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Alonazi M, Krayem N, Alharbi MG, Khayyat AIA, Alanazi H, Horchani H, Ben Bacha A. Functional Characterization and Anti-Tumor Effect of a Novel Group II Secreted Phospholipase A 2 from Snake Venom of Saudi Cerastes cerates gasperetti. Molecules 2023; 28:6517. [PMID: 37764293 PMCID: PMC10536776 DOI: 10.3390/molecules28186517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 08/31/2023] [Accepted: 09/05/2023] [Indexed: 09/29/2023] Open
Abstract
Secreted phospholipases A2 are snake-venom proteins with many biological activities, notably anti-tumor activity. Phospholipases from the same snake type but different geographical locations have shown similar biochemical and biological activities with minor differences in protein sequences. Thus, the discovery of a new phospholipase A2 with unique characteristics identified in a previously studied venom could suggest the origins of these differences. Here, a new Group II secreted phospholipase A2 (Cc-PLA2-II) from the snake venom of Saudi Cerastes cerastes gasperetti was isolated and characterized. The purified enzyme had a molecular weight of 13.945 kDa and showed high specific activity on emulsified phosphatidylcholine of 1560 U/mg at pH 9.5 and 50 °C with strict calcium dependence. Interestingly, stability in extreme pH and high temperatures was observed after enzyme incubation at several pH levels and temperatures. Moreover, a significant dose-dependent cytotoxic anti-tumor effect against six human cancer cell lines was observed with concentrations of Cc-PLA2 ranging from 2.5 to 8 µM. No cytotoxic effect on normal human umbilical-vein endothelial cells was noted. These results suggest that Cc-PLA2-II potentially has angiogenic activity of besides cytotoxicity as part of its anti-tumor mechanism. This study justifies the inclusion of this enzyme in many applications for anticancer drug development.
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Affiliation(s)
- Mona Alonazi
- Biochemistry Department, Science College, King Saud University, P.O. Box 22452, Riyadh 11495, Saudi Arabia; (M.A.); (M.G.A.); (A.I.A.K.); (H.A.)
| | - Najeh Krayem
- Laboratoire de Biochimie et de Génie Enzymatique des Lipases, ENIS, Université de Sfax, Route de Soukra 3038, Sfax BP 1173, Tunisia;
| | - Mona G. Alharbi
- Biochemistry Department, Science College, King Saud University, P.O. Box 22452, Riyadh 11495, Saudi Arabia; (M.A.); (M.G.A.); (A.I.A.K.); (H.A.)
| | - Arwa Ishaq A. Khayyat
- Biochemistry Department, Science College, King Saud University, P.O. Box 22452, Riyadh 11495, Saudi Arabia; (M.A.); (M.G.A.); (A.I.A.K.); (H.A.)
| | - Humidah Alanazi
- Biochemistry Department, Science College, King Saud University, P.O. Box 22452, Riyadh 11495, Saudi Arabia; (M.A.); (M.G.A.); (A.I.A.K.); (H.A.)
| | - Habib Horchani
- Science Department, College of Rivière-Du-Loup, Rivière-Du-Loup, QC G5R 1R1, Canada;
| | - Abir Ben Bacha
- Biochemistry Department, Science College, King Saud University, P.O. Box 22452, Riyadh 11495, Saudi Arabia; (M.A.); (M.G.A.); (A.I.A.K.); (H.A.)
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Darwish DA, Masoud HMM, Abdel-Monsef MM, Helmy MS, Zidan HA, Ibrahim MA. Phospholipase A2 enzyme from the venom of Egyptian honey bee Apis mellifera lamarckii with anti-platelet aggregation and anti-coagulation activities. J Genet Eng Biotechnol 2021; 19:10. [PMID: 33443641 PMCID: PMC7809086 DOI: 10.1186/s43141-020-00112-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 12/28/2020] [Indexed: 11/24/2022]
Abstract
Background Honey bee venom contains various enzymes with wide medical and pharmaceutical applications. Results The phospholipase A2 (PLA2) has been apparently purified from the venom of Egyptian honey bee (Apis mellifera lamarckii) 8.9-fold to a very high specific activity of 6033 U/mg protein using DEAE–cellulose and Sephacryl S-300 columns. The purified bee venom PLA2 is monomeric 16 kDa protein and has isoelectric point (pI) of 5.9. The optimal activity of bee venom PLA2 was attained at pH 8 and 45 °C. Cu2+, Ni2+, Fe2+, Ca2+, and Co2+ exhibited a complete activating effect on it, while Zn2+, Mn2+, NaN3, PMSF, N-Methylmaleimide, and EDTA have inhibitory effect. Conclusions The purified bee venom PLA2 exhibited anti-platelet aggregation and anti-coagulation activities which makes it promising agent for developing novel anti-clot formation drugs in future.
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Affiliation(s)
- Doaa A Darwish
- Molecular Biology Department, National Research Centre, 33 El Bohouth St. (former El Tahrir St.), Dokki, P.O. 12622, Giza, Egypt
| | - Hassan M M Masoud
- Molecular Biology Department, National Research Centre, 33 El Bohouth St. (former El Tahrir St.), Dokki, P.O. 12622, Giza, Egypt.
| | - Mohamed M Abdel-Monsef
- Molecular Biology Department, National Research Centre, 33 El Bohouth St. (former El Tahrir St.), Dokki, P.O. 12622, Giza, Egypt
| | - Mohamed S Helmy
- Molecular Biology Department, National Research Centre, 33 El Bohouth St. (former El Tahrir St.), Dokki, P.O. 12622, Giza, Egypt
| | - Hind A Zidan
- Plant Protection Research Institute, Agricultural Research Center, Giza, Egypt
| | - Mahmoud A Ibrahim
- Molecular Biology Department, National Research Centre, 33 El Bohouth St. (former El Tahrir St.), Dokki, P.O. 12622, Giza, Egypt
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Secreted Phospholipases A₂ from Animal Venoms in Pain and Analgesia. Toxins (Basel) 2017; 9:toxins9120406. [PMID: 29311537 PMCID: PMC5744126 DOI: 10.3390/toxins9120406] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 12/13/2017] [Accepted: 12/16/2017] [Indexed: 12/20/2022] Open
Abstract
Animal venoms comprise a complex mixture of components that affect several biological systems. Based on the high selectivity for their molecular targets, these components are also a rich source of potential therapeutic agents. Among the main components of animal venoms are the secreted phospholipases A2 (sPLA2s). These PLA2 belong to distinct PLA2s groups. For example, snake venom sPLA2s from Elapidae and Viperidae families, the most important families when considering envenomation, belong, respectively, to the IA and IIA/IIB groups, whereas bee venom PLA2 belongs to group III of sPLA2s. It is well known that PLA2, due to its hydrolytic activity on phospholipids, takes part in many pathophysiological processes, including inflammation and pain. Therefore, secreted PLA2s obtained from animal venoms have been widely used as tools to (a) modulate inflammation and pain, uncovering molecular targets that are implicated in the control of inflammatory (including painful) and neurodegenerative diseases; (b) shed light on the pathophysiology of inflammation and pain observed in human envenomation by poisonous animals; and, (c) characterize molecular mechanisms involved in inflammatory diseases. The present review summarizes the knowledge on the nociceptive and antinociceptive actions of sPLA2s from animal venoms, particularly snake venoms.
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Tracing the evolution of venom phospholipases A 2 in Gloydius strauchii and related pitvipers: A tale of two acidic isozymes. Toxicon 2017; 141:65-72. [PMID: 29191388 DOI: 10.1016/j.toxicon.2017.11.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 11/19/2017] [Accepted: 11/23/2017] [Indexed: 01/29/2023]
Abstract
Two acidic Asp49-PLA2s with Glu6 substitution and a neutral Lys49-PLA (designated Gst-K49) were cloned from G. strauchii venom glands, their full amino acid sequences were deduced. The predominant acidic PLA2 (designated Gst-E6a) contains 124 residues and the M18W30 substitutions, while the minor acidic PLA2 (designated Gst-E6b) contains 122 residues and the V18A30 substitutions. Their sequences are most similar to those of the respective orthologous PLA2s of G. intermedius venom. Gst-E6a and Gst-E6b appear to be paralogs and possibly have different predatory targets or functions. The LC-MS/MS results indicate the presence of only three PLA2 gene products in the crude venom, the relative expression levels were in the order of Gst-E6a ≫ Gst-E6b > Gst-K49, as confirmed by qPCR results. In contrast to other Gloydius, G. strauchii venom does not contain neurotoxic or basic anticoagulant Asp49-PLA2s, but Gst-K49 is the first Lys49-PLA2 identified in Gloydius venoms. However, its venom content is relatively low and its pI value 7.3 is much lower than those of other Lys49-PLA2s and. The Lys49-PLA2 genes appear to regress in the venom of most of Gloydius and related rattlesnake, and this evolutionary regression occurred before the dispersal of Asian pitvipers to the New World.
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Aird SD, da Silva NJ, Qiu L, Villar-Briones A, Saddi VA, Pires de Campos Telles M, Grau ML, Mikheyev AS. Coralsnake Venomics: Analyses of Venom Gland Transcriptomes and Proteomes of Six Brazilian Taxa. Toxins (Basel) 2017; 9:E187. [PMID: 28594382 PMCID: PMC5488037 DOI: 10.3390/toxins9060187] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Revised: 05/31/2017] [Accepted: 06/02/2017] [Indexed: 11/16/2022] Open
Abstract
Venom gland transcriptomes and proteomes of six Micrurus taxa (M. corallinus, M. lemniscatus carvalhoi, M. lemniscatus lemniscatus, M. paraensis, M. spixii spixii, and M. surinamensis) were investigated, providing the most comprehensive, quantitative data on Micrurus venom composition to date, and more than tripling the number of Micrurus venom protein sequences previously available. The six venomes differ dramatically. All are dominated by 2-6 toxin classes that account for 91-99% of the toxin transcripts. The M. s. spixii venome is compositionally the simplest. In it, three-finger toxins (3FTxs) and phospholipases A₂ (PLA₂s) comprise >99% of the toxin transcripts, which include only four additional toxin families at levels ≥0.1%. Micrurus l. lemniscatus venom is the most complex, with at least 17 toxin families. However, in each venome, multiple structural subclasses of 3FTXs and PLA₂s are present. These almost certainly differ in pharmacology as well. All venoms also contain phospholipase B and vascular endothelial growth factors. Minor components (0.1-2.0%) are found in all venoms except that of M. s. spixii. Other toxin families are present in all six venoms at trace levels (<0.005%). Minor and trace venom components differ in each venom. Numerous novel toxin chemistries include 3FTxs with previously unknown 8- and 10-cysteine arrangements, resulting in new 3D structures and target specificities. 9-cysteine toxins raise the possibility of covalent, homodimeric 3FTxs or heterodimeric toxins with unknown pharmacologies. Probable muscarinic sequences may be reptile-specific homologs that promote hypotension via vascular mAChRs. The first complete sequences are presented for 3FTxs putatively responsible for liberating glutamate from rat brain synaptosomes. Micrurus C-type lectin-like proteins may have 6-9 cysteine residues and may be monomers, or homo- or heterodimers of unknown pharmacology. Novel KSPIs, 3× longer than any seen previously, appear to have arisen in three species by gene duplication and fusion. Four species have transcripts homologous to the nociceptive toxin, (MitTx) α-subunit, but all six species had homologs to the β-subunit. The first non-neurotoxic, non-catalytic elapid phospholipase A₂s are reported. All are probably myonecrotic. Phylogenetic analysis indicates that the six taxa diverged 15-35 million years ago and that they split from their last common ancestor with Old World elapines nearly 55 million years ago. Given their early diversification, many cryptic micrurine taxa are anticipated.
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Affiliation(s)
- Steven D Aird
- Division of Faculty Affairs, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa-ken 904-0495, Japan.
- Ecology and Evolution Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa-ken 904-0495, Japan.
| | - Nelson Jorge da Silva
- Programa de Pós-Graduação em Ciências Ambientais e Saúde, Pontifícia Universidade Católica de Goiás, Goiânia, Goiás 74605-140, Brazil.
| | - Lijun Qiu
- Ecology and Evolution Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa-ken 904-0495, Japan.
| | - Alejandro Villar-Briones
- Research Support Division, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa-ken 904-0495, Japan.
| | - Vera Aparecida Saddi
- Programa de Pós-Graduação em Ciências Ambientais e Saúde, Pontifícia Universidade Católica de Goiás, Goiânia, Goiás 74605-140, Brazil.
- Laboratório de Oncogenética e Radiobiologia da Associação de Combate ao Câncer em Goiás, Universidade Federal de Goiás, Rua 239 no. 52-Setor Universitário, Goiânia, Goiás 74065-070, Brazil.
| | - Mariana Pires de Campos Telles
- Programa de Pós-Graduação em Ciências Ambientais e Saúde, Pontifícia Universidade Católica de Goiás, Goiânia, Goiás 74605-140, Brazil.
- Laboratório de Genética & Biodiversidade, Universidade Federal de Goiás, Goiânia, Goiás 74690-900, Brazil.
| | - Miguel L Grau
- Ecology and Evolution Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa-ken 904-0495, Japan.
| | - Alexander S Mikheyev
- Ecology and Evolution Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa-ken 904-0495, Japan.
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Accary C, Mantash A, Mallem Y, Fajloun Z, Elkak A. Separation and Biological Activities of Phospholipase A2 (Mb-PLA2) from the Venom of Montivipera bornmuelleri, a Lebanese Viper. J LIQ CHROMATOGR R T 2015. [DOI: 10.1080/10826076.2014.968660] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Claudine Accary
- Azm Center for Research in Biotechnology and its Applications, Doctoral School of Sciences and Technology, Lebanese University, Tripoli, Lebanon
| | - Aziza Mantash
- Laboratory of “Valorisation des Ressources Naturelles et Produits de Santé (VRNPS),” Doctoral School of Sciences and Technology, Lebanese University, Rafic Hariri University Campus, Hadath, Lebanon
| | - Yassine Mallem
- LUNAM, Oniris, Unit of Animal Pathophysiology and Functional Pharmacology, Nantes, France
| | - Ziad Fajloun
- Azm Center for Research in Biotechnology and its Applications, Doctoral School of Sciences and Technology, Lebanese University, Tripoli, Lebanon
| | - Assem Elkak
- Laboratory of “Valorisation des Ressources Naturelles et Produits de Santé (VRNPS),” Doctoral School of Sciences and Technology, Lebanese University, Rafic Hariri University Campus, Hadath, Lebanon
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Tsai IH, Tsai TS, Wang YM, Tu MC, Chang HC. Cloning and characterization of Trimeresurus gracilis venom phospholipases A2: Comparison with Ovophis okinavensis venom and the systematic implications. Toxicon 2012; 59:151-7. [DOI: 10.1016/j.toxicon.2011.10.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Revised: 09/27/2011] [Accepted: 10/27/2011] [Indexed: 11/28/2022]
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Marcon F, Nicholson GM. Identification of presynaptic neurotoxin complexes in the venoms of three Australian copperheads (Austrelaps spp.) and the efficacy of tiger snake antivenom to prevent or reverse neurotoxicity. Toxicon 2011; 58:439-52. [DOI: 10.1016/j.toxicon.2011.08.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Revised: 08/02/2011] [Accepted: 08/03/2011] [Indexed: 11/25/2022]
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Salvador GHM, Marchi-Salvador DP, Silveira LB, Soares AM, Fontes MRM. Crystallization and preliminary X-ray diffraction studies of BmooPLA2-I, a platelet-aggregation inhibitor and hypotensive phospholipase A2 from Bothrops moojeni venom. Acta Crystallogr Sect F Struct Biol Cryst Commun 2011; 67:900-2. [PMID: 21821890 PMCID: PMC3151123 DOI: 10.1107/s174430911102392x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Accepted: 06/18/2011] [Indexed: 11/10/2022]
Abstract
Phospholipases A(2) (PLA(2)s) are enzymes that cause the liberation of fatty acids and lysophospholipids by the hydrolysis of membrane phospholipids. In addition to their catalytic action, a wide variety of pharmacological activities have been described for snake-venom PLA(2)s. BmooPLA(2)-I is an acidic, nontoxic and catalytic PLA(2) isolated from Bothrops moojeni snake venom which exhibits an inhibitory effect on platelet aggregation, an immediate decrease in blood pressure, inducing oedema at a low concentration, and an effective bactericidal effect. BmooPLA(2)-I has been crystallized and X-ray diffraction data have been collected to 1.6 Å resolution using a synchrotron-radiation source. The crystals belonged to space group C222(1), with unit-cell parameters a = 39.7, b = 53.2, c = 89.2 Å. The molecular-replacement solution of BmooPLA(2)-I indicated a monomeric conformation, which is in agreement with nondenaturing electrophoresis and dynamic light-scattering experiments. A comparative study of this enzyme with the acidic PLA(2) from B. jararacussu (BthA-I) and other toxic and nontoxic PLA(2)s may provide important insights into the functional aspects of this class of proteins.
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Affiliation(s)
- Guilherme H. M. Salvador
- Departamento de Física e Biofísica, Instituto de Biociências, UNESP – Universidade Estadual Paulista, Botucatu-SP, Brazil
- Instituto Nacional de Ciência e Tecnologia em Toxinas, CNPq, Brazil
| | - Daniela P. Marchi-Salvador
- Departamento de Física e Biofísica, Instituto de Biociências, UNESP – Universidade Estadual Paulista, Botucatu-SP, Brazil
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, FCFRP, USP, Ribeirão Preto-SP, Brazil
| | - Lucas B. Silveira
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, FCFRP, USP, Ribeirão Preto-SP, Brazil
| | - Andreimar M. Soares
- Fundação Oswaldo Cruz, FIOCRUZ Rondônia e Centro de Estudos de Biomoléculas Aplicadas - CEBio, Núcleo de Saúde, Universidade Federal de Rondônia, Porto Velho-RO, Brazil
| | - Marcos R. M. Fontes
- Departamento de Física e Biofísica, Instituto de Biociências, UNESP – Universidade Estadual Paulista, Botucatu-SP, Brazil
- Instituto Nacional de Ciência e Tecnologia em Toxinas, CNPq, Brazil
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Georgieva D, Seifert J, Öhler M, von Bergen M, Spencer P, Arni RK, Genov N, Betzel C. Pseudechis australis Venomics: Adaptation for a Defense against Microbial Pathogens and Recruitment of Body Transferrin. J Proteome Res 2011; 10:2440-64. [DOI: 10.1021/pr101248e] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Dessislava Georgieva
- Institute of Biochemistry and Molecular Biology, University of Hamburg, Laboratory of Structural Biology of Infection and Inflammation, c/o DESY, Notkestrasse 85, Build. 22a, 22603 Hamburg, Germany
| | - Jana Seifert
- Department of Proteomics, Helmholtz Centre for Environmental Research-UFZ, Permoser Strasse 15, 04318 Leipzig, Germany
| | - Michaela Öhler
- Department of Proteomics, Helmholtz Centre for Environmental Research-UFZ, Permoser Strasse 15, 04318 Leipzig, Germany
| | - Martin von Bergen
- Department of Proteomics, Helmholtz Centre for Environmental Research-UFZ, Permoser Strasse 15, 04318 Leipzig, Germany
| | - Patrick Spencer
- Centro de Biotecnologia, Instituto de Pesquisas Energéticas e Nucleares, Av. Lineeu Prestes 2242, 05508-000 São Paulo, Brazil
| | - Raghuvir K. Arni
- Department of Physics, IBILCE/UNESP, Cristóvão Colombo 2265, CEP 15054-000, São José do Rio Preto, SP Brazil
| | - Nicolay Genov
- Institute of Organic Chemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
| | - Christian Betzel
- Institute of Biochemistry and Molecular Biology, University of Hamburg, Laboratory of Structural Biology of Infection and Inflammation, c/o DESY, Notkestrasse 85, Build. 22a, 22603 Hamburg, Germany
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Wang YM, Parmelee J, Guo YW, Tsai IH. Absence of phospholipase A(2) in most Crotalus horridus venom due to translation blockage: comparison with Crotalus horridus atricaudatus venom. Toxicon 2010; 56:93-100. [PMID: 20347857 DOI: 10.1016/j.toxicon.2010.03.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2010] [Revised: 03/15/2010] [Accepted: 03/18/2010] [Indexed: 11/24/2022]
Abstract
To investigate the peculiar absence of phospholipases A(2) (PLA(2)s) in most Crotalus horridus (CH) venom, we cloned and sequenced the venom PLA(2)s of three CH specimens from different regions. The results revealed that all the venom glands contained mRNAs that encoded an acidic PLA(2) (designated as either CH-E6 or CH-E6'). The predicted CH-E6 from the Iowan CH and CH-E6' from the South Carolinian CH differed by only one amino acid residue, while the PLA(2) cDNA cloned from the Kentuckian CH contained an early stop codon instead of a Tyr(22) codon. Only the individual South Carolinian CH venom was found to contain the CH-E6' protein whose mass was confirmed by MALDI-TOF analysis. Our results suggest that low PLA(2) expression levels in most CH venom can be attributed to translation blockage. We also purified two acidic PLA(2)s and canebrake toxin from the pooled venom of Crotalus horridus atricaudatus (neurotoxic CH subspecies). One of the acidic PLA(2)s was identical to CH-E6 and showed high lipolytic activity and weak anti-platelet activities. The possibility that C. h. atricaudatus could be a hybrid between CH and Crotalus scutulatus is discussed.
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Affiliation(s)
- Ying-Ming Wang
- Institute of Biological Chemistry, Academia Sinica, and Institute of Biochemical Sciences, National Taiwan University, P.O. Box 23-106, Taipei, Taiwan
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Marchi-Salvador DP, Fernandes CA, Silveira LB, Soares AM, Fontes MR. Crystal structure of a phospholipase A2 homolog complexed with p-bromophenacyl bromide reveals important structural changes associated with the inhibition of myotoxic activity. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2009; 1794:1583-90. [DOI: 10.1016/j.bbapap.2009.07.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2009] [Revised: 07/07/2009] [Accepted: 07/08/2009] [Indexed: 10/20/2022]
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14
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Purification, characterization and bactericidal activities of basic phospholipase A2 from the venom of Agkistrodon halys (Chinese pallas). Biochimie 2008; 90:1372-88. [DOI: 10.1016/j.biochi.2008.04.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2007] [Accepted: 04/11/2008] [Indexed: 11/18/2022]
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15
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Ambrosio ALB, Nonato MC, de Araújo HSS, Arni R, Ward RJ, Ownby CL, de Souza DHF, Garratt RC. A Molecular Mechanism for Lys49-Phospholipase A2 Activity Based on Ligand-induced Conformational Change. J Biol Chem 2005; 280:7326-35. [PMID: 15596433 DOI: 10.1074/jbc.m410588200] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Agkistrodon contortrix laticinctus myotoxin is a Lys(49)-phospholipase A(2) (EC 3.1.1.4) isolated from the venom of the serpent A. contortrix laticinctus (broad-banded copperhead). We present here three monomeric crystal structures of the myotoxin, obtained under different crystallization conditions. The three forms present notable structural differences and reveal that the presence of a ligand in the active site (naturally presumed to be a fatty acid) induces the exposure of a hydrophobic surface (the hydrophobic knuckle) toward the C terminus. The knuckle in A. contortrix laticinctus myotoxin involves the side chains of Phe(121) and Phe(124) and is a consequence of the formation of a canonical structure for the main chain within the region of residues 118-125. Comparison with other Lys(49)-phospholipase A(2) myotoxins shows that although the knuckle is a generic structural motif common to all members of the family, it is not readily recognizable by simple sequence analyses. An activation mechanism is proposed that relates fatty acid retention at the active site to conformational changes within the C-terminal region, a part of the molecule that has long been associated with Ca(2+)-independent membrane damaging activity and myotoxicity. This provides, for the first time, a direct structural connection between the phospholipase "active site" and the C-terminal "myotoxic site," justifying the otherwise enigmatic conservation of the residues of the former in supposedly catalytically inactive molecules.
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Affiliation(s)
- Andre L B Ambrosio
- Centro de Biotecnologia Molecular Estrutural, Instituto de Física de São Carlos, USP, São Carlos-SP CEP 13560-970, Brazil
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Armugam A, Gong N, Li X, Siew PY, Chai SC, Nair R, Jeyaseelan K. Group IB phospholipase A2 from Pseudonaja textilis. Arch Biochem Biophys 2004; 421:10-20. [PMID: 14678780 DOI: 10.1016/j.abb.2003.09.045] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Pseudonaja textilis, an Australian Elapid, is known to produce a highly toxic venom. Both protein profiling and N-terminal sequence analysis showed the presence of four new phospholipases A(2) in this venom. Besides being non-lethal, the phospholipase A(2) proteins were found to be moderately active enzymes and they showed procoagulant property. cDNA cloning and characterization indicated the presence of two isoforms of PLA(2) proteins in a single snake, each containing the "pancreatic loop," characteristic of group IB phospholipase A(2). The genomic cloning also confirmed the presence of two genes each containing four exons that are interrupted by three introns. Phylogenetic analysis showed that the venom group IB PLA(2) gene is primitive and could have evolved from the same ancestor as the mammalian and venom group IA PLA(2) genes. In the present study, we report that the Pt-PLA2 gene could be responsible for the production of PL1, 2, and 3 possibly via RNA editing process.
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Affiliation(s)
- Arunmozhiarasi Armugam
- Department of Biochemistry, Faculty of Medicine, National University of Singapore 8 Medical Drive, Singapore 117597, Singapore
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17
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Yang WL, Peng LS, Zhong XF, Wei JW, Jiang XY, Ye LT, Zou L, Tu HB, Wu WY, Xu AL. Functional expression and characterization of a recombinant phospholipase A2 from sea snake Lapemis hardwickii as a soluble protein in E. coli. Toxicon 2003; 41:713-21. [PMID: 12727275 DOI: 10.1016/s0041-0101(03)00047-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Three full-length phospholipase A(2) (PLA(2)) cDNAs from sea snake Lapemis hardwickii venom were cloned and sequenced in our previous study. In order to investigate their biological functions, we established a fusion expression system for PLA(2)-9 in E. coli. The open reading frame encoding mature peptide of PLA(2)-9 was subcloned into the vector pTRX. The Trx-PLA(2)-9 fusion protein was expressed as a soluble protein by IPTG induction at 23 degrees C. The fusion protein was purified with metal-chelate affinity chromatography and then cleaved by enterokinase. The mature recombinant PLA(2)-9 was further purified by ion-exchange chromatography and a final yield of approximately 2.5mg pure PLA(2)-9 from 1l of bacteria culture was obtained. The catalytic activity of recombinant PLA(2)-9 (rPLA(2)-9) was measured and found to be similar to native enzyme. As the Austrelaps superbus PLA(2), which shares 90% nucleotide sequence similarity to PLA(2)-9, the rPLA(2)-9 displayed the anti-platelet aggregation effect. Site-directed mutagenesis of the two conserved residues, His-48 and Asp-49, resulted in the loss of catalytic activity, however did not affect the inhibition effect of platelet aggregation suggesting that these two activities of sea snake PLA(2)-9 may be dissociated.
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Affiliation(s)
- Wen-Li Yang
- The Open Laboratory for Marine Functional Genomics of State High-Tech Development, Department of Biochemistry, College of Life Sciences, Sun Yat-Sen (Zhongshan) University, Guangzhou 510275, People's Republic of China
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18
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Tsai IH, Wang YM, Chen YH, Tu AT. Geographic variations, cloning, and functional analyses of the venom acidic phospholipases A2 of Crotalus viridis viridis. Arch Biochem Biophys 2003; 411:289-96. [PMID: 12623078 DOI: 10.1016/s0003-9861(02)00747-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Geographic venom samples of Crotalus viridis viridis were obtained from South Dakota, Wyoming, Colorado, Oklahoma, Texas, New Mexico, and Arizona. From these samples, the phospholipases A(2) (PLA(2)s) were purified and their N-terminal sequences, precise masses, and in vitro enzymatic activities were determined. We purified two to four distinct acidic PLA(2)s from each sample; some of them displayed different inhibition specificities toward mammalian platelets. One of the acidic PLA(2)s induced edema, but had no anti-platelet activity. There was also a common basic PLA(2) myotoxin in all the samples. We have cloned five acidic PLA(2)s and several hybrid-like nonexpressing PLA(2)s. Molecular masses and N-terminal sequences of the purified PLA(2)s were matched with those deduced from the cDNA sequences, and the complete amino acid sequences of five novel acidic PLA(2)s were thus solved. They share 78% or greater sequence identity, and a cladogram based on the sequences of many venom acidic PLA(2)s of New World pit vipers revealed at least two subtypes. The results contribute to a better understanding of the ecogenetic adaptation of rattlesnakes and the structure-activity relationships and evolution of the acidic PLA(2)s in pit viper venom.
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Affiliation(s)
- Inn Ho Tsai
- Institute of Biological Chemistry, Academia Sinica, National Taiwan University, Taipei, Taiwan.
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19
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Hodgson WC, Eriksson CO, Alewood PF, Fry BG. Comparison of the in vitro neuromuscular activity of venom from three Australian snakes (Hoplocephalus stephensi, Austrelaps superbus and Notechis scutatus): efficacy of tiger snake antivenom. Clin Exp Pharmacol Physiol 2003; 30:127-32. [PMID: 12603339 DOI: 10.1046/j.1440-1681.2003.03816.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
1. Tiger snake antivenom, raised against Notechis scutatus venom, is indicated not only for the treatment of envenomation by this snake, but also that of the copperhead (Austrelaps superbus) and Stephen's banded snake (Hoplocephalus stephensi). The present study compared the neuromuscular pharmacology of venom from these snakes and the in vitro efficacy of tiger snake antivenom. 2. In chick biventer cervicis muscle and mouse phrenic nerve diaphragm preparations, all venoms (3-10 microg/mL) produced inhibition of indirect twitches. In the biventer muscle, venoms (10 micro g/mL) inhibited responses to acetylcholine (1 mmol/L) and carbachol (20 micromol/L), but not KCl (40 mmol/L). The prior (10 min) administration of 1 unit/mL antivenom markedly attenuated the neurotoxic effects of A. superbus and N. scutatus venoms (10 microg/mL), but was less effective against H. stephensi venom (10 microg/mL); 5 units/mL antivenom attenuated the neurotoxic activity of all venoms. 3. Administration of 5 units/mL antivenom at t90 partially reversed, over a period of 3 h, the inhibition of twitches produced by N. scutatus (10 microg/mL; 41% recovery), A. superbus (10 microg/mL; 25% recovery) and H. stephensi (10 microg/mL; 50% recovery) venoms. All venoms (10-100 microg/mL) also displayed signs of in vitro myotoxicity. 4. The results of the present study indicate that all three venoms contain neurotoxic activity that is effectively attenuated by tiger snake antivenom.
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Affiliation(s)
- Wayne C Hodgson
- Monash Venom Group, Department of Pharmacology, Monash University, Clayton, Australian Venom Research Unit, Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia.
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20
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Kanashiro MM, de Cássia M Escocard R, Petretski JH, Prates MV, Alves EW, Machado OLT, da Silva WD, Kipnis TL. Biochemical and biological properties of phospholipases A(2) from Bothrops atrox snake venom. Biochem Pharmacol 2002; 64:1179-86. [PMID: 12234622 DOI: 10.1016/s0006-2952(02)01288-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Phospholipases A(2) (PLA(2)s), of molecular mass 13-15kDa, are commonly isolated from snake venom. Two myotoxins with PLA(2) activity, BaPLA(2)I and BaPLA(2)III, with estimated molecular masses of 15kDa were isolated from the venom of Bothrops atrox using Sephacryl S-100-HR and reverse-phase chromatography. BaPLA(2)I was basic, with a pI of 9.1, while BaPLA(2)III was neutral with a pI of 6.9. On a molecular basis, BaPLA(2)III exhibited higher catalytic activity on synthetic substrates than BaPLA(2)I. Comparison of the N-terminal residues of BaPLA(2)I with other PLA(2) proteins from snake venoms showed that it has the highest homology (94%) with B. asper myotoxin II and homology with a PLA(2) Lys(49) from B. atrox (89%). In contrast, BaPLA(2)III demonstrated 75, 72, and 71% homology with PLA(2) from Vipera ammodytes meridionalis, B. jararacussu, and B. jararaca, respectively. BaPLA(2)I and BaPLA(2)III were capable, in vitro, of inducing mast cell degranulation and, in vivo, of causing creatine kinase release, edema, and myonecrosis typical of PLA(2)s from snake venoms, characterized by rapid disruption of the plasma membrane as indicated by clumping of myofilaments and necrosis of affected skeletal muscle cells. BaPLA(2)I- and BaPLA(2)III-specific monoclonal and polyclonal antibodies, although incapable of neutralizing PLA(2) edematogenic activity, blocked myonecrosis efficiently in an in vivo neutralization assay. The results presented herein suggest that the biological active site responsible for edema induction by these two PLA(2) enzymes is distinct from the myonecrosis active site and is not dependent upon the catalytic activity of the PLA(2) enzyme.
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Affiliation(s)
- Milton M Kanashiro
- Laboratório de Biologia do Reconhecer, Centro de Biociências e Biotecnologia - LBR, Universidade Estadual do Norte Fluminense, Av. Alberto Lamego, 2000, Campos dos Goytacazes, Rio de Janeiro, Brazil
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21
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Singh SB, Armugam A, Kini RM, Jeyaseelan K. Phospholipase A(2) with platelet aggregation inhibitor activity from Austrelaps superbus venom: protein purification and cDNA cloning. Arch Biochem Biophys 2000; 375:289-303. [PMID: 10700385 DOI: 10.1006/abbi.1999.1672] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Four phospholipase A(2) (PLA(2)) enzymes (Superbins a, b, c, and d) with varying platelet aggregation inhibitor activities have been purified from Austrelaps superbus by a combination of gel filtration, ion-exchange, and reversed-phase high-pressure liquid chromatography. Purity and homogeneity of the superbins have been confirmed by high-performance capillary zone electrophoresis and mass spectrometry. The electron spray ionization mass spectrometry data showed that their molecular masses range from 13,140 to 13,236 Da. Each of the proteins has been found to be basic and exhibit varying degrees of PLA(2) activity. They also displayed different platelet aggregation inhibitory activities. Superbin a was found to possess the most potent inhibitory activity with an IC(50) of 9.0 nM, whereas Superbin d was found to be least effective with an IC(50) of 3.0 microM. Superbins b and c were moderately effective with IC(50) values of 0.05 and 0.5 microM, respectively. The amino-terminal sequencing confirmed the identity of these superbins. cDNA cloning resulted in the identification of 17 more PLA(2) isoforms in A. superbus venom. It has also provided complete information on the precursor PLA(2). The precursor PLA(2) contained a 27-amino-acid signal peptide and 117- to 125-amino-acid PLA(2) (molecular mass ranging from 13,000 to 14,000 Da). Two of these PLA(2) enzymes resembled more closely (87%) Superbin a in structure. Two unique PLA(2) enzymes containing an extra pancreatic loop also have been identified among the isoforms.
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Affiliation(s)
- S B Singh
- Department of Biochemistry, National University of Singapore, 10 Medical Drive, Singapore, 119260
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22
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Gao R, Kini RM, Gopalakrishnakone P. Purification, properties, and amino acid sequence of a hemoglobinuria-inducing phospholipase A(2), MiPLA-1, from Micropechis ikaheka venom. Arch Biochem Biophys 1999; 369:181-92. [PMID: 10462455 DOI: 10.1006/abbi.1999.1347] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Dark-colored urine is one of the clinical symptoms of envenomation by Micropechis ikaheka (New Guinea small-eyed snake). We have purified a phospholipase A(2), MiPLA-1, which induces dark-colored urine in experimental mice, to homogeneity. The analysis of the dark-colored urine by electrophoresis and N-terminal sequence determination indicated that the color of mouse urine is due to hemoglobin in the urine but not myoglobin. MiPLA-1 is the first hemoglobinuria-inducing toxin. Insignificant hemolytic activity of MiPLA-1 indicates that hemoglobinuria is not due to lysis of erythrocytes by MiPLA-1. This suggests that hemoglobinuria induced by MiPLA-1 may be due to kidney leakage caused by unknown mechanisms. MiPLA-1 also showed other biological effects, including myotoxicity as well as anticoagulant and antiplatelet effects. Structural studies show that MiPLA-1 is a basic protein with a molecular mass of 14041.60 +/- 1.78 as determined by electrospray mass spectrometry. We have determined the complete amino acid sequence of MiPLA-1. It is a 124-amino-acid protein with a "pancreatic loop" and belongs to group IB phospholipase A(2) enzymes. Two short segments flanked by proline brackets are found in the sequence of MiPLA-1. These segments are on the surface of the molecule and hence may be involved in protein-protein recognition.
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Affiliation(s)
- R Gao
- Department of Anatomy, Faculty of Medicine, Faculty of Science, National University of Singapore, 10 Kent Ridge Crescent, Singapore, 119260, Singapore
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23
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Abstract
A comprehensive review of venom components isolated thus far from Australian elapids. Illustrated is that a tremendous structural homology exists among the components but this homology is not representative of the functional diversity. Further, the review illuminates the overlooked species and areas of research.
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Affiliation(s)
- B G Fry
- Peptide Laboratory, Centre for Drug Design and Development, University of Queensland, St. Lucia, Australia
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24
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Abstract
Snake venoms are complex mixtures containing many different biologically active proteins and peptides. A number of these proteins interact with components of the human hemostatic system. This review is focused on those venom constituents which affect the blood coagulation pathway, endothelial cells, and platelets. Only highly purified and well characterized snake venom proteins will be discussed in this review. Hemostatically active components are distributed widely in the venom of many different snake species, particularly from pit viper, viper and elapid venoms. The venom components can be grouped into a number of different categories depending on their hemostatic action. The following groups are discussed in this review: (i) enzymes that clot fibrinogen; (ii) enzymes that degrade fibrin(ogen); (iii) plasminogen activators; (iv) prothrombin activators; (v) factor V activators; (vi) factor X activators; (vii) anticoagulant activities including inhibitors of prothrombinase complex formation, inhibitors of thrombin, phospholipases, and protein C activators; (viii) enzymes with hemorrhagic activity; (ix) enzymes that degrade plasma serine proteinase inhibitors; (x) platelet aggregation inducers including direct acting enzymes, direct acting non-enzymatic components, and agents that require a cofactor; (xi) platelet aggregation inhibitors including: alpha-fibrinogenases, 5'-nucleotidases, phospholipases, and disintegrins. Although many snake venoms contain a number of hemostatically active components, it is safe to say that no single venom contains all the hemostatically active components described here. Several venom enzymes have been used clinically as anticoagulants and other venom components are being used in pre-clinical research to examine their possible therapeutic potential. The disintegrins are an interesting group of peptides that contain a cell adhesion recognition motif, Arg-Gly-Asp (RGD), in the carboxy-terminal half of their amino acid sequence. These agents act as fibrinogen receptor (integrin GPIIb/IIIa) antagonists. Since this integrin is believed to serve as the final common pathway leading to the formation of platelet-platelet bridges and platelet aggregation, blockage of this integrin leads to inhibition of platelet aggregation regardless of the stimulating agent. Clinical trials suggest that platelet GPIIb/IIIa blockade is an effective therapy for the thrombotic events and restenosis frequently accompanying cardiovascular and cerebrovascular disease. Therefore, because of their clinical poten tial, a large number of disintegrins have been isolated and characterized.
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Affiliation(s)
- F S Markland
- Cancer Research Laboratory #106, University of Southern California, School of Medicine, Los Angeles 90033, USA
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25
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Abstract
The protein content of many snake venoms often includes one or more phospholipases A2 (PLA2). In recent years a growing number of venoms from snakes of Agkistrodon, Bothrops and Trimeresurus species have been shown to contain a catalytically inactive PLA2-homologue in which the highly conserved aspartic acid at position 49 (Asp49) is substituted by lysine (Lys49). Although demonstrating little or no catalytic activity, these Lys49-PLA2s disrupt membranes by a Ca2+-independent mechanism of action. In addition, this family of PLA2s demonstrates myotoxic and cytolytic pharmacological activities, however the structural bases underlying these functional properties are poorly understood. Through the application of X-ray crystallography in combination with biophysical and bioinformatics techniques, we are studying structure/function relationships of Lys49-PLA2s. We here present results of a systematic X-ray crystallographic and amino acid sequence analysis study of Lys49 PLA2s and propose a model to explain the Ca2+-independent membrane damaging activity.
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Affiliation(s)
- R J Ward
- Department of Physics, IBILCE-UNESP, Sao Jose do Rio Preto SP, Brazil
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26
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Chow G, Subburaju S, Kini RM. Purification, characterization, and amino acid sequence determination of acanthins, potent inhibitors of platelet aggregation from Acanthophis antarcticus (common death adder) venom. Arch Biochem Biophys 1998; 354:232-8. [PMID: 9637731 DOI: 10.1006/abbi.1998.0685] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Venom of Acanthophis antarcticus, a common death adder, exhibits potent antiplatelet effects. By a combination of gel-filtration, cation-exchange, and reversed-phase chromatographic methods, two inhibitors of platelet aggregation, named acanthin I and II, were purified to homogeneity as assessed by capillary electrophoresis and electrospray mass spectrometry. These isoforms exhibit the most potent antiplatelet activity known thus far, with IC50 values of 7 nM for acanthin I and 4 nM for acanthin II in human whole blood when collagen was used as an agonist, whereas with ADP the IC50 values were 10 and 12 nM, respectively. Acanthin I and II are basic proteins with pIs of 10.2 +/- 0.1 and 10.4 +/- 0.1 and molecular weights of 12,844.58 +/- 0.61 and 12,895.63 +/- 0.48, respectively, as determined by electrospray mass spectrometry. They exhibit phospholipase enzyme activity, and acanthin I and II hydrolyzed 51. 57 +/- 1.30 and 46.85 +/- 2.90 micromol of phosphatidylcholine/min/mg, respectively. The complete amino acid sequences of acanthin I and II showed that they have a high homology with each other and with other elapids' phospholipase A2 neurotoxin, especially pseudexin A.
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Affiliation(s)
- G Chow
- Faculty of Science, National University of Singapore, 119260, Singapore
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27
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Canduri F, Mancuso LC, Soares AM, Giglio JR, Ward RJ, Arni RK. Crystallization of piratoxin I, a myotoxic Lys49-phospholipase A2 homologue isolated from the venom of Bothrops pirajai. Toxicon 1998; 36:547-51. [PMID: 9637374 DOI: 10.1016/s0041-0101(97)00120-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Large single crystals of piratoxin I. a Lys49-PLA2 homologue with low enzymatic activity, have been obtained. The crystals belong to the orthorhombic system space group P2(1)2(1)2(1), and diffract X-rays to a resolution of 2.8 A. Preliminary analysis reveals the presence of two molecules in the crystallographic asymmetric unit.
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Affiliation(s)
- F Canduri
- Departamento de Física, IBILCE/UNESP, São José do Rio Preto, SP, Brazil
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28
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da Silva Giotto MT, Garratt RC, Oliva G, Mascarenhas YP, Giglio JR, Cintra AC, de Azevedo WF, Arni RK, Ward RJ. Crystallographic and spectroscopic characterization of a molecular hinge: conformational changes in bothropstoxin I, a dimeric Lys49-phospholipase A2 homologue. Proteins 1998; 30:442-54. [PMID: 9533628 DOI: 10.1002/(sici)1097-0134(19980301)30:4<442::aid-prot11>3.0.co;2-i] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Bothropstoxin I (BthTX-I) from the venom of Bothrops jararacussu is a myotoxic phospholipase A2 (PLA2) homologue which, although catalytically inactive due to an Asp49-->Lys substitution, disrupts the integrity of lipid membranes by a Ca2+-independent mechanism. The crystal structures of two dimeric forms of BthTX-I which diffract X-rays to resolutions of 3.1 and 2.1 angstroms have been determined. The monomers in both structures are related by an almost perfect twofold axis of rotation and the dimer interfaces are defined by contacts between the N-terminal alpha-helical regions and the tips of the beta-wings of partner monomers. Significant differences in the relative orientation of the monomers in the two crystal forms results in "open" and "closed" dimer conformations. Spectroscopic investigations of BthTX-I in solution have correlated these conformational differences with changes in the intrinsic fluorescence emission of the single tryptophan residues located at the dimer interface. The possible relevance of this structural transition in the Ca2+-independent membrane damaging activity is discussed.
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29
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Sim KL. Purification and preliminary characterisation of praelongin phospholipases, antiplatelet agents from the snake venom of Acanthophis praelongus. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1379:198-206. [PMID: 9528655 DOI: 10.1016/s0304-4165(97)00097-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Three praelongin phospholipases were chromatographically purified from the snake venom of Acanthophis praelongus. The purity and homogeneity of the praelongins were assessed by RP-HPLC, HPCE and mass spectrometry. The purified enzymes, praelongins 2bIII, 2cII and 2cIV were found to have phospholipase A2 activities with specific activities of 31.4 +/- 0.4, 326.1 +/- 10.2 and 362.5 +/- 12.0 U/mg, respectively. Mass spectrometry studies showed the molecular mass of praelongin 2bIII to be 12,782.9 +/- 2.6 and praelongins 2cII and 2cIV to have very similar molecular mass values, 12,971.4 +/- 4.5 and 12,971.9 +/- 3.6, respectively. However, platelet aggregation studies showed the praelongins to display different IC50 values, 180 microM for praelongin 2cII and 55 microM for praelongin 2cIV; praelongin 2bIII was found to be a more potent antiplatelet agent, having an IC50 of 0.65 microM. Praelongins 2bIII, 2cIV and 2cII were found to have pI values of 10.3 +/- 0.3, 9.6 +/- 0.6 and 9.4 +/- 0.6 as determined by HPCE. The antiplatelet potencies do not correspond to their in vitro phospholipase catalytic potencies, but appear to be related to the enzyme isoelectric points.
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Affiliation(s)
- K L Sim
- Bioscience Centre, Faculty of Science, National University of Singapore, Singapore.
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30
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Huang MZ, Gopalakrishnakone P, Kini RM. Role of enzymatic activity in the antiplatelet effects of a phospholipase A2 from Ophiophagus hannah snake venom. Life Sci 1997; 61:2211-7. [PMID: 9393940 DOI: 10.1016/s0024-3205(97)00923-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A phospholipase A2 (OHV A-PLA2) from the venom of Ophiophagus hannah (King cobra) is an acidic protein exhibiting antiplatelet activity. In in vitro tests, OHV APLA2 showed a marked inhibitory effect on platelet aggregation induced by ADP, collagen and arachidonic acid in both human whole blood and platelet-rich plasma in a dose-dependent manner. The antiplatelet effects of OHV A-PLA2 did not increase when preincubation times of platelets and OHV A-PLA2 were prolonged indicating phospholipid hydrolysis did not significantly contribute to the antiplatelet effects. Alkylation of active site His residue using p-bromophenacyl bromide resulted in the complete loss of enzymatic activity, but the modified enzyme retained more than 30% of its antiplatelet effects. These results indicate that the antiplatelet effects of OHV A-PLA2 appear to be independent of its enzymatic activity, and there are separate sites responsible for the catalytic and antiplatelet activities.
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Affiliation(s)
- M Z Huang
- Department of Anatomy, National University of Singapore, Singapore
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31
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Subburaju S, Kini RM. Isolation and purification of superbins I and II from Austrelaps superbus (copperhead) snake venom and their anticoagulant and antiplatelet effects. Toxicon 1997; 35:1239-50. [PMID: 9278973 DOI: 10.1016/s0041-0101(97)00014-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Two proteins with anticoagulant and antiplatelet activities were purified from Austrelaps superbus (copperhead) venom by gel filtration, ion-exchange and reverse-phase chromatographic methods. These purified proteins were designated superbins I and II. Superbin I was homogeneous, as indicated by electrospray ionization-mass spectrometry, with a mol. wt of 13,252.3 +/- 1.6, whereas superbin II contained two closely related proteins of mol. wts 13,235.5 +/- 1.1 and 13,212.9 +/- 1.2. Both superbins showed phospholipase A2 activity and exhibited weak anticoagulant effects when tested by one-step prothrombin time clotting assays. The 'dissection approach' was used to identify the coagulation complex(es) inhibited by these enzymes in the extrinsic coagulation cascade. The results indicate that both the enzymes inhibit the extrinsic tenase complex, but not the prothrombinase complex, similarly to other weakly anticoagulant phospholipases. Superbins I and II also inhibited aggregation of human platelets induced by collagen.
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Affiliation(s)
- S Subburaju
- Bioscience Centre, Faculty of Science, National University of Singapore, Singapore
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32
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Abstract
Phospholipases A2 (PLA2) are widely distributed in nature and are well characterized proteins with respect to their catalytic and pharmacological activities. A wealth of structural information has recently become available both from X-ray diffraction and NMR studies, and although a detailed model of the catalytic mechanism of PLA2 has been proposed, the structural bases of other aspects of PLA2 function, such as interfacial activation and venom PLA2 pharmacological activities, are still under debate. An appreciation of the PLA2 protein structure will yield new insights with regard to these activities. The salient structural features of the class I, II and III PLA2 are discussed with respect to their functional roles.
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Affiliation(s)
- R K Arni
- Department of Physics, IBILCE/UNESP, São Jose do Rio Preto, Brazil
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33
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Laing GD, Kamiguti AS, Wilkinson MC, Lowe GM, Theakston RD. Characterisation of a purified phospholipase A2 from the venom of the Papuan black snake (Pseudechis papuanus). BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1250:137-43. [PMID: 7632717 DOI: 10.1016/0167-4838(95)00081-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A neutral phospholipase A2 (PLA2) was separated from Pseudechis papuanus venom by a two-stage FPLC procedure of cation exhange and phenyl-Superose chromatography. It had a molecular mass of 15 kDa and a lower LD50 value than a co-separated haemorrhagic fraction, indicating a higher lethal potency. In vitro tests confirmed the powerful inhibition of platelet aggregation by the PLA2 and strong anticoagulant activity initially observed with whole venom. Ultrastructural studies showed that platelets lost their discoid shape and developed membranous projections with a general decrease in electron-density of the cytosol and disruption of the microfilaments following incubation with the enzyme. Amino acid sequence analysis of the N-terminus and some internal peptides demonstrated a high degree of homology with PLA2s from other Pseudechis venoms. Our results indicate that this fraction is the main agent responsible for the haemostatic disorders in envenomed patients.
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Affiliation(s)
- G D Laing
- Snake Venom Research Unit, Liverpool School of Tropical Medicine, UK
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Kamiguti AS, Laing GD, Lowe GM, Zuzel M, Warrell DA, Theakston RD. Biological properties of the venom of the Papuan black snake (Pseudechis papuanus): presence of a phospholipase A2 platelet inhibitor. Toxicon 1994; 32:915-25. [PMID: 7985196 DOI: 10.1016/0041-0101(94)90370-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The whole venom of Pseudechis papuanus, in addition to its anticoagulant activity, powerfully inhibited platelet aggregation induced by ADP, adrenaline, collagen, ristocetin and thrombin. High levels of phospholipase A2 (PLA2) activity were detected. A mild procoagulant activity was also observed. Following exposure of platelets to P. papuanus venom, platelet factor 3 (procoagulant platelet phospholipid) showed decreased cofactor activity in factor X activation by Russell's viper, venom suggesting that the venom PLA2 plays a major role in the inhibition of the coagulation mechanism. In vivo rodent assays confirmed the inhibitory effect on platelets and the haemorrhagic and neurotoxic activities. It is possible that PLA2 is responsible for anticoagulation and that this, combined with the effect on platelet aggregation, a mild procoagulant and a moderately potent haemorrhagin, is responsible for the haemorrhagic diathesis observed in systemically envenomed patients. Polyvalent (Australia-Papua New Guinea) Commonwealth Serum Laboratories antivenom, currently used for clinical treatment of snakebite in Papua New Guinea, proved highly effective against P. papuanus venom in rodent and in vitro assays, despite the absence of this particular venom from the immunising mixture.
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Affiliation(s)
- A S Kamiguti
- University Department of Haematology, Royal Liverpool Hospital, U.K
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