ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
We present comprehensive 3D lattice Monte Carlo simulations of the folding kinetics of two-turn antiparallel β sheets. The model employed takes into account isotropic nonspecific interactions as in previous flexible heteropolymer models and also orientation-dependent monomer–monomer interactions, mimicking the formation of hydrogen bonds and chain rigidity. The chain length is varied from N=15 to 33. For each chain length, we calculate the fastest folding temperature, Tfast, folding temperature, Tfold, and glass-transition temperature, Tg. The time-averaged occupation probability of the native state is found to be nearly independent of N at all temperatures. The dependence of Tfast and Tfold on N is accordingly relatively weak. The temperature interval where the folding is fast rapidly decreases with increasing N. For the chain lengths chosen, Tfold slightly exceeds Tg. The dependence of the folding time τf on N is well fitted by using the power law, τf∝Nλ. The exponent λ is found to depend on temperature and on the distribution of nonspecific interactions in the chain. In particular, λ=2.7–4.0 at T=Tfast and 5.2 at T slightly below Tfold. Evaluating τf in real units at T near Tfold yields physically reasonable results. © 2000 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.481915
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