Plant Polypeptide Hormone Systemin Prefers Polyproline II Conformation in Solution.

ABSTRACT: Systemin, an 18 amino-acid-signaling peptide, was the first plant polypeptide hormone to be discovered. Earlier structural studies involving NMR spectroscopy indicated a lack of definite structure in solution while circular dichroism spectroscopy suggested the presence of left-handed polyproline II (PPII) conformation. Here, we report the results of molecular dynamics simulations of the peptide in explicit solvent with two different force fields, namely, ff99SBildn and ff99IDPs, both of which showed a large propensity for PPII-like conformations in spite of showing differing features for other conformational characteristics. More remarkably, the conformations with predicted chemical shifts that agreed better with the NMR observations had a larger than average PPII content, especially for t

SUBMITTER: Dutta Chowdhury S 

PROVIDER: S-EPMC6644842 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature