Contribution of positively charged flanking residues to the insertion of transmembrane helices into the endoplasmic reticulum.
Proc Natl Acad Sci U S A
; 105(11): 4127-32, 2008 Mar 18.
Article
em En
| MEDLINE
| ID: mdl-18326626
ABSTRACT
Positively charged residues located near the cytoplasmic end of hydrophobic segments in membrane proteins promote membrane insertion and formation of transmembrane alpha-helices. A quantitative understanding of this effect has been lacking, however. Here, using an in vitro transcription-translation system to study the insertion of model hydrophobic segments into dog pancreatic rough microsomes, we show that a single Lys or Arg residue typically contributes approximately -0.5 kcal/mol to the apparent free energy of membrane insertion (DeltaG(app)) when placed near the cytoplasmic end of a hydrophobic segment and that stretches of 3-6 Lys residues can contribute significantly to DeltaG(app) from a distance of up to approximately 13 residues away.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Membrana Celular
/
Retículo Endoplasmático
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article