Rafael J Borges1, Fábio F Cardoso1, Carlos A H Fernandes1, Thiago R Dreyer1, Delkia S de Moraes2, Rafael S Floriano2, Léa Rodrigues-Simioni2, Marcos R M Fontes3. 1. Departamento de Física e Biofísica, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Rua Prof. Dr. Antonio Celso Wagner Zanin, s/n, 18618-689 Botucatu, SP, Brazil. 2. Departamento de Farmacologia, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Rua Tessália Vieira de Camargo, 126, 13083-862 Campinas, SP, Brazil. 3. Departamento de Física e Biofísica, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Rua Prof. Dr. Antonio Celso Wagner Zanin, s/n, 18618-689 Botucatu, SP, Brazil. Electronic address: fontes@ibb.unesp.br.
Abstract
BACKGROUND: One of the main challenges in snakebite envenomation treatment is the development of stable, versatile and efficient anti-venom therapies. Local myotoxicity in accidents involving snakes from the Bothrops genus is still a consequence of serum therapy inefficient neutralization that may lead to permanent sequelae in their victims. One of the classes of toxins that participate in muscle necrosis is the PLA2-like proteins. The aim of this work was to investigate the role of zinc ions in the inhibition of PLA2-like proteins and to advance the current knowledge of their action mechanism. METHODS: Myographic and electrophysiological techniques were used to evaluate the inhibitory effect of zinc ions, isothermal titration calorimetry assays were used to measure the affinity between zinc ions and the toxin and X-ray crystallography was used to reveal details of this interaction. RESULTS: We demonstrated that zinc ions can effectively inhibit the toxin by the interaction with two different sites, which are related to two different mechanism of inhibition: preventing membrane disruption and impairing the toxin state transition. Furthermore, structural study presented here included an additional step in the current myotoxic mechanism improving the comprehension of the allosteric transition that PLA2-like proteins undergo to exert their function. CONCLUSIONS: Our findings show that zinc ions are inhibitors of PLA2-like proteins and suggest two different mechanisms of inhibition for these ions. GENERAL SIGNIFICANCE: Zinc is a new candidate that can assist in anti-venom treatments and can promote the design of new and even more accurate structure-based inhibitors for PLA2-like proteins. Copyright Â
BACKGROUND: One of the main challenges in snakebite envenomation treatment is the development of stable, versatile and efficient anti-venom therapies. Local myotoxicity in accidents involving snakes from the Bothrops genus is still a consequence of serum therapy inefficient neutralization that may lead to permanent sequelae in their victims. One of the classes of toxins that participate in muscle necrosis is the PLA2-like proteins. The aim of this work was to investigate the role of zinc ions in the inhibition of PLA2-like proteins and to advance the current knowledge of their action mechanism. METHODS: Myographic and electrophysiological techniques were used to evaluate the inhibitory effect of zinc ions, isothermal titration calorimetry assays were used to measure the affinity between zinc ions and the toxin and X-ray crystallography was used to reveal details of this interaction. RESULTS: We demonstrated that zinc ions can effectively inhibit the toxin by the interaction with two different sites, which are related to two different mechanism of inhibition: preventing membrane disruption and impairing the toxin state transition. Furthermore, structural study presented here included an additional step in the current myotoxic mechanism improving the comprehension of the allosteric transition that PLA2-like proteins undergo to exert their function. CONCLUSIONS: Our findings show that zinc ions are inhibitors of PLA2-like proteins and suggest two different mechanisms of inhibition for these ions. GENERAL SIGNIFICANCE: Zinc is a new candidate that can assist in anti-venom treatments and can promote the design of new and even more accurate structure-based inhibitors for PLA2-like proteins. Copyright Â
Authors: Vanessa O Zambelli; Gisele Picolo; Carlos A H Fernandes; Marcos R M Fontes; Yara Cury Journal: Toxins (Basel) Date: 2017-12-19 Impact factor: 4.546
Authors: Guilherme H M Salvador; Thiago R Dreyer; Antoniel A S Gomes; Walter L G Cavalcante; Juliana I Dos Santos; César A Gandin; Mário de Oliveira Neto; Márcia Gallacci; Marcos R M Fontes Journal: Sci Rep Date: 2018-07-09 Impact factor: 4.379
Authors: Guilherme H M Salvador; Fábio Florença Cardoso; Antoniel A Gomes; Walter L G Cavalcante; Márcia Gallacci; Marcos R M Fontes Journal: Sci Rep Date: 2019-01-24 Impact factor: 4.379
Authors: Guilherme H M Salvador; Antoniel A S Gomes; Wendy Bryan-Quirós; Julián Fernández; Matthew R Lewin; José María Gutiérrez; Bruno Lomonte; Marcos R M Fontes Journal: Sci Rep Date: 2019-11-20 Impact factor: 4.379
Authors: Antoniel A S Gomes; Fabio F Cardoso; Maximilia F Souza; Cristiano L P Oliveira; David Perahia; Angelo J Magro; Marcos R M Fontes Journal: Sci Rep Date: 2020-10-01 Impact factor: 4.379