ISSN:
0006-3525
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
In this paper a microscopic model is developed which considers conformational changes in polypeptides. The model applied here to diglycine involves calculation of torques due to pairwise interatomic forces acting about the two single bonds (N—C and C—C′) of the peptide unit. Account is taken of Brownian motion and rotational frictional resistance in addition to a van der Waals 6-12 potential, a classical electrostatic potential and a torsional potential. The rates of the conformational transition from an initial α-helical position are computed. The mechanism of Conformational change is a random walk within the minimum well followed by a jump out of the minimum into another portion of the energy surface. The latter process occurs when a fluctuation carries the dipeptide into a high energy region of the potential surface. Correlation times for the process are computed. Estimates are made for the relaxation times for the process. A first passage-time treatment is developed and used to compute internal diffusion coefficients for the relaxation process.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bip.360100604
