HD exchange and PLIMSTEX determine the affinities and order of binding of Ca2+ with troponin C.

ABSTRACT: Troponin C (TnC), present in all striated muscle, is the Ca(2+)-activated trigger that initiates myocyte contraction. The binding of Ca(2+) to TnC initiates a cascade of conformational changes involving the constituent proteins of the thin filament. The functional properties of TnC and its ability to bind Ca(2+) have significant regulatory influence on the contractile reaction of muscle. Changes in TnC may also correlate with cardiac and various other muscle-related diseases. We report here the implementation of the PLIMSTEX strategy (protein ligand interaction by mass spectrometry, titration, and H/D exchange) to elucidate the binding affinity of TnC with Ca(2+) and, more importantly, to determine the order of Ca(2+) binding of the four EF hands of the protein. The four equilibrium consta

SUBMITTER: Huang RY 

PROVIDER: S-EPMC3115450 | biostudies-literature | 2011 Jun

REPOSITORIES: biostudies-literature