Product Uses Include
- Measurement of F-actin activated ATPase activity
- Identification/characterization of proteins or small molecules that affect heavy meromyosin
ATPase activity
- Identification/characterization of proteins or small molecules that affect heavy meromyosin Factin
interaction
Material
Heavy meromyosin has been produced by α-chymotrypsin proteolytic cleavage of full-length myosin II protein isolated from rabbit skeletal muscle. Heavy meromyosin consists of an active motor fragment consisting of two head domains connected by their subfragment-2 (S2) regions and two pairs of light chains, essential light chain (ELC) and regulatory light chain (RLC), see Figure 1. Heavy meromyosin has been determined to be biologically active in an F-actin activated ATPase assay. Heavy meromyosin is supplied as a white lyophilized powder. When reconstituted in nanopure water, the protein will be in the following buffer: 10 mM Imidizole pH 7.0, 50 mM KCl, 3 mM MgCl2, 1 mM DTT, 5% sucrose and 1% dextran. The lyophilized protein is stable at 4°C desiccated (<10% humidity) for 1 year.
Purity
Protein purity is determined by scanning densitometry of Coomassie Blue stained protein on a 4-20% gradient polyacrylamide gel. Heavy meromyosin protein was determined to be 70% pure.
Biological Activity
The biological activity of rabbit heavy meromyosin is determined from its rate of F-actin activated ATP hydrolysis. A standard biological assay for monitoring ATP hydrolysis by heavy meromyosin consists of an in vitro F-actin ATPase assay (Cat. # bk054). Stringent quality control ensures that in the presence of F-actin, rabbit heavy meromyosin will have a minimum hydrolysis rate 500 fold greater than in the absence of F-actin.
