Trends for isolated amino acids and dipeptides: Conformation, divalent ion binding, and remarkable similarity of binding to calcium and lead.

ABSTRACT: We derive structural and binding energy trends for twenty amino acids, their dipeptides, and their interactions with the divalent cations Ca²⁺, Ba²⁺, Sr²⁺, Cd²⁺, Pb²⁺, and Hg²⁺. The underlying data set consists of more than 45,000 first-principles predicted conformers with relative energies up to ~4 eV (~400 kJ/mol). We show that only very few distinct backbone structures of isolated amino acids and their dipeptides emerge as lowest-energy conformers. The isolated amino acids predominantly adopt structures that involve an acidic proton shared between the carboxy and amino function. Dipeptides adopt one of two intramolecular-hydrogen bonded conformations C₅ or . Upon complexation with a divalent cation, the accessi

SUBMITTER: Ropo M 

PROVIDER: S-EPMC5093913 | biostudies-literature | 2016 Nov

REPOSITORIES: biostudies-literature