Contribution of positively charged flanking residues to the insertion of transmembrane helices into the endoplasmic reticulum
2008 (English)In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 105, no 11, 4127-4132 p.Article in journal (Refereed) Published
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.
Place, publisher, year, edition, pages
2008. Vol. 105, no 11, 4127-4132 p.
membrane protein, positive inside rule, hydrophobicity scale, translocon
Biochemistry and Molecular Biology
IdentifiersURN: urn:nbn:se:su:diva-14922DOI: 10.1073/pnas.0711580105ISI: 000254263300012PubMedID: 18326626OAI: oai:DiVA.org:su-14922DiVA: diva2:181442