Free-Energy Surfaces of Two Cardiac Thin Filament Conformational Changes during Muscle Contraction.

ABSTRACT: The troponin core is an important regulatory complex in cardiac sarcomeres. Contraction is initiated by a calcium ion binding to cardiac troponin C (cTnC), initiating a conformational shift within the protein, altering its interactions with cardiac troponin I (cTnI). The change in cTnC-cTnI interactions prompts the C-terminal domain of cTnI to dissociate from actin, allowing tropomyosin to reveal myosin-binding sites on actin. Each of the concerted movements in the cardiac thin filament (CTF) is crucial for allowing the contraction of cardiomyocytes, yet little is known about the free energy associated with each transition, which is vital for understanding contraction on a molecular level. Using metadynamics, we calculated the free-energy surface of two transitions in the CTF: cTnC opening

SUBMITTER: Mason AB 

PROVIDER: S-EPMC9167776 | biostudies-literature | 2022 Jun

REPOSITORIES: biostudies-literature