acids: Synthesis, in vitro evaluation and molecular docking calculations. Bioorg Med Chem 2010; 19:735-43. [PMID: 21216150 DOI: 10.1016/j.bmc.2010.12.030] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Revised: 12/07/2010] [Accepted: 12/13/2010] [Indexed: 10/18/2022]
Abstract
Group IIA secreted phospholipase A₂ (GIIA sPLA₂) is a member of the mammalian sPLA₂ enzyme family and is associated with various inflammatory conditions. In this study, the synthesis of 2-oxoamides based on α-amino acids and the in vitro evaluation against three secreted sPLA₂s (GIIA, GV and GX) are described. The long chain 2-oxoamide GK126 based on the amino acid (S)-leucine displayed inhibition of human and mouse GIIA sPLA₂s (IC₅₀ 300nM and 180nM, respectively). It also inhibited human GV sPLA₂ with similar potency, while it did not inhibit human GX sPLA₂. The elucidation of the stereoelectronic characteristics that affect the in vitro activity of these compounds was achieved by using a combination of simulated annealing to sample low-energy conformations before the docking procedure, and molecular docking calculations.
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Mouchlis VD, Mavromoustakos TM, Kokotos G. Molecular Docking and 3D-QSAR CoMFA Studies on Indole Inhibitors of GIIA Secreted Phospholipase A2. J Chem Inf Model 2010; 50:1589-601. [PMID: 20795712 DOI: 10.1021/ci100217k] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Varnavas D. Mouchlis
- Laboratory of Organic Chemistry, Department of Chemistry, University of Athens, Panepistimiopolis, Athens 15771, Greece
| | - Thomas M. Mavromoustakos
- Laboratory of Organic Chemistry, Department of Chemistry, University of Athens, Panepistimiopolis, Athens 15771, Greece
| | - George Kokotos
- Laboratory of Organic Chemistry, Department of Chemistry, University of Athens, Panepistimiopolis, Athens 15771, Greece
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24
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Goracci G, Ferrini M, Nardicchi V. Low Molecular Weight Phospholipases A2 in Mammalian Brain and Neural Cells: Roles in Functions and Dysfunctions. Mol Neurobiol 2010; 41:274-89. [DOI: 10.1007/s12035-010-8108-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2010] [Accepted: 02/11/2010] [Indexed: 12/14/2022]
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25
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Mouchlis VD, Mavromoustakos TM, Kokotos G. Design of new secreted phospholipase A2 inhibitors based on docking calculations by modifying the pharmacophore segments of the FPL67047XX inhibitor. J Comput Aided Mol Des 2010; 24:107-15. [DOI: 10.1007/s10822-010-9319-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2009] [Accepted: 01/21/2010] [Indexed: 10/19/2022]
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26
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Ompraba G, Velmurugan D, Louis PA, Rafi ZA. Molecular Modeling of the Additional Inhibitor Site Located in Secretory Phospholipase A2. J Biomol Struct Dyn 2010; 27:489-500. [DOI: 10.1080/07391102.2010.10507333] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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27
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Catalytic and non-catalytic functions of human IIA phospholipase A2. Trends Biochem Sci 2009; 35:28-35. [PMID: 19818633 DOI: 10.1016/j.tibs.2009.08.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2009] [Revised: 07/31/2009] [Accepted: 08/04/2009] [Indexed: 11/30/2022]
Abstract
Group IIA phospholipase A2 (PLA2) is a low-molecular-mass secreted PLA2 enzyme that has been identified as an acute phase protein with a role in the inflammatory response to infection and trauma. The protein is possibly unique in being highly cationic and having a global distribution of surface arginine and lysine residues. This structure supports two functions of the protein. (1) An anti-bacterial role where the enzyme is targeted to the anionic cell membrane of Gram-positive bacteria and phospholipid hydrolysis assists in bacterial killing. (2) A proposed non-catalytic role in which the protein forms supramolecular aggregates with anionic phospholipid vesicles or debris. These aggregates are then internalized via interactions with cell surface heparin sulphate proteoglycans and macropinocytosis for disposal by macrophages.
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28
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Cancer-relevant biochemical targets of cytotoxic Lonchocarpus flavonoids: A molecular docking analysis. J Mol Model 2009; 16:311-26. [DOI: 10.1007/s00894-009-0547-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2009] [Accepted: 06/11/2009] [Indexed: 11/25/2022]
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29
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Guy JE, Ståhl U, Lindqvist Y. Crystal structure of a class XIB phospholipase A2 (PLA2): rice (oryza sativa) isoform-2 pla2 and an octanoate complex. J Biol Chem 2009; 284:19371-9. [PMID: 19457861 DOI: 10.1074/jbc.m109.008466] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Phospholipase A(2) catalyzes the specific hydrolysis of the sn-2 acyl bond of various glycerophospholipids, producing fatty acids and lysophospholipids. Phospholipase A(2)s (PLA(2)s) constitute a large superfamily of enzymes whose products are important for a multitude of signal transduction processes, lipid mediator release, lipid metabolism, development, plant stress responses, and host defense. The crystal structure of rice (Oryza sativa) isoform 2 phospholipase A(2) has been determined to 2.0 A resolution using sulfur SAD phasing, and shows that the class XIb phospholipases have a unique structure compared with other secreted PLA(2)s. The N-terminal half of the chain contains mainly loop structure, including the conserved Ca(2+)-binding loop, but starts with a short 3(10)-helix and also includes two short anti-parallel beta-strands. The C-terminal half is folded into three anti-parallel alpha-helices, of which the two first are also present in other secreted PLA(2)s and contain the conserved catalytic histidine and calcium liganding aspartate residues. The structure is stabilized by six disulfide bonds. The water structure around the calcium ion binding site suggests the involvement of a second water molecule in the mechanism for hydrolysis, the water-assisted calcium-coordinate oxyanion mechanism. The octanoate molecule in the complex structure is bound in a hydrophobic pocket, which extends to the likely membrane interface and is proposed to model the binding of the product fatty acid. Due to the differences in structure, the suggested surface for binding to the membrane has a different morphology in the rice PLA(2) compared with other phospholipases.
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Affiliation(s)
- Jodie E Guy
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm S-17177, Sweden
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Singh RK, Singh N, Jabeen T, Sharma S, Dey S, Singh TP. Crystal structure of the complex of group I PLA2with a group II-specific peptide Leu-Ala-Ile-Tyr-Ser (LAIYS) at 2.6 Å resolution. J Drug Target 2008; 13:367-74. [PMID: 16278156 DOI: 10.1080/10611860500254450] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Phospholipases A(2)s (PLA(2)s) are widely distributed in mammals and snake venoms. They catalyze the production of arachidonic acid from membrane phospholipids leading to the bioynthesis of pro-inflammatory eicosanoids. A peptide Leu-Ala-Ile-Tyr-Ser (LAIYS) was designed and synthesized as a specific inhibitor of PLA(2). It was shown earlier that the peptide bound to group II PLA(2) specifically and had a dissociation constant (K(d)) of 8.8 x 10(-9) M. In the present studies for the binding of LAIYS with a group I PLA(2) from Naja naja sagittifera using surface plasmon resonance the dissociation constant was found to be 4.5 x 10(-5) M which is considerably lower than the value found for the group II PLA(2). In order to determine the details of binding at the molecular level, a group I PLA(2) from the venom of Naja naja sagittifera was crystallized with peptide LAIYS. The crystal structure showed the presence of LAIYS at the substrate-binding site but has fewer interactions than those observed with group II PLA(2) from Daboia russelli pulchella. The observed difference in the binding affinity is caused primarily due to poor fitting of the peptide LAIYS in the binding site of group I PLA(2). Apparently, the location of Trp 19 in group I PLA(2) is not favourable for the binding of LAIYS. The two complexes also differ drastically in the formation of intermolecular interactions. In the present structure, the side chain of Ser (P) interacts with His 48 and Asp 49 while in the complex with group II PLA(2) it was Tyr (P) OH that formed the corresponding interactions. Tyr (P) in group I PLA(2) is the main contributor of the hydrophobic interactions whereas in the complex of LAIYS with group II PLA(2) it was the peptide segment Leu-Ala-Ile that produced the bulk of hydrophobic forces. The structures further showed that the peptide LAIYS was fully inside the substrate-binding region of the group II PLA(2) while a significant portion of the peptide LAIYS was hanging outside the surface of the group I PLA(2). The buried area in the complex with group II PLA(2) was 811 A(2) whereas, the corresponding area in group I PLA(2) was 449 A(2). This shows that the peptide LAIYS is very compatible with the substrate-binding site of group II PLA(2) and rather poorly fits into the substrate-binding site of group I PLA(2). This indicates that a highly specific ligand for one form of PLA(2) may be a poor partner for another form of enzyme.
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Affiliation(s)
- Rajendra K Singh
- All India Institute of Medical Sciences, Department of Biophysics, New Delhi, India
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Angel J, Berenbaum F, Denmat C, Nevalainen T, Masliah J, Fournier C. Interleukin-1-Induced Prostaglandin E2 Biosynthesis in Human Synovial Cells Involves the Activation of Cytosolic Phospholipase A2 and Cyclooxygenase-2. ACTA ACUST UNITED AC 2008. [DOI: 10.1111/j.1432-1033.1994.0t125.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Thireou T, Atlamazoglou V, Levakis M, Eliopoulos E, Hountas A, Tsoucaris G, Bethanis K. CrystTwiV: a webserver for automated phase extension and refinement in X-ray crystallography. Nucleic Acids Res 2007; 35:W718-22. [PMID: 17488848 PMCID: PMC1933117 DOI: 10.1093/nar/gkm225] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
An important stage in macromolecular crystallography is that of phase extension and refinement when initial phase estimates are available from isomorphous replacement or anomalous scattering or other methods. For this purpose, an alternative method called the twin variables (TwiV) method has been proposed. The algorithm is based on alternately transferring the phase information between the twin variable sets. The phase extension and refinement is evaluated with the crystallographic symmetry test by deliberately sacrificing the space-group symmetry in the starting set, then using its re-appearance as a criterion for correctness. Here we present a software program (CrysTwiV) that runs on the web (freely available at: http://btweb.aua.gr/crystwiv/) implementing the above-mentioned method.
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Affiliation(s)
- Trias Thireou
- Physics Lab, Department of Science, Department of Biotechnology, Agricultural University of Athens, 75 Iera Odos, Votanikos, Athens 118-55, Greece and Centre de recherche de restauration des musées de France, C2RMF-U.M.R. 171 du C.N.R.S., Palais du Louvre, 75001 Paris, France
| | - Vassilis Atlamazoglou
- Physics Lab, Department of Science, Department of Biotechnology, Agricultural University of Athens, 75 Iera Odos, Votanikos, Athens 118-55, Greece and Centre de recherche de restauration des musées de France, C2RMF-U.M.R. 171 du C.N.R.S., Palais du Louvre, 75001 Paris, France
| | - Manolis Levakis
- Physics Lab, Department of Science, Department of Biotechnology, Agricultural University of Athens, 75 Iera Odos, Votanikos, Athens 118-55, Greece and Centre de recherche de restauration des musées de France, C2RMF-U.M.R. 171 du C.N.R.S., Palais du Louvre, 75001 Paris, France
| | - Elias Eliopoulos
- Physics Lab, Department of Science, Department of Biotechnology, Agricultural University of Athens, 75 Iera Odos, Votanikos, Athens 118-55, Greece and Centre de recherche de restauration des musées de France, C2RMF-U.M.R. 171 du C.N.R.S., Palais du Louvre, 75001 Paris, France
| | - Athanassios Hountas
- Physics Lab, Department of Science, Department of Biotechnology, Agricultural University of Athens, 75 Iera Odos, Votanikos, Athens 118-55, Greece and Centre de recherche de restauration des musées de France, C2RMF-U.M.R. 171 du C.N.R.S., Palais du Louvre, 75001 Paris, France
| | - George Tsoucaris
- Physics Lab, Department of Science, Department of Biotechnology, Agricultural University of Athens, 75 Iera Odos, Votanikos, Athens 118-55, Greece and Centre de recherche de restauration des musées de France, C2RMF-U.M.R. 171 du C.N.R.S., Palais du Louvre, 75001 Paris, France
| | - Kostas Bethanis
- Physics Lab, Department of Science, Department of Biotechnology, Agricultural University of Athens, 75 Iera Odos, Votanikos, Athens 118-55, Greece and Centre de recherche de restauration des musées de France, C2RMF-U.M.R. 171 du C.N.R.S., Palais du Louvre, 75001 Paris, France
- *To whom correspondence should be addressed. +30 210 5294211+30 210 5294233
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Sá J, Chioato L, Ferreira T, de Oliveira A, Ruller R, Rosa J, Greene L, Ward R. Topology of the substrate-binding site of a Lys49-phospholipase A2 influences Ca2+-independent membrane-damaging activity. Biochem J 2005; 382:191-8. [PMID: 15147240 PMCID: PMC1133930 DOI: 10.1042/bj20031946] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2003] [Revised: 05/11/2004] [Accepted: 05/17/2004] [Indexed: 11/17/2022]
Abstract
BthTx-I (bothropstoxin-I) is a myotoxic Lys49-PLA2 (phospholipase A2 with Lys49) isolated from Bothrops jararacussu venom, which damages liposome membranes by a Ca2+-independent mechanism. The highly conserved Phe5/Ala102/Phe106 motif in the hydrophobic substrate-binding site of the Asp49-PLA2s is substituted by Leu5/Val102/Leu106 in the Lys49-PLA2s. The Leu5/Val102/Leu106 triad in BthTx-I was sequentially mutated via all single- and double-mutant combinations to the Phe5/Ala102/Phe106 mutant. All mutants were expressed as inclusion bodies in Escherichia coli, and the thermal stability (Tm), together with the myotoxic and Ca2+-independent membrane-damaging activities of the recombinant proteins, were evaluated. The far-UV CD profiles of the native, wild-type recombinant and the L106F (Leu106-->Phe) and L5F/F102A/L106F mutant proteins were identical. The L5F, V102A, L5F/V102A and V102A/L106F mutants showed distorted far-UV CD profiles; however, only the L5F and L5F/V102A mutants showed significant decreases in Tm. Alterations in the far-UV CD spectra correlated with decreased myotoxicity and protein-induced release of a liposome-entrapped marker. However, the V102A/L106F and L5F/V102A/L106F mutants, which presented high myotoxic activities, showed significantly reduced membrane-damaging activity. This demonstrates that the topology of the substrate-binding region of BthTx-I has a direct effect on the Ca2+-independent membrane damage, and implies that substrate binding retains an important role in this process.
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Affiliation(s)
- Juliana Martha Sá
- *Departamento de Bioquímica e Immunologia, FMRP-USP, Ribeirão Preto-SP, Brazil
| | - Lucimara Chioato
- *Departamento de Bioquímica e Immunologia, FMRP-USP, Ribeirão Preto-SP, Brazil
| | - Tatiana Lopes Ferreira
- †Departamento de Química, FFCLRP-USP, Avenida Bandeirantes 3900, CEP 14049-901, Ribeirão Preto-SP, Brazil
| | - Arthur H. C. de Oliveira
- ‡Departamento de Biologia Molecular e Celular e Bioagentes Patogênicos, FMRP-USP, Universidade de São Paulo, Ribeirão Preto-SP, Brazil
| | - Roberto Ruller
- ‡Departamento de Biologia Molecular e Celular e Bioagentes Patogênicos, FMRP-USP, Universidade de São Paulo, Ribeirão Preto-SP, Brazil
| | - José César Rosa
- ‡Departamento de Biologia Molecular e Celular e Bioagentes Patogênicos, FMRP-USP, Universidade de São Paulo, Ribeirão Preto-SP, Brazil
- §Centro de Química de Proteínas, FMRP-USP, Universidade de São Paulo, Ribeirão Preto-SP, Brazil
| | - Lewis J. Greene
- ‡Departamento de Biologia Molecular e Celular e Bioagentes Patogênicos, FMRP-USP, Universidade de São Paulo, Ribeirão Preto-SP, Brazil
- §Centro de Química de Proteínas, FMRP-USP, Universidade de São Paulo, Ribeirão Preto-SP, Brazil
| | - Richard J. Ward
- †Departamento de Química, FFCLRP-USP, Avenida Bandeirantes 3900, CEP 14049-901, Ribeirão Preto-SP, Brazil
- To whom correspondence should be addressed (email )
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36
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Ivanovski G, Petan T, Krizaj I, Gelb MH, Gubensek F, Pungercar J. Basic amino acid residues in the β-structure region contribute, but not critically, to presynaptic neurotoxicity of ammodytoxin A. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2004; 1702:217-25. [PMID: 15488774 DOI: 10.1016/j.bbapap.2004.09.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2004] [Revised: 08/30/2004] [Accepted: 09/01/2004] [Indexed: 11/26/2022]
Abstract
The molecular mechanism of action of presynaptically toxic secreted phospholipases A2 (sPLA2s) isolated from snake venoms is not completely understood. It has been proposed that the positive charge in the beta-structure region is important for their toxic activity. To test this hypothesis, we characterised several mutants of ammodytoxin A (AtxA) possessing substitution of all five basic residues in this region. The mutations had relatively little influence on the catalytic activity of AtxA, either on charge-neutral or anionic phospholipid vesicles. An exception was R72 when replaced by a hydrophobic (higher activity) or an acidic (lower activity) residue. Lethal potencies of the eight single site mutants were up to four times lower than that of the wild-type, whereas the triple mutant (K74S/H76S/R77L) was 13-fold less toxic. The substitutions also lowered the affinity of the toxin, slightly to moderately, for the neuronal receptors R25 and R180. Interaction with calmodulin was only slightly affected by substitutions of K86, more by those of the K74/H76/R77 cluster and most by those of R72 (up to 11-fold lower binding affinity). The results clearly indicate that the basic amino acid residues in the beta-region of AtxA contribute to, but are not necessary for, its neurotoxic effect.
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Affiliation(s)
- Gabriela Ivanovski
- Department of Biochemistry and Molecular Biology, Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
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37
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Ryu Y, Oh Y, Yoon J, Cho W, Baek K. Molecular characterization of a gene encoding the Drosophila melanogaster phospholipase A2. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1628:206-10. [PMID: 12932833 DOI: 10.1016/s0167-4781(03)00143-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A gene encoding Drosophila melanogaster secretory phospholipase A2 (sPLA2) has been cloned and characterized(.) The coding region of the sPLA2 gene was interrupted by a short intron, and codes for a signal peptide of 18 amino acids, followed by a mature protein of 168 amino acids, containing the structural features of group III sPLA2. From a Northern blot analysis, about a 1.0-kb Drosophila sPLA2 transcript was found to be expressed throughout its development and in both the adult bodies and heads. The recombinant Drosophila sPLA2 expressed and purified in Escherichia coli was found to be Ca(+2)-dependent and maximally active at pH 5.
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Affiliation(s)
- Yoonseok Ryu
- Institute of Life Sciences and Resources, and Graduate School of Biotechnology, Kyung Hee University, Yongin 449-701, South Korea
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38
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Scott KF, Graham GG, Bryant KJ. Secreted phospholipase A2 enzymes as therapeutic targets. Expert Opin Ther Targets 2003; 7:427-40. [PMID: 12783578 DOI: 10.1517/14728222.7.3.427] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Homology cloning through in silico database search analysis has led to the definition of ten structurally-related mammalian secreted phospholipase A(2) (sPLA(2)) enzyme forms at present, each expressed in a species-, genotype- and cell-type-specific manner and with different enzymatic properties. These studies have shown that models based on the premise that there is only one PLA(2) drug target are now inadequate. Type IIA sPLA(2) remains the most advanced clinical target, with rationally designed inhibitors in Phase II clinical trials. However, progress in our understanding of the functional role of the ten secreted enzymes in phospholipid (PL) metabolism and in eicosanoid-mediated disorders, together with their emerging activity-independent and receptor-mediated functions, is likely to significantly impact on current and future drug development efforts.
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Affiliation(s)
- Kieran F Scott
- St Vincent's Hospital Clinical School, School of Medical Sciences, The University of New South Wales, Sydney, Australia.
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Davidsen J, Jørgensen K, Andresen TL, Mouritsen OG. Secreted phospholipase A(2) as a new enzymatic trigger mechanism for localised liposomal drug release and absorption in diseased tissue. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1609:95-101. [PMID: 12507763 DOI: 10.1016/s0005-2736(02)00659-4] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Polymer-coated liposomes can act as versatile drug-delivery systems due to long vascular circulation time and passive targeting by leaky blood vessels in diseased tissue. We present an experimental model system illustrating a new principle for improved and programmable drug-delivery, which takes advantage of an elevated activity of secretory phospholipase A(2) (PLA(2)) at the diseased target tissue. The secretory PLA(2) hydrolyses a lipid-based proenhancer in the carrier liposome, producing lyso-phospholipids and free fatty acids, which are shown in a synergistic way to lead to enhanced liposome destabilization and drug release at the same time as the permeability of the target membrane is enhanced. Moreover, the proposed system can be made thermosensitive and offers a rational way for developing smart liposome-based drug delivery systems. This can be achieved by incorporating specific lipid-based proenhancers or prodestabilisers into the liposome carrier, which automatically becomes activated by PLA(2) only at the diseased target sites, such as inflamed or cancerous tissue.
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Affiliation(s)
- Jesper Davidsen
- Department of Pharmaceutics, The Royal Danish School of Pharmacy, Copenhagen, Denmark
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40
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Pan YH, Yu BZ, Singer AG, Ghomashchi F, Lambeau G, Gelb MH, Jain MK, Bahnson BJ. Crystal structure of human group X secreted phospholipase A2. Electrostatically neutral interfacial surface targets zwitterionic membranes. J Biol Chem 2002; 277:29086-93. [PMID: 12161451 DOI: 10.1074/jbc.m202531200] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The crystal structure of human group X (hGX) secreted phospholipase A2 (sPLA2) has been solved to a resolution of 1.97 A. As expected the protein fold is similar to previously reported sPLA2 structures. The active site architecture, including the positions of the catalytic residues and the first and second shell water around the Ca2+ cofactor, are highly conserved and remarkably similar to the group IB and group IIA enzymes. Differences are seen in the structures following the (1-12)-N-terminal helix and at the C terminus. These regions are proposed to interact with the substrate membrane surface. The opening to the active site slot is considerably larger in hGX than in human group IIA sPLA2. Furthermore, the electrostatic surface potential of the hGX interfacial-binding surface does not resemble that of the human group IIA sPLA2; the former is highly neutral, whereas the latter is highly cationic. The cationic residues on this face of group IB and IIA enzymes have been implicated in membrane binding and in k(cat*) allostery. In contrast, hGX does not show activation by the anionic charge at the lipid interface when acting on phospholipid vesicles or short-chain phospholipid micelles. Together, the crystal structure and kinetic results of hGX supports the conclusion that it is as active on zwitterionic as on anionic interfaces, and thus it is predicted to target the zwitterionic membrane surfaces of mammalian cells.
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Affiliation(s)
- Ying H Pan
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA
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41
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Abstract
Phospholipase A2 (PLA2) catalyzes the hydrolysis of the sn-2 position of membrane glycerophospholipids to liberate arachidonic acid (AA), a precursor of eicosanoids including prostaglandins and leukotrienes. The same reaction also produces lysophosholipids, which represent another class of lipid mediators. So far, at least 19 enzymes that possess PLA2 activity have been identified and cloned in mammals. The secretory PLA2 (sPLA2) family, in which 10 isozymes have been identified, consists of low-molecular weight, Ca2+-requiring secretory enzymes that have been implicated in a number of biological processes, such as modification of eicosanoid generation, inflammation, and host defense. The cytosolic PLA2 (cPLA2) family consists of three enzymes, among which cPLA2alpha has been paid much attention by researchers as an essential component of the initiation of AA metabolism. The activation of cPLA2alpha is tightly regulated by Ca2+ and phosphorylation. The Ca2+-independent PLA2 (iPLA2) family contains two enzymes and may play a major role in phospholipid remodeling. The platelet-activating factor (PAF) acetylhydrolase (PAF-AH) family contains four enzymes that exhibit unique substrate specificity toward PAF and/or oxidized phospholipids. Degradation of these bioactive phospholipids by PAF-AHs may lead to the termination of inflammatory reaction and atherosclerosis.
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Affiliation(s)
- Ichiro Kudo
- Department of Health Chemistry, School of Pharmaceutical Sciences, Showa University, Tokyo, Japan.
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42
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Abstract
In this study, the x-ray crystal structures of the calcium-free and calcium-bound forms of phospholipase A(2) (PLA(2)), produced extracellularly by Streptomyces violaceoruber, were determined by using the multiple isomorphous replacement and molecular replacement methods, respectively. The former and latter structures were refined to an R-factor of 18.8% at a 1.4-A resolution and an R-factor of 15.0% at a 1.6-A resolution, respectively. The overall structure of the prokaryotic PLA(2) exhibits a novel folding topology that demonstrates that it is completely distinct from those of eukaryotic PLA(2)s, which have been already determined by x-ray and NMR analyses. Furthermore, the coordination geometry of the calcium(II) ion apparently deviated from that of eukaryotic PLA(2)s. Regardless of the evolutionary divergence, the catalytic mechanism including the calcium(II) ion on secreted PLA(2) seems to be conserved between prokaryotic and eukaryotic cells. Demonstrating that the overall structure determined by x-ray analysis is almost the same as that determined by NMR analysis is useful to discuss the catalytic mechanism at the molecular level of the bacterial PLA(2).
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Affiliation(s)
- Yasuyuki Matoba
- Institute of Pharmaceutical Sciences, Faculty of Medicine, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8551, Japan
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43
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Sugiyama M, Ohtani K, Izuhara M, Koike T, Suzuki K, Imamura S, Misaki H. A novel prokaryotic phospholipase A2. Characterization, gene cloning, and solution structure. J Biol Chem 2002; 277:20051-8. [PMID: 11897786 DOI: 10.1074/jbc.m200264200] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Until now, phospholipase A(2) (PLA(2); EC 3.1.14) has been found only from eukaryotic sources. In the present study, we found a secreted PLA(2), which is produced by a soil bacterium, Streptomyces violaceoruber A-2688, demonstrating that the enzyme is the first phospholipase A(2) identified in prokaryote. After characterization of the novel PLA(2), a gene encoding the enzyme was cloned, sequenced, and overexpressed using a Streptomyces host-vector system. The amino acid sequence showed that the prokaryotic PLA(2) has only four cysteines and less homology to the eukaryotic ones, which have 12-16 cysteines. The solution structures of the prokaryotic PLA(2), bound and unbound with calcium(II) ion, were determined by using the NMR technique and structure calculation. The overall structure of the S. violaceoruber PLA(2), which is composed of only five alpha-helices, is completely different from those of eukaryotic PLA(2)s, which consist of beta-sheets and alpha-helices. The structure of the calcium-binding domain is obviously distinct from that without the ion; the ligands for the calcium(II) ion are the two carboxylates of Asp(43) (monodentate) and Asp(65) (bidentate), the carbonyl oxygen of Leu(44), and three water molecules. A calcium-binding experiment showed that the calcium dissociation constant ( approximately 5 mm) for the prokaryotic PLA(2) is much larger than those of eukaryotic ones.
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Affiliation(s)
- Masanori Sugiyama
- Institute of Pharmaceutical Sciences, Faculty of Medicine, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8551, Japan
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44
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Abstract
Secretory phospholipase A(2) (PLA(2)) can be proatherogenic both in the circulation and in the arterial wall. In blood plasma, PLA(2) can modify the circulating lipoproteins and so induce formation of small dense LDL particles, which are associated with increased risk for cardiovascular disease. In the arterial wall, PLA(2) can hydrolyze lipoproteins. The PLA(2)-modified lipoproteins bind tightly to extracellular proteoglycans, which may lead to their enhanced retention in the arterial wall. The modified lipoproteins may also aggregate and fuse, which can lead to accumulation of their lipids within the extracellular matrix. The PLA(2)-modified particles are more susceptible to further modifications by other enzymes and agents and can be taken up by macrophages, leading to accumulation of intracellular lipids. In addition, lysophospholipids and free fatty acids, the hydrolysis products of PLA(2), promote atherogenesis. Thus, these lipid mediators can be carried, either by the PLA(2)-modified lipoproteins themselves or by albumin, into the arterial cells, which then undergo functional alterations. This may, in turn, lead to specific changes in the extracellular matrix, which increase the retention and accumulation of lipoproteins within the matrix. In the present article, we discuss the possible actions of PLA(2) enzymes, especially PLA(2)-IIA, in the arterial wall during atherogenesis.
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Affiliation(s)
- E Hurt-Camejo
- AstraZeneca R&D, Cell Biology and Biochemistry, Mölndal, Sweden.
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45
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Affiliation(s)
- M Murakami
- Department of Health Chemistry, School of Pharmaceutical Sciences, Showa University, Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan
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46
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Stichtenoth DO, Thorén S, Bian H, Peters-Golden M, Jakobsson PJ, Crofford LJ. Microsomal prostaglandin E synthase is regulated by proinflammatory cytokines and glucocorticoids in primary rheumatoid synovial cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:469-74. [PMID: 11418684 DOI: 10.4049/jimmunol.167.1.469] [Citation(s) in RCA: 219] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The selective induction of PGE(2) synthesis in inflammation suggests that a PGE synthase may be linked to an inducible pathway for PG synthesis. We examined the expression of the recently cloned inducible microsomal PGE synthase (mPGES) in synoviocytes from patients with rheumatoid arthritis, its modulation by cytokines and dexamethasone, and its linkage to the inducible cyclooxygenase-2. Northern blot analysis showed that IL-1beta or TNF-alpha treatment induces mPGES mRNA from very low levels at baseline to maximum levels at 24 h. IL-1beta-induced mPGES mRNA was inhibited by dexamethasone in a dose-dependent fashion. Western blot analysis demonstrated that mPGES protein was induced by IL-1beta, and maximum expression was sustained for up to 72 h. There was a coordinated up-regulation of cyclooxygenase-2 protein, although peak expression was earlier. Differential Western blot analysis of the microsomal and the cytosolic fractions revealed that the induced expression of mPGES protein was limited to the microsomal fraction. The detected mPGES protein was catalytically functional as indicated by a 3-fold increase of PGES activity in synoviocytes following treatment with IL-1beta; this increased synthase activity was limited to the microsomal fraction. In summary, these data demonstrate an induction of mPGES in rheumatoid synoviocytes by proinflammatory cytokines. This novel pathway may be a target for therapeutic intervention for patients with arthritis.
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Affiliation(s)
- D O Stichtenoth
- Divisions of. Rheumatology and Pulmonary and Critical Care Medicine, University of Michigan, Ann Arbor, MI 48109, USA
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47
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Kim KP, Rafter JD, Bittova L, Han SK, Snitko Y, Munoz NM, Leff AR, Cho W. Mechanism of human group V phospholipase A2 (PLA2)-induced leukotriene biosynthesis in human neutrophils. A potential role of heparan sulfate binding in PLA2 internalization and degradation. J Biol Chem 2001; 276:11126-34. [PMID: 11118430 DOI: 10.1074/jbc.m004604200] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human group V phospholipase A(2) (hVPLA(2)) has been shown to have high activity to elicit leukotriene production in human neutrophils (Han, S. K., Kim, K. P., Koduri, R., Bittova, L., Munoz, N. M., Leff, A. R., Wilton, D. C., Gelb, M. H., and Cho, W. (1999) J. Biol. Chem. 274, 11881-11888). To determine the mechanism by which hVPLA(2) interacts with cell membranes to induce leukotriene formation, we mutated surface cationic residues and a catalytic residue of hVPLA(2) and measured the interactions of mutants with model membranes, immobilized heparin, and human neutrophils. These studies showed that cationic residues, Lys(7), Lys(11), and Arg(34), constitute a part of the interfacial binding surface of hVPLA(2), which accounts for its moderate preference for anionic membranes. Additionally, hVPLA(2) binds heparin with high affinity and has a well defined heparin-binding site. The site is composed of Arg(100), Lys(101), Lys(107), Arg(108), and Arg(111), and is spatially distinct from its interfacial binding surface. Importantly, the activities of the mutants to hydrolyze cell membrane phospholipids and induce leukotriene biosynthesis, when enzymes were added exogenously to neutrophils, correlated with their activities on phosphatidylcholine membranes but not with their affinities for anionic membranes and heparin. These results indicate that hVPLA(2) acts directly on the outer plasma membranes of neutrophils to release fatty acids and lysophospholipids. Further studies suggest that products of hVPLA(2) hydrolysis trigger the cellular leukotriene production by activating cellular enzymes involved in leukotriene formation. Finally, the temporal and spatial resolution of exogenously added hVPLA(2) and mutants suggests that binding to cell surface heparan sulfate proteoglycans is important for the internalization and clearance of cell surface-bound hVPLA(2).
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Affiliation(s)
- K P Kim
- Department of Chemistry, University of Illinois, Chicago, Illinois 60607, USA
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48
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Matoba Y, Kumagai T, Sugiyama M. Crystallization and preliminary X-ray diffraction studies of Streptomyces phospholipase A2 in a calcium-binding form. J Inorg Biochem 2000; 82:221-3. [PMID: 11132631 DOI: 10.1016/s0162-0134(00)00147-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Phospholipase A2 (PLA2) as a calcium-binding form, produced by Streptomyces violaceoruber, was crystallized in a form suitable for the diffraction analysis using the vapor diffusion method. Crystals were grown in 0.1 M Tris-HCl buffer (pH 8.5), 20 mM Ca2+ containing 50-60% (v/v) 2-methyl-2,4-pentanediol as a precipitant. They belong to the monoclinic space group P2(1), with the cell dimensions a=38.3 A, b=54.3 A, c=30.6 A, and beta=90.2 degrees. The crystals diffract the X-ray well and the diffraction intensity data were collected up to 1.6 A resolution. The crystal volume per unit mass, V(M) is 2.35 A3 Da(-1) with one molecule in the asymmetric unit, which corresponds to a solvent content of 47.7%.
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Affiliation(s)
- Y Matoba
- Institute of Pharmaceutical Sciences, Faculty of Medicine, Hiroshima University, Japan
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49
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Six DA, Dennis EA. The expanding superfamily of phospholipase A(2) enzymes: classification and characterization. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1488:1-19. [PMID: 11080672 DOI: 10.1016/s1388-1981(00)00105-0] [Citation(s) in RCA: 990] [Impact Index Per Article: 41.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The phospholipase A(2) (PLA(2)) superfamily consists of a broad range of enzymes defined by their ability to catalyze the hydrolysis of the middle (sn-2) ester bond of substrate phospholipids. The hydrolysis products of this reaction, free fatty acid and lysophospholipid, have many important downstream roles, and are derived from the activity of a diverse and growing superfamily of PLA(2) enzymes. This review updates the classification of the various PLA(2)'s now described in the literature. Four criteria have been employed to classify these proteins into one of the 11 Groups (I-XI) of PLA(2)'s. First, the enzyme must catalyze the hydrolysis of the sn-2 ester bond of a natural phospholipid substrate, such as long fatty acid chain phospholipids, platelet activating factor, or short fatty acid chain oxidized phospholipids. Second, the complete amino acid sequence of the mature protein must be known. Third, each PLA(2) Group should include all of those enzymes that have readily identifiable sequence homology. If more than one homologous PLA(2) gene exists within a species, then each paralog should be assigned a Subgroup letter, as in the case of Groups IVA, IVB, and IVC PLA(2). Homologs from different species should be classified within the same Subgroup wherever such assignments are possible as is the case with zebra fish and human Group IVA PLA(2) orthologs. The current classification scheme does allow for historical exceptions of the highly homologous Groups I, II, V, and X PLA(2)'s. Fourth, catalytically active splice variants of the same gene are classified as the same Group and Subgroup, but distinguished using Arabic numbers, such as for Group VIA-1 PLA(2) and VIA-2 PLA(2)'s. These four criteria have led to the expansion or realignment of Groups VI, VII and VIII, as well as the addition of Group XI PLA(2) from plants.
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Affiliation(s)
- D A Six
- Department of Chemistry and Biochemistry, MC 0601, Revelle College and School of Medicine, University of California, San Diego, La Jolla, CA 92093-0601, USA
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50
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Buckland AG, Wilton DC. The antibacterial properties of secreted phospholipases A(2). BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1488:71-82. [PMID: 11080678 DOI: 10.1016/s1388-1981(00)00111-6] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
There is a considerable body of evidence to support the antibacterial properties of the group IIa phospholipase A(2) as an important physiological function. This enzyme is able to act as an acute phase protein and may be part of the innate defence system of the body, acting in concert with other antibacterial proteins and peptides. The enzyme is most effective against Gram-positive bacteria whereas penetration of the lipopolysaccharide coat of Gram-negative bacteria requires bactericidal/permeability-increasing protein (BPI) as an additional permeabilizing factor. The global cationic nature of this protein (pI>10.5) appears to facilitate penetration of the anionic bacterial cell wall. In addition, the considerable preference of the enzyme for anionic phospholipid interfaces provides specificity toward anionic bacterial membranes as opposed to zwitterionic eucaryotic cell membranes.
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Affiliation(s)
- A G Buckland
- Division of Biochemistry and Molecular Biology, School of Biological Sciences, University of Southampton, Bassett Crescent East, SO16 7PX, Southampton, UK
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