Composite Conformational Changes of Signaling Proteins upon Ligand Binding Revealed by a Single Approach: Calcium-Calmodulin Study.

ABSTRACT: Signaling proteins exemplified by calmodulin usually bind cooperatively to multiple ligands. Intermediate states and allosteric behavior are difficult to characterize. Here we extend a recently reported mass spectrometry (MS)-based method named LITPOMS (ligand titration, fast photochemical oxidation of proteins and mass spectrometry) that characterizes complex binding systems typically found as signaling proteins. As reported previously, calmodulin's response to binding four Ca²⁺ can be determined by LITPOMS to reveal binding sites, binding order, and most importantly composite binding behavior. Modeling this behavior provides site-specific binding affinities. In this article, we dissect the composite, peptide-level conformational changes at several regions either by digestion w

SUBMITTER: Liu XR 

PROVIDER: S-EPMC7485628 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature