Cis-trans-Amide isomerism of the 3,4-dehydroproline residue, the 'unpuckered' proline.

ABSTRACT: Proline (Pro) is an outstanding amino acid in various biochemical and physicochemical perspectives, especially when considering the cis-trans isomerism of the peptidyl-Pro amide bond. Elucidation of the roles of Pro in chemical or biological systems and engineering of its features can be addressed with various Pro analogues. Here we report an experimental work investigating the basic physicochemical properties of two Pro analogues which possess a 3,4-double bond: 3,4-dehydroproline and 4-trifluoromethyl-3,4-dehydroproline. Both indicate a flat pyrroline ring in their crystal structures, in agreement with previous theoretical calculations. In solution, the peptide mimics exhibit an almost unchanged equilibrium of the trans/cis ratios compared to that of Pro and 4-trifluoromethylproline deri

SUBMITTER: Kubyshkin V 

PROVIDER: S-EPMC4901939 | biostudies-literature | 2016

REPOSITORIES: biostudies-literature