The Distinct Conformational Landscapes of 4S-Substituted Prolines That Promote an endo Ring Pucker.

ABSTRACT: 4-Substitution on proline directly impacts protein main chain conformational preferences. The structural effects of N-acyl substitution and of 4-substitution were examined by NMR spectroscopy and X-ray crystallography on minimal molecules with a proline 4S-nitrobenzoate. The effects of N-acyl substitution on conformation were attenuated in the 4S-nitrobenzoate context, due to the minimal role of the n→π* interaction in stabilizing extended conformations. By X-ray crystallography, an extended conformation was observed for most molecules. The formyl derivative adopted a δ conformation that is observed at the i+2 position of β-turns. Computational analysis indicated that the structures observed crystallographically represent the inherent conformational preferences of 4S-substituted prolines w

SUBMITTER: Costantini NV 

PROVIDER: S-EPMC6710147 | biostudies-literature | 2019 Aug

REPOSITORIES: biostudies-literature