Reorientation of the helix of the tryptophan-rich gp41W peptide from HIV-1 at interfaces

J Chem Phys. 2013 Dec 14;139(22):225105. doi: 10.1063/1.4841795.

Abstract

The glycoprotein gp41 from the Human Immunodeficiency Virus type 1 (HIV-1) has an amino acid sequence enriched in tryptophan residues, the so-called gp41W peptide (i.e., KWASLWNWFNITNWLWYIK) and plays a crucial role in HIV-1 host cell infection. Using the coupling of Second Harmonic Generation targeting the tryptophan residues with lateral surface tension measurements, we investigate the interaction of gp41W with a neat air∕water and a lipid∕water interfaces. At the air∕water interface, gp41W presents a well-defined orientation and this orientation is strongly modified at the lipid∕water interface, depending on the surface pressure. These results show that this strategy is well suited to monitor tryptophan containing α-helices orientation at lipid∕water interfaces.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adsorption
  • Air
  • Amino Acid Sequence
  • HIV Envelope Protein gp41 / chemistry*
  • HIV-1*
  • Kinetics
  • Models, Molecular
  • Molecular Sequence Data
  • Peptide Fragments / chemistry*
  • Phosphatidylglycerols / chemistry
  • Protein Structure, Secondary
  • Tryptophan*
  • Water / chemistry

Substances

  • HIV Envelope Protein gp41
  • Peptide Fragments
  • Phosphatidylglycerols
  • gp41 protein, Human immunodeficiency virus 1
  • Water
  • Tryptophan
  • 1,2-dipalmitoylphosphatidylglycerol