• Fulltext

       

        Click here to view fulltext PDF


      Permanent link:
      https://www.ias.ac.in/article/fulltext/jbsc/034/02/0239-0250

    • Keywords

       

      Amphipathic helical peptides; average hydrophobicity; hydrophobic moment; ; membrane-permeabilisation; model membranes

    • Abstract

       

      We investigated the interaction of six 18-residue peptides derived from amphipathic helical segments of globular proteins with model membranes. The net charge of the peptides at neutral pH varies from –1 to +6. Circular dichroism spectra indicate that peptides with a high net positive charge tend to fold into a helical conformation in the presence of negatively charged lipid vesicles. In helical conformation, their average hydrophobic moment and hydrophobicity would render them surface-active. The composition of amino acids on the polar face of the helix in the peptides is considerably different. The peptides show variations in their ability to permeabilise zwitterionic and anionic lipid vesicles. Whereas increased net positive charge favours greater permeabilisation, the distribution of charged residues in the polar face also plays a role in determining membrane activity. The distribution of amino acids in the polar face of the helix in the peptides that were investigated do not fall into the canonical classes described. Amphipathic helices, which are part of proteins, with a pattern of amino acid distribution different from those observed in class L, A and others, could help in providing newer insights into peptide–membrane interactions.

    • Author Affiliations

       

      Chandrasekaran Sivakamasundari1 Ramakrishnan Nagaraj1

      1. Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research (CSIR), Uppal Road, Hyderabad 500 007, India
    • Dates

       
  • Journal of Biosciences | News

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2017-2019 Indian Academy of Sciences, Bengaluru.