Alpha-keratin keratin cell due to their effect on the various hydrogen bonds in the alpha-keratin network. Alpha-keratins proteins can be one of two types: type I or type II. There are 54 keratin genes in humans, 28 of which code for type I, and 26 for type II. Type I proteins are acidic, meaning they contain more acidic amino acids, such as aspartic acid, while type II proteins are basic, meaning they contain more basic amino acids, such as lysine. This differentiation is especially important in alpha-keratins because in the synthesis of its sub-unit dimer, the coiled coil, one protein coil
Myosin head Myosin head Muscle contraction is caused by the sliding action of thick filaments over thin filaments of the myofibril. Myosin is a major component of thick filaments and most myosin molecules are composed of a head, neck, and tail domain; the myosin head binds to thin filamentous actin, and uses ATP hydrolysis to generate force and "walk" along the thin filament. Myosin exists as a hexamer of two heavy chains, two alkali light chains, and two regulatory light chains. The heavy chain can be subdivided into the globular head at the N-terminal and the coiled-coil rod-like tail at the C-terminal,