Myosin Cardiac Muscle

AT

1-2 Weeks

15

Cardiac myosin protein has been purified from bovine heart muscle. The full length myosin protein has been purified with its essential light chains (ELC) and regulatory light chains (RLC), see Figure 1 and 2. Cardiac myosin has been determined to be biologically active in an F-actin activated ATPase assay, but it is not recommended for use in motility assays because of auto-inhibition (Protease digests with alpha-chymotrypsin and papain may create a subfragment that has F-actin moving properties. Cardiac myosin protein is supplied as a white lyophilized powder.When reconstituted in nanopure water, the protein will be in the following buffer: 100
mM Imidizole pH 7.5, 2.4 M KCl, 0.2 mM DTT, 5% sucrose and 1% dextran. The lyophilized protein is stable at 4C desiccated (<10% humidity) for 1 year.

Figure 1. Diagrammatic representation of the myosin II protein and its subfragments. Myosin II or conventional myosin is a hexameric protein consisting of two heavy chains and two light chains. Myosin II can be proteolytically cleaved into heavy meromyosin (HMM, Cat.# MH01) and light meromyosin (LMM) by ?-chymotrypsin. Heavy meromyosin consists of the myosin head subfragment-1 domain (S1), its associated light chains (essential light chains and regulatory light chains), and the coiled-coil subfragment -2 domain. Light meromyosin consists of coiledcoil protein structure. The myosin S1-subfragment is produced by papain digestion of HMM.