Assuntos
Analgésicos/farmacologia , Peptídeos/farmacologia , Anêmonas-do-Mar , Sequência de Aminoácidos , Animais , Animais não Endogâmicos , Modelos Animais de Doenças , Temperatura Alta , Injeções Intraperitoneais , Camundongos , Dados de Sequência Molecular , Dor/tratamento farmacológico , Peptídeos/genética , Proteínas Recombinantes/farmacologia , Anêmonas-do-Mar/genética , Homologia de Sequência de AminoácidosAssuntos
Algoritmos , Conotoxinas/química , Desenho de Fármacos , Antagonistas Nicotínicos/química , Receptor Nicotínico de Acetilcolina alfa7/química , Acetilcolina/farmacologia , Sequência de Aminoácidos , Animais , Aplysia , Conotoxinas/genética , Relação Dose-Resposta a Droga , Humanos , Ligantes , Lymnaea , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Modelos Moleculares , Dados de Sequência Molecular , Agonistas Nicotínicos/farmacologia , Antagonistas Nicotínicos/farmacologia , Oócitos , Xenopus laevis , Receptor Nicotínico de Acetilcolina alfa7/agonistas , Receptor Nicotínico de Acetilcolina alfa7/antagonistas & inibidores , Receptor Nicotínico de Acetilcolina alfa7/metabolismoRESUMO
Using methods of molecular biology we defined the structures of the 31 sea anemone Heteractis crispa genes encoding polypeptides which are structurally homologous to the Kunitz proteinase inhibitor family. Identified amino acid sequences have point residue substitutions, high degree of homology with sequences of known H. crispa Kunitz family members, and represent a combinatorial library of polypeptides. We generated their three-dimensional structures by homologous modeling methods. Analysis of their molecular electrostatic potential enabled us to divide given polypeptides into three clusters. One of them includes polypeptides APHC1, APHC2 and APHC3, which were earlier shown to possess a unique property of inhibiting of the pain vanilloid receptor TRPV1 in vitro and providing the analgesic effects in vivo in addition to their trypsin inhibitory activity. Molecular docking made possible establishing the spatial structure of the complexes, the nature of the polypeptides binding with TRPV1, as well as functionally important structural elements involved in the complex formation. Structural models have enabled us to propose a hypothesis contributing to understanding the APHC1-3 impact mechanism for the pain signals transduction by TRPV1: apparently, there is an increase of the receptor relaxation time resulted in binding of its two chains with the polypeptide molecule, which disrupt the functioning of the TRPV1 and leads to partial inhibition of signal transduction in electrophysiological experiments.