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Salvador GHM, Fernandes CAH, Borges RJ, Soares AM, Fontes MRM. Structural studies with crotoxin B from Crotalus durissus collilineatus venom suggest a heterodimeric assembly formed by two new isoforms. Biochimie 2024; 218:46-56. [PMID: 37659716 DOI: 10.1016/j.biochi.2023.08.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 08/07/2023] [Accepted: 08/31/2023] [Indexed: 09/04/2023]
Abstract
In accidents involving Crotalus snakes, the crotoxin complex (CTX) plays lethal action due to its neurotoxic activity. On the other hand, CTX have potential biotechnological application due to its anti-tumoral, anti-inflammatory, antimicrobial, analgesic and immunomodulatory properties. CTX is a heterodimer composed of Crotoxin A (CA or crotapotin), the acidic nontoxic and non-enzymatic component and; Crotoxin B (CB), a basic, toxic and catalytic PLA2. Currently, there are two classes of CTX isoforms, whose differences in their biological activities have been attributed to features presented in CB isoforms. Here, we present the crystal structure of CB isolated from the Crotalus durissus collilineatus venom. It amino acid sequence was assigned using the SEQUENCE SLIDER software, which revealed that the crystal structure is a heterodimer composed of two new CB isoforms (colCB-A and colCB-B). Bioinformatic and biophysical analyses showed that the toxin forms a tetrameric assembly in solution similar to CB from Crotalus durissus terrificus venom, despite some differences observed at the dimeric interface. By the previously proposed classification, the colCB-B presents features of the class I isoforms while colCB-A cannot be classified into classes I and II based on its amino acid sequence. Due to similar features observed for other CB isoforms found in the NCBI database and the results obtained for colCB-A, we suggest that there are more than two classes of CTX and CB isoforms in crotalic venoms.
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Affiliation(s)
- Guilherme H M Salvador
- Departamento de Biofísica e Farmacologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil
| | - Carlos A H Fernandes
- Departamento de Biofísica e Farmacologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil; UMR 7590, CNRS, Muséum National d'Histoire Naturelle, IRD, Institut de Minéralogie, Physique des Matériaux et de Cosmochimie (IMPMC), Sorbonne Université, Paris, France
| | - Rafael J Borges
- Departamento de Biofísica e Farmacologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil; Centro de Química Medicina (CQMED), Centro de Biologia Molecular e Engenharia Genética (CBMEG), Universidade de Estadual de Campinas (UNICAMP), Campinas, SP, Brazil
| | - Andreimar M Soares
- Laboratório de Biotecnologia de Proteínas e Compostos Bioativos Aplicados, Fundação Oswaldo Cruz (FIOCRUZ), Unidade Rondônia, Porto Velho, RO, Brazil; Inst Nac. de Epidemiologia da Amazônia Ocidental (INCT-EPIAMO), Rede de Pesquisa e Conhecimento de Excelência na Amazônia Ocidental (RED-CONEXAO), Brazil
| | - Marcos R M Fontes
- Departamento de Biofísica e Farmacologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil; Instituto de Estudos Avançados do Mar (IEAMar), Universidade Estadual Paulista (UNESP), São Vicente, SP, Brazil.
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Crotoxin B: Heterologous Expression, Protein Folding, Immunogenic Properties, and Irregular Presence in Crotalid Venoms. Toxins (Basel) 2022; 14:toxins14060382. [PMID: 35737043 PMCID: PMC9228539 DOI: 10.3390/toxins14060382] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 05/16/2022] [Accepted: 05/19/2022] [Indexed: 11/17/2022] Open
Abstract
Crotoxin complex CA/CB and crotamine are the main toxins associated with Crotalus envenomation besides the enzymatic activities of phospholipases (PLA2) and proteases. The neutralization at least of the crotoxin complex by neutralizing the subunit B could be a key in the production process of antivenoms against crotalids. Therefore, in this work, a Crotoxin B was recombinantly expressed to evaluate its capacity as an immunogen and its ability to produce neutralizing antibodies against crotalid venoms. A Crotoxin B transcript from Crotalus tzabcan was cloned into a pCR®2.1-TOPO vector (Invitrogen, Waltham, MA, USA) and subsequently expressed heterologously in bacteria. HisrCrotoxin B was extracted from inclusion bodies and refolded in vitro. The secondary structure of HisrCrotoxin B was comparable to the secondary structure of the native Crotoxin B, and it has PLA2 activity as the native Crotoxin B. HisrCrotoxin B was used to immunize rabbits, and the obtained antibodies partially inhibited the activity of PLA2 from C. tzabcan. The anti-HisrCrotoxin B antibodies neutralized the native Crotoxin B and the whole venoms from C. tzabcan, C. s. salvini, and C. mictlantecuhtli. Additionally, anti-HisrCrotoxin B antibodies recognized native Crotoxin B from different Crotalus species, and they could discriminate venom in species with high or low levels of or absence of Crotoxin B.
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Borges RJ, Salvador GHM, Pimenta DC, Dos Santos LD, Fontes MRM, Usón I. SEQUENCE SLIDER: integration of structural and genetic data to characterize isoforms from natural sources. Nucleic Acids Res 2022; 50:e50. [PMID: 35104880 PMCID: PMC9122596 DOI: 10.1093/nar/gkac029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 01/05/2022] [Accepted: 01/30/2022] [Indexed: 12/28/2022] Open
Abstract
Proteins isolated from natural sources can be composed of a mixture of isoforms with similar physicochemical properties that coexist in the final steps of purification. Yet, even where unverified, the assumed sequence is enforced throughout the structural studies. Herein, we propose a novel perspective to address the usually neglected sequence heterogeneity of natural products by integrating biophysical, genetic and structural data in our program SEQUENCE SLIDER. The aim is to assess the evidence supporting chemical composition in structure determination. Locally, we interrogate the experimental map to establish which side chains are supported by the structural data, and the genetic information relating sequence conservation is integrated into this statistic. Hence, we build a constrained peptide database, containing most probable sequences to interpret mass spectrometry data (MS). In parallel, we perform MS de novo sequencing with genomic-based algorithms to detect point mutations. We calibrated SLIDER with Gallus gallus lysozyme, whose sequence is unequivocally established and numerous natural isoforms are reported. We used SLIDER to characterize a metalloproteinase and a phospholipase A2-like protein from the venom of Bothrops moojeni and a crotoxin from Crotalus durissus collilineatus. This integrated approach offers a more realistic structural descriptor to characterize macromolecules isolated from natural sources.
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Affiliation(s)
- Rafael J Borges
- Departament of Biophysics and Pharmacology, Biosciences Institute, São Paulo State University (UNESP), Botucatu, São Paulo 18618-689, Brazil.,Crystallographic Methods, Institute of Molecular Biology of Barcelona (IBMB-CSIC), Barcelona 08028, Spain
| | - Guilherme H M Salvador
- Departament of Biophysics and Pharmacology, Biosciences Institute, São Paulo State University (UNESP), Botucatu, São Paulo 18618-689, Brazil
| | - Daniel C Pimenta
- Biochemistry and Biophysics Laboratory, Butantan Institute, São Paulo, São Paulo 05503-900, Brazil
| | - Lucilene D Dos Santos
- Graduate Program in Tropical Diseases, Botucatu Medical School (FMB), São Paulo State University (UNESP), Botucatu, São Paulo 18618-687, Brazil.,Biotechnology Institute (IBTEC), São Paulo State University (UNESP), Botucatu, São Paulo 18607-440, Brazil
| | - Marcos R M Fontes
- Departament of Biophysics and Pharmacology, Biosciences Institute, São Paulo State University (UNESP), Botucatu, São Paulo 18618-689, Brazil
| | - Isabel Usón
- Crystallographic Methods, Institute of Molecular Biology of Barcelona (IBMB-CSIC), Barcelona 08028, Spain.,ICREA, Pg. Lluís Companys 23, 08010 Barcelona, Spain
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Fernandes CAH, Pazin WM, Dreyer TR, Bicev RN, Cavalcante WLG, Fortes-Dias CL, Ito AS, Oliveira CLP, Fernandez RM, Fontes MRM. Biophysical studies suggest a new structural arrangement of crotoxin and provide insights into its toxic mechanism. Sci Rep 2017; 7:43885. [PMID: 28256632 PMCID: PMC5335569 DOI: 10.1038/srep43885] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 01/31/2017] [Indexed: 11/19/2022] Open
Abstract
Crotoxin (CTX) is the main neurotoxin found in Crotalus durissus rattlesnake venoms being composed by a nontoxic and non-enzymatic component (CA) and a toxic phospholipase A2 (CB). Previous crystallographic structures of CTX and CB provided relevant insights: (i) CTX structure showed a 1:1 molecular ratio between CA and CB, presenting three tryptophan residues in the CA/CB interface and one exposed to solvent; (ii) CB structure displayed a tetrameric conformation. This study aims to provide further information on the CTX mechanism of action by several biophysical methods. Our data show that isolated CB can in fact form tetramers in solution; however, these tetramers can be dissociated by CA titration. Furthermore, CTX exhibits a strong reduction in fluorescence intensity and lifetime compared with isolated CA and CB, suggesting that all tryptophan residues in CTX may be hidden by the CA/CB interface. By companying spectroscopy fluorescence and SAXS data, we obtained a new structural model for the CTX heterodimer in which all tryptophans are located in the interface, and the N-terminal region of CB is largely exposed to the solvent. Based on this model, we propose a toxic mechanism of action for CTX, involving the interaction of N-terminal region of CB with the target before CA dissociation.
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Affiliation(s)
- Carlos A. H. Fernandes
- Departamento de Física e Biofísica, Instituto de Biociências, Universidade Estadual Paulista, UNESP, Botucatu-SP, Brazil
| | - Wallance M. Pazin
- Departamento de Física, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, USP, Ribeirão Preto-SP, Brazil
| | - Thiago R. Dreyer
- Departamento de Física e Biofísica, Instituto de Biociências, Universidade Estadual Paulista, UNESP, Botucatu-SP, Brazil
| | - Renata N. Bicev
- Departamento de Física Experimental, Instituto de Física, Universidade de São Paulo – USP, São Paulo, SP, Brazil
| | - Walter L. G. Cavalcante
- Departamento de Física e Biofísica, Instituto de Biociências, Universidade Estadual Paulista, UNESP, Botucatu-SP, Brazil
- Departamento de Farmacologia, Instituto de Ciências Biológicas, UFMG, Belo Horizonte, MG, Brazil
| | - Consuelo L. Fortes-Dias
- Diretoria de Pesquisa e Desenvolvimento, Fundação Ezequiel Dias (FUNED), Belo Horizonte, MG, Brazil
| | - Amando S. Ito
- Departamento de Física, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, USP, Ribeirão Preto-SP, Brazil
| | - Cristiano L. P. Oliveira
- Departamento de Física Experimental, Instituto de Física, Universidade de São Paulo – USP, São Paulo, SP, Brazil
| | - Roberto Morato Fernandez
- Departamento de Física e Biofísica, Instituto de Biociências, Universidade Estadual Paulista, UNESP, Botucatu-SP, Brazil
| | - Marcos R. M. Fontes
- Departamento de Física e Biofísica, Instituto de Biociências, Universidade Estadual Paulista, UNESP, Botucatu-SP, Brazil
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Faure G, Porowinska D, Saul F. Crotoxin from Crotalus durissus terrificus and Crotoxin-Related Proteins: Structure and Function Relationship. TOXINS AND DRUG DISCOVERY 2017. [DOI: 10.1007/978-94-007-6452-1_7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Almeida J, Resende L, Silva A, Ribeiro R, Stábeli R, Soares A, Calderon L, Marangoni S, Da Silva S. Biochemical and functional studies of ColTx-I, a new myotoxic phospholipase A2 isolated from Crotalus oreganus lutosus (Great Basin rattlesnake) snake venom. Toxicon 2016; 117:1-12. [DOI: 10.1016/j.toxicon.2016.03.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 03/05/2016] [Accepted: 03/15/2016] [Indexed: 01/13/2023]
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