Diversity of Secondary Structure in Catalytic Peptides with β-Turn-Biased Sequences.

ABSTRACT: X-ray crystallography has been applied to the structural analysis of a series of tetrapeptides that were previously assessed for catalytic activity in an atroposelective bromination reaction. Common to the series is a central Pro-Xaa sequence, where Pro is either l- or d-proline, which was chosen to favor nucleation of canonical β-turn secondary structures. Crystallographic analysis of 35 different peptide sequences revealed a range of conformational states. The observed differences appear not only in cases where the Pro-Xaa loop-region is altered, but also when seemingly subtle alterations to the flanking residues are introduced. In many instances, distinct conformers of the same sequence were observed, either as symmetry-independent molecules within the same unit cell or as polymorphs. C

SUBMITTER: Metrano AJ 

PROVIDER: S-EPMC5312972 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature