Chemical Physics Letters, Vol.715, 77-83, 2019
Using a collagen heterotrimer to screen for cation-pi interactions to stabilize triple helices
As one of non-covalent forces to stabilize protein, cation-pi interactions in collagen have been received much attention. Three chains of collagen form its characteristic secondary structure, triple helices. Based on a collagen heterotrimer, abc, a library containing 15 mutant peptides was built to characterize the stabilizing effects of 24 pairwise cation-pi interactions. The six stabilizing pairs, axial FK, YK, WK, RF, and RW, and lateral RF, have been identified, among which only axial RF frequently occurs in natural collagen sequences. This suggests that cation-pi interactions might not be optimized in natural collagen.