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Cellular uptake of S413-PV peptide occurs upon conformational changes induced by peptide-membrane interactions

Miguel Mano1, Ana Henriques, Artur Paiva

  • 1Centro de Neurociências e Biologia Celular, Universidade de Coimbra, Portugal.

Biochimica Et Biophysica Acta
|March 7, 2006
PubMed

Insights

The S4(13)-PV peptide efficiently enters live cells via direct membrane translocation, not endocytosis. This process involves conformational changes and is facilitated by cell surface heparan sulfate proteoglycans.

Area of Science:

  • Cell Biology
  • Biochemistry
  • Peptide Science

Background:

  • Cell-penetrating peptides (CPPs) are crucial for drug delivery.
  • Previous studies suggested CPP uptake occurs via endocytosis or fixation artifacts.
  • The uptake mechanism of the S4(13)-PV karyophilic CPP required clarification.

Purpose of the Study:

  • To systematically analyze the cellular uptake mechanism of the S4(13)-PV peptide.
  • To determine if S4(13)-PV uptake occurs through endocytosis.
  • To investigate the role of heparan sulfate proteoglycans and peptide conformation in uptake.

Main Methods:

  • Live cell imaging to observe peptide accumulation.
  • Comparative uptake studies using mutant cells lacking heparan sulfate proteoglycans.
  • Lipid vesicle interaction assays to monitor peptide conformational changes.
  • Spectroscopic analysis to detect structural alterations.

Main Results:

  • S4(13)-PV efficiently accumulates in live cells rapidly, non-toxically, and in a dose-dependent manner.
  • Uptake mechanism is distinct from endocytosis.
  • Heparan sulfate proteoglycans facilitate, but are not mandatory for, uptake.
  • S4(13)-PV undergoes conformational changes (helical structures) upon interaction with lipid bilayers.
  • Conformational changes correlate with peptide penetration into lipid bilayers.

Conclusions:

  • S4(13)-PV cellular uptake occurs via direct membrane translocation, not endocytosis.
  • Conformational changes, leading to helical structures, are critical for non-endocytic uptake.
  • Membrane interactions and peptide structure are key determinants of S4(13)-PV cell penetration.

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