Cardiac beta-myosin heavy chain (β-MHC (or MYH7, the gene name))

Cardiac beta-myosin heavy chain (β-MHC) is a **motor protein and the major contractile protein of the thick filaments in cardiac muscle**, encoded by the MYH7 gene[2][3][4]. It is expressed predominantly in ventricular muscle and to a lesser extent in slow-twitch (type I) skeletal fibers[2][4]. The β-MHC molecule consists of a globular head with ATPase activity (responsible for actin binding and force generation), a neck region that binds regulatory and essential light chains, and a long coiled-coil tail that enables dimerization and formation of thick filaments[1][4][7]. This protein converts chemical energy from ATP hydrolysis into mechanical work and is critical for **sustained, energy-efficient contraction of the heart**, enabling effective blood flow[1][2][4]. β-MHC is genetically and functionally implicated in a range of **cardiovascular diseases**. Mutations in MYH7 are a major cause of hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM), with different mutations leading to varying clinical phenotypes and severities, including risk of heart failure and sudden cardiac death[3][5][6]. Drugs such as **mavacamten** (a myosin inhibitor for HCM) and **omecamtiv mecarbil** (a myosin activator) interact directly with cardiac β-myosin heavy chain to alter cardiac contractility, underscoring its status as a **therapeutic target**[3][5]. Monitoring of β-MHC mutations is an important **biomarker** for genetic cardiomyopathies. Overall, cardiac beta-myosin heavy chain is essential for heart contractile function, a principal molecular marker of inherited heart muscle diseases, and a pharmacological target of emerging therapies for heart failure and cardiomyopathy[2][3][5].

Other names

beta-myosin heavy chainβ-cardiac myosin heavy chainβ-MHCMyHC-βMyosin-7cardiac myosin heavy chain 7ventriclar myosin heavy chain

Inhibition of myosin ATPase activity (mavacamten); Activation of myosin contractility (omecamtiv mecarbil)