Myosin Heavy Chain Antibody, a

Identification and enumeration of myosin heavy chain+ cells by flow cytometryClone REA399 recognizes the human, mouse, and rat cardiac isoform of the myosin heavy chain (MHC) antigen. Myosin forms cross-bridges with actin in cardiac, smooth, and skeletal muscle, and cyclic cross-bridge activity is the basis for muscular contraction. It is a hexamer composed of two heavy chains, each of which contains an actin-binding site and an ATP hydrolysis site, and four light chains. Isoforms of each myosin subunit are expressed in cardiac, skeletal, and smooth muscle, and many are associated with distinct contractile properties in the muscles or single muscle fibers in which they are expressed. In cardiac muscle, two MHC isoforms, termed α-MHC and β-MHC, are present. α-MHC is associated with higher actomyosin ATPase activity compared with β-MHC. The relative amounts of the two isoforms may vary, with the ratio being a function of the hormonal status, the developmental stage, the animal, or the particular region of the heart. | Additional information: Clone REA399 displays negligible binding to Fc receptors.