Deciphering Spectroscopic Signatures of Competing Ca²⁺ - Peptide Interactions.

ABSTRACT: Calcium-protein interactions are of paramount importance in biochemistry. They are a key element in a number of biological processes, such as neuronal signaling. Therefore, an understanding of the interaction at the molecular level is highly desirable. Here, we study the zwitterionic model peptide l-alanyl-l-alanine (2Ala), which has two distinct and competing binding sites for Ca²⁺: The carbonyl of the peptide bond and the C-terminus, the carboxylate group. We perform linear and two-dimensional IR spectroscopy experiments and find that the spectroscopic signatures of both moieties in the IR spectra change in amplitude and peak position upon the addition of CaCl₂: A blueshift of the asymmetric carboxylate band and a redshift for the amide I mode. Ab init

SUBMITTER: Krevert CS 

PROVIDER: S-EPMC11533179 | biostudies-literature | 2024 Oct

REPOSITORIES: biostudies-literature