Scleroprotein Scleroprotein Scleroproteins or fibrous proteins constitute one of the three main types of proteins (alongside globular and membrane proteins). There are many scleroprotein superfamilies including keratin, collagen, elastin, and fibroin. The roles of such proteins include protection and support, forming connective tissue, tendons, bone matrices, and muscle fiber. A scleroprotein forms long protein filaments, which are shaped like rods or wires. Scleroproteins are structural proteins or storage proteins that are typically inert and water-insoluble. A scleroprotein occurs as an aggregate due to hydrophobic side chains that protrude from the molecule. A scleroprotein's peptide sequence often has limited residues with repeats;
Myosin head although some forms have a globular region in their C-terminal. There are many cell-specific isoforms of myosin heavy chains, coded for by a multi-gene family. Myosin interacts with actin to convert chemical energy, in the form of ATP, to mechanical energy. The 3-D structure of the head portion of myosin has been determined and a model for actin-myosin complex has been constructed. The globular head is well conserved, and is key to contraction. Muscle contraction results from an attachment–detachment cycle between the myosin heads extending from myosin filaments and the sites on actin filaments. The myosin head first attaches to