Portal de Periódicos da CAPES

The Molecular Basis of Muscle Contraction

1983; Wiley; Linguagem: Inglês

10.1002/9780470720752.ch8

1935-4657

Kenneth C. Holmes, Roger S. Goody,

Cardiovascular Effects of Exercise

Muscle contraction takes place by the cyclic interaction of two-stranded helical actin filaments with protuberances from the myosin filaments known as cross-bridges. The nature of the contractile process demands that the myosin cross-bridge be highly polymorphic. Biochemical evidence points to the cross-bridge having a domain structure such that contraction may be a manifestation of the rearrangement of these subunits. An essential step in contraction may be the initial binding of a small hinged domain of the cross-bridge (the 'nose-cone') to actin, followed by a series of changes ending in the formation of a second union (the rigor bond) with an actin monomer in the neighbouring strand of the actin helix.