Structure-activity relationship study of the tumour-targeting peptide A20FMDV2 via modification of Lys16, Leu13, and

Kuo-Yuan Hung1, Paul W R Harris2, Ami Desai3

  • 1School of Biological Sciences, The University of Auckland, 3a Symonds Street, Auckland Central 1010, New Zealand.

Insights

Modified A20FMDV2 peptides show improved stability and activity. These analogues target tumor-associated αvβ6 integrins, enhancing their potential for drug delivery applications.

Area of Science:

  • Biochemistry
  • Peptide Chemistry
  • Drug Delivery

Background:

  • The peptide A20FMDV2 targets the tumor-associated αvβ6 integrin.
  • A20FMDV2 has potential as a drug delivery vector but suffers from poor plasma half-life due to protease susceptibility.

Purpose of the Study:

  • To synthesize and evaluate A20FMDV2 analogues with enhanced plasma stability and maintained αvβ6 integrin binding affinity.
  • To improve the therapeutic potential of A20FMDV2 by increasing its half-life and reducing degradation.

Main Methods:

  • Synthesis of fourteen A20FMDV2 analogues with non-proteinogenic amino acid substitutions (Lys16, Leu13).
  • Synthesis of six A20FMDV2 analogues with modified N- and C-termini.
  • Functionalization of promising analogues with diethylenetriaminepentaacetic acid (DTPA) for radiolabeling with indium-111.
  • In vitro activity assays and plasma stability studies.

Main Results:

  • Analogues with modified terminal motifs retained strong binding to the αvβ6 integrin.
  • A20FMDV2 variants with N-terminal d-Asn and C-terminal d-Thr demonstrated improved in vitro activity.
  • These specific variants exhibited reduced susceptibility to plasma degradation, indicating enhanced stability.

Conclusions:

  • Modification of the N- and C-termini of A20FMDV2 can significantly improve its plasma stability.
  • The developed analogues maintain high affinity for the αvβ6 integrin, preserving their potential as targeted drug delivery vectors.
  • These findings pave the way for more effective peptide-based therapeutics targeting αvβ6 integrin-expressing tumors.