Poster Presentation 10th Australian Peptide Conference 2013

Synthesis of potent multivalent oxytocin dendrimers via “click” chemistry” (#192)

Jingjing Wan 1 , Mehdi Mobli 2 , Andreas Brust 1 , Irina Vetter 1 , Stuart Brierley 3 , Mathias Nilsson 4 , Richard Lewis 1 , Paul Alewood 1
  1. Institute for Molecular Bioscience, University of Queensland, Brisbane, QLD, Australia
  2. Centre for Advanced Imaging, University of Queensland, Brisbane, QLD, Australia
  3. Discipline of Medicine, University of Adelaide, Adelaide , SA, Australis
  4. School of Chemistry, University of Manchester, Manchester, United Kingdom

Peptide dendrimers as therapeutics have potential use in different biotechnological applications.1 Nevertheless, the efficient conjugation of peptides containing disulfide bonds to a core dendron may be challenging due to the steric hindrance.2,3 In this study we describe the synthesis, structure, functional activity and anti-nociceptive properties of dendrimeric oxytocin (OT) agonists containing one disulfide bond. Dendrimeric peptides with up to 16 copies of OT agonists were successfully synthesised via copper(I)-catalyzed azide-alkyne cycloaddition (CuAAc) reaction based on the biodegradable, alkyne modified, oligolysine dendron and azido-PEG(9)-[Lysine]8-OT. Detailed NMR analysis of the OT dendrimers suggests that each attached OT molecule is identical with negligible structural perturbation as compared to OT in the monomeric form. The motion of OT dendrimers in solution was studied by diffusion ordered spectroscopy (DOSY), indicating that the arms of the dendrimers are disordered allowing each OT monomer to rotate freely about its own axis. Functional activity was demonstrated on human cell lines containing the OTR receptor. Interestingly, the OT dendrimers inhibited colonic nociceptors in a mouse model of chronic abdominal pain.

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