Kinesin belongs to the group of motor proteins known to convert chemical energy released from ATP into mechanical energy. Conventional kinesin, member of the kinesin superfamily comprising more than 100 proteins, is involved in the anterograde vesicle transport inneuronal cells. Kinesin purified from mammalian brain homogenates is a heterotetramer consisting of two heavy (120-130kD) and two light chains (60-70kD), resulting in a molecular mass about 400kD. Each heavy chain contains an N-terminal globular motordomain with both a microtubule-binding site and an ATPase active center, stalk region responsible for heavy chain dimerization and finally C-terminal globular tail domain, which is implicated in cargo binding. Light chains may have a regulatory function.