Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 1 de 1
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Acta Biochim Biophys Sin (Shanghai) ; 41(10): 858-64, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19779652

RESUMO

As part of continuing studies of the identification of gene organization and cloning of novel alpha-conotoxins, the first alpha4/4-conotoxin identified in a vermivorous Conus species, designated Qc1.2, was originally obtained by cDNA and genomic DNA cloning from Conus quercinus collected in the South China Sea. The predicted mature toxin of Qc1.2 contains 14 amino acid residues with two disulfide bonds (I-III, II-IV connectivity) in a native globular configuration. The mature peptide of Qc1.2 is supposed to contain an N-terminal post-translationally processed pyroglutamate residue and a free carboxyl C-terminus. This peptide was chemically synthesized and refolded for further characterization of its functional properties. The synthetic Qc1.2 has two interconvertible conformations in aqueous solution, which may be due to the cis-trans isomerization of the two successive Pro residues in its first Cys loop. Using the Xenopus oocyte heterologous expression system, Qc1.2 was shown to selectively inhibit both rat neuronal alpha3beta2 and alpha3beta4 subtypes of nicotinic acetylcholine receptors with low potency. A block of about 63% and 37% of the ACh-evoked currents was observed, respectively, and the toxin dissociated rapidly from the receptors. Compared with other characterized alpha-conotoxin members, the unusual structural features in Qc1.2 that confer to its receptor recognition profile are addressed.


Assuntos
Bloqueadores dos Canais de Cálcio/farmacologia , Conotoxinas/farmacologia , Caramujo Conus/química , Peptídeos/farmacologia , Receptores Nicotínicos/metabolismo , Animais , Bloqueadores dos Canais de Cálcio/química , Bloqueadores dos Canais de Cálcio/isolamento & purificação , China , Conotoxinas/síntese química , Conotoxinas/química , Conotoxinas/genética , Conotoxinas/isolamento & purificação , Canal de Potássio Kv1.6/síntese química , Canal de Potássio Kv1.6/farmacologia , Canal de Potássio Kv1.6/fisiologia , Peptídeos/química , Engenharia de Proteínas/métodos , Processamento de Proteína Pós-Traducional
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...