Biophysical characterization of Vpu from HIV-1 suggests a channel-pore dualism

T. Mehnert, A. Routh, P. J. Judge, Y. H. Lam, D. Fischer, A. Watts, W. B. Fischer

Research output: Contribution to journalArticle

45 Scopus citations

Abstract

Vpu from HIV-1 is an 81 amino acid type I integral membrane protein which consists of a cytoplasmic and a transmembrane (TM) domain. The TM domain is known to alter membrane permeability for ions and substrates when inserted into artificial membranes. Peptides corresponding to the TM domain of Vpu (Vpu 1-32) and mutant peptides (Vpu1-32-W23L, Vpu 1-32-R31V, Vpu1-32-S24L) have been synthesized and reconstituted into artificial lipid bilayers. All peptides show channel activity with a main conductance level of around 20 pS. Vpu1-32-W23L has a considerable flickering pattern in the recordings and longer open times than Vpu1-32. Whilst recordings for Vpu1-32-R31V are almost indistinguishable from those of the WT peptide, recordings for Vpu 1-32-S24L do not exhibit any noticeable channel activity. Recordings of WT peptide and Vpu1-32-W23L indicate Michaelis-Menten behavior when the salt concentration is increased. Both peptide channels follow the Eisenman series I, indicative for a weak ion channel with almost pore like characteristics.

Original languageEnglish (US)
Pages (from-to)1488-1497
Number of pages10
JournalProteins: Structure, Function and Genetics
Volume70
Issue number4
DOIs
StatePublished - Mar 1 2008
Externally publishedYes

Keywords

  • Artificial bilayers
  • Gating
  • HIV-1
  • Ion channels
  • Membrane proteins
  • Vpu

ASJC Scopus subject areas

  • Structural Biology
  • Biochemistry
  • Molecular Biology

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    Mehnert, T., Routh, A., Judge, P. J., Lam, Y. H., Fischer, D., Watts, A., & Fischer, W. B. (2008). Biophysical characterization of Vpu from HIV-1 suggests a channel-pore dualism. Proteins: Structure, Function and Genetics, 70(4), 1488-1497. https://doi.org/10.1002/prot.21642