Myosin heavy chain 7 (MYH7) (MYH7)

Myosin heavy chain 7 (MYH7), also known as beta-cardiac myosin, is the primary motor protein in the human heart responsible for converting chemical energy from ATP into mechanical force (UniProt P12883). It functions by forming cyclic cross-bridge interactions with actin filaments, a process that drives myocardial contraction and is strictly regulated by calcium signaling (PubMed: 26843630). In patients with hypertrophic cardiomyopathy (HCM), mutations in MYH7 or associated proteins lead to an excessive number of myosin heads being available for contraction, causing hypercontractility and impaired relaxation (PubMed: 32861202). Mavacamten is a first-in-class small molecule that targets cardiac myosin by binding allosterically and stabilizing the 'super-relaxed' state, which prevents the myosin heads from interacting with actin (FDA Camzyos Label). This mechanism effectively reduces the number of active cross-bridges, thereby decreasing the pathognomonic hypercontractility and improving diastolic filling in HCM (PubMed: 30571475). The term 'Unabsorbed luminal mavacamten' refers to the portion of the drug that remains in the gastrointestinal tract after oral administration and is not a biological target itself (StatPearls: NBK582143).

Other names

Beta-cardiac myosin heavy chainMyosin-7Cardiac muscle myosin heavy chain 7MHC-betaCardiac myosin

Allosteric inhibition of cardiac myosin ATPase, which stabilizes the myosin head in a super-relaxed state and reduces the number of myosin-actin cross-bridges.