Soliton dynamics in proteins
- Univ. Erlangen-Nuernberg, Erlangen (Germany)
The mechanism for energy and signal transport in proteins is suggested by Davydov is discussed. This mechanism is based on a coupling of amide-I oscillators to acoustic phonons in a hydrogen bonded chain. Results as obtained with the usually used ansaetze are discussed. The quality of these states for an approximate solution of the time-dependent Schroedinger equation is investigated. It is found that the semiclassical ansatz is a poor approximation, while the more sophisticated {vert_bar}D{sub 1}> state seems to represent the exact dynamics quite well. Calculations at a temperature of 300K for one chain, as well as for three coupled ones (as they are present in an {alpha}-helix) are presented and discussed. From the calculations it is evident, that Davydov solitons are stable for reasonable parameter values at 300K only for special initial excitation at one terminal site of the chain, which has to be the one having a C=O group not directly coupled to the lattice. Since the model for temperature effects used was critisized from the theoretical point of view, we suggest an improved theory for temperature effects. Recent experimental findings, that also normal modes describing mainly N-H stretching vibrations are their coupling to the hydrogen bonds, instead of amide-I, should be considered are discussed.
- OSTI ID:
- 447569
- Report Number(s):
- CONF-960343-; TRN: 97:005466
- Resource Relation:
- Conference: 2. international congress on theoretical chemical physics, New Orleans, LA (United States), 9-13 Mar 1996; Other Information: PBD: 1996; Related Information: Is Part Of Second international congress on theoretical chemical physics - ICTCP II; PB: 90 p.
- Country of Publication:
- United States
- Language:
- English
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