Extending the Proline Effect: ΨPro for Tailoring cis-trans Isomerisation

Abstract

Pseudo-Prolines (ΨPro) consist of (4S)-oxazolidine- and (4R)-thiazolidine-carboxylic acids derived from amino acids Ser, Thr and Cys. They represent new branched proline analogues in which variation of the substituents (R¹, R², R³) results in different physicochemical and conformational properties. We summarise here the relevant chemical and structural aspects of such super-prolines intended to constrain and control the peptide backbone in β-turn motifs or to alter the imide cis-trans ratio.