This review discusses the structural features, biological significance, detection methods, and biomimetic applications of Polyproline II helices, emphasizing recent advances in characterization techniques and their roles in supramolecular assembly.
The collagen model peptide Ac-(Hyp-Gly-Pro)2-NMe2 with the replacement of Pro3 by azPro in the middle of the sequence well adopted polyproline II structures with RMSD = 0.6 Å in water.
An engineered T67C myoglobin mutant undergoes self-oxidation of Cys67 to a sulfinic acid (Cys–SO2H), as confirmed by the X-ray crystal structure, which provides a useful platform to generate artificial proteins by further chemical modifications.
Introduction of CF3-oxazolidines in polyproline type II foldamers maintains PPII helicity, non-cytotoxicity and stability towards proteolysis. The CF3 groups enhanced hydrophobicity and are used as easy-to-handle 19F NMR probes.
We investigate short peptides and their propensity to form specific secondary structures. We show that the propensity might start to appear in sequences as short as several (3-11) amino acids.