Cardiac muscle myosin heavy chain 7 (MYH7) (MYH7)

Cardiac muscle myosin heavy chain 7 (MYH7), specifically its motor domain, is the primary molecular motor responsible for ventricular contraction in the human heart. It functions as an ATPase that converts chemical energy from ATP hydrolysis into mechanical force through interaction with actin filaments in the sarcomere [UniProt P12883]. The motor domain is a critical therapeutic target because its activity is often dysregulated in genetic cardiomyopathies; for instance, hypercontractility and impaired relaxation in hypertrophic cardiomyopathy (HCM) are frequently driven by MYH7 mutations [PubMed: 31534225]. Modern pharmacological interventions target this domain allosterically: inhibitors like Mavacamten stabilize the myosin in a "super-relaxed" state to reduce excessive force, while activators like Omecamtiv mecarbil increase the duration of the power stroke to treat heart failure [PubMed: 32493730]. Managing this target requires careful monitoring of cardiac function to avoid over-suppression of contractility, which can lead to heart failure [FDA: Camzyos Label]. This target represents a shift toward precision medicine in cardiology by addressing the underlying mechanical defect of the sarcomere rather than secondary symptoms.

Other names

Beta-myosin heavy chainMyosin-7Cardiac myosin heavy chain betaMyosin heavy chain 7Slow-twitch skeletal muscle myosin heavy chain

Allosteric modulation of the myosin motor domain to either inhibit (negative inotropy) or activate (positive inotropy) the power stroke and cross-bridge cycling.