Your browser doesn't support javascript.
loading
Tryptophan in the pore of the mechanosensitive channel MscS: assessment of pore conformations by fluorescence spectroscopy.
Rasmussen, Tim; Edwards, Michelle D; Black, Susan S; Rasmussen, Akiko; Miller, Samantha; Booth, Ian R.
Afiliação
  • Rasmussen T; School of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, Scotland, United Kingdom. t.rasmussen@abdn.ac.uk
J Biol Chem ; 285(8): 5377-84, 2010 Feb 19.
Article em En | MEDLINE | ID: mdl-20037156
Structural changes in channel proteins give critical insights required for understanding the gating transitions that underpin function. Tryptophan (Trp) is uniquely sensitive to its environment and can be used as a reporter of conformational changes. Here, we have used site-directed Trp insertion within the pore helices of the small mechanosensitive channel protein, MscS, to monitor conformational transitions. We show that Trp can be inserted in place of Leu at the two pore seal positions, Leu(105) and Leu(109), resulting in functional channels. Using Trp(105) as a probe, we demonstrate that the A106V mutation causes a modified conformation in the purified channel protein consistent with a more open state in solution. Moreover, we show that solubilized MscS changes to a more open conformation in the presence of phospholipids or their lysoforms.
Assuntos

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Triptofano / Proteínas de Escherichia coli / Canais Iônicos Idioma: En Revista: J Biol Chem Ano de publicação: 2010 Tipo de documento: Article País de afiliação: Reino Unido

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Triptofano / Proteínas de Escherichia coli / Canais Iônicos Idioma: En Revista: J Biol Chem Ano de publicação: 2010 Tipo de documento: Article País de afiliação: Reino Unido