黑料网

Abstract

As it is known, the mechanism and properties of transport of the bio-energy hydrolysis of adenosine triphosphate (ATP), are a fundamental problem due to the fact that the many biological processes, such as muscle contraction, DNA reduplication, neuroelectric pulse transfer on the neurolemma and work of calcium pump and sodium pump, and so on, are associated with bioenergy transport through protein molecules. Th erefore, the study of the bioenergy transport along protein molecules has important signifi cance in life science. However, understanding the mechanism of bioenergy transport in protein molecules has been a long-standing problem that remains of great interest today. Davydov proposed a model of bio-energy transport in 1973, in which the coupling between the amide-I vibrarional quantum (exciton ) and the acoustic phonon (molecular displacements) in the amino acid residues results in a nonlinear interaction, which could lead to a self-trapped state of the vibrational quantum. Th e latter plus the deformational amino acid lattice together can travel over macroscopic distances along the molecular chains. However, the lifetime of the Davydov soliton is too small (about 12 13 10 10 sec   ) to be useful in biological processes. Th en it is necessary to reform Davydov?s model, thus many improved models were proposed. We here proposed a new theory of bio-energy transport along protein molecules in living systems based on the changes of structure and conformation of molecules arising from the energy, which is released by ATP hydrolysis. In this theory, a new interaction have been added into the original Hamiltonian. Th e original wave function of the excitation state of single particles have been replaced by a new wave function of two-quanta quasicoherent state. In such a case, bio-energy is carried and transported by the new soliton along protein molecular chains. Th e soliton is formed through self- trapping of two excitons interacting amino acid residues. Th e exciton is generated by vibrations of amide-I (C=O stretching) arising from the energy of hydrolysis of ATP. Th e properties of the soliton are extensively studied by analytical method and its lifetime for a wide ranges of parameter values relevant to protein molecules is calculated using the nonlinear quantum perturbation theory. Th e lifetime of the new soliton at the biological temperature 300K is enough large and belongs to the order of 10 -10 second orτ/τ 0 ≥700. Th e diff erent properties of the new soliton are further studied. Th e results show that the new soliton in the new model is a better carrier of bio-energy transport and it can play an important role in biological processes. Th is model is a candidate of the bio-energy transport mechanism in protein molecules.

Biography

Pang Xiao-feng is a professor, Tutor of Doctors and National excellent scienti fi c worker of China. He is the director of Sichuan key laboratory of Bio- electromagnetism and Electronic technology. He has published more than 150 papers in famous journals in home and abroad and 6 works and 2 text-books