• Measurement of F-actin-activated cardiac myosin ATPase activity
• Biochemical characterization of cardiac myosin
• Biochemical characterization of cardiac myosin-interacting proteins
• Identification of proteins/small molecules that affect cardiac myosin/F-actin interactions

Cardiac myosin is a specialized motor protein that drives heart muscle contraction by converting chemical energy from ATP into mechanical force. Modulation of cardiac myosin activity is an active area of therapeutic interest.

Native cardiac myosin protein is purified from bovine cardiac muscle. The preparation contains the full-length myosin heavy chain (~200 kDa) along with its associated essential light chains (~25 kDa and ~17 kDa) and regulatory light chains (~20 kDa).

• Formulation: supplied as lyophilized powder
• Composition: when reconstituted to 10 mg/ml, the buffer composition is: 25 mM PIPES pH 7.0, 1.25 M KCl, 1 mM DTT, 2.5% (w/v) sucrose, and 0.5% (w/v) dextran.

Protein purity is assessed by scanning densitometry of Coomassie Blue-stained protein on a4-20% polyacrylamide gel. Purity is determined to be >90% pure.

The biological activity of cardiac myosin is measured by its rate of F-actin–activated ATP hydrolysis. This is assessed using a standard in vitro F-actin ATPase assay. Quality control requires that, in the presence of F-actin, the ATP hydrolysis rate must be at least 10 times greater than in its absence, and the actin-activated ATPase activity must exceed 25 nmol/min/mg of myosin under the experimental conditions (see datasheet).