The theory of contraction of proteins under their excitation.

Abstract This paper develops the quantum theory of contraction of α-helical proteins under the excitation of their peptide groups, which form three parallel chains of hydrogen bonds along the molecule. In the region embraced by an excitation, the pitch of the helix decreases, and the “contracted” region of the helix moves along the molecule at a rate proportional to the energy of resonance interaction between peptide groups. The movement of the excitation region from the head of the myosin molecule to its tail results in movement of the myosin filaments along the actin ones in the myofibril of the muscle, and thus leads to a decrease in length of the muscle fibre.