Circular dichroism studies of type III collagen mimetic peptides with anti- or pro-aggregant activities on human platelets.

We report the synthesis of collagen related peptides containing the peptide sequence Lys-Hyp-Gly-Glu-Hyp-Gly-Pro-Lys. The anti-thrombotic activity effects of different glycine mutations in this sequence were studied in regard with their different adopted conformations. The biological results could be correlated to the glycine propensity to adopt a more stable polyproline II helix conformation. The incorporation of these sequences in “collagen-like” α-triple-helix peptides shows a pro-thrombotic activity compared to a scrambled negative control peptide which possesses no significant activity.