Myosin Light chain [MY-21]

MY-21

Chicken lens membranes.

Myosin Light chain

15mM Sodium Azide

Cytoplasmic Contractile proteins are ubiquitous in eukaryotic cells. Their presence is related to motile functions. The two major cytoskeletal proteins implicated in cell motility are actin and myosin. Numerous investigators have shown that actin and myosin are constituents of many cell types and are involved in a myriad of cellular processes including locomotion secretion cytoplasmic streaming phagocytosis and cytokinesis. Myosin is a 500 000 dalton protein known to interact with identical heavy chains (200 000 daltons each) and four light chains (15 000-20 000 daltons). Myosin molecules consist of two major regions: tail (rod) and head regions. Myosin has three major biological functions:1. Myosin molecules spontaneously assemble into filaments in solutions of physiologic ionic strength and pH. Thick filaments consist mainly of myosin molecules. 2. Myosin is an enzyme (ATPase) and its activity is the immediate source of the free energy that drives muscle contraction. 3. Myosin binds to the polymerized form of actin the major constituent of the thin filament. Myosin can be viewed in immunofluorescent microscopy enabling the delineation of the intracellular organization of proteins that are in the form of a supramolecular structure.

Myosin is an hexamer of 2 heavy chains and 4 light chains.