Helix-Coil, Liquid Crystal, and Spin Glass Transitions of a Collapsed Heteropolymer
Abstract
Using simple statistical mechanical models, we investigate secondary structure formation in the molten globule state of a helix-forming heteropolymer. The theory based on the helix-coil model of Bragg and Zimm correctly treats the one-dimensional aspect of the helix-coil transition but has been modified to include the randomness effects of the tertiary interactions in a heteropolymer. Rough approximations to the effects of confinement, excluded volume, and packing order of the helices are used to give the resulting generalization of the random energy model. In this model the packing effects give rise to a liquid crystalline order in the molten globule state. For reasonable values of parameters at the spin glass transition, we estimate that the heteropolymer is about 80% helical with helix lengths of order 20. Analysis of this simple model allows an estimate of the effective Levinthal entropy and determines that about 10^(11) configurations would have to be searched at the glass transition for a 100-mer.
Additional Information
© 1995 American Chemical Society. Received: July 15, 1994; In Final Form: September 23, 1994. This work was supported by NIH Grant PHS R01 GM44557 to P.G.W. B.E.R. also acknowledges W. A. Goddard and H. B. Gray for facilitating a short visit to the University of Illinois which allowed for the completion of this work. We would like to thank J. D. Bryngelson and K. A. Dill for bringing some references to our attention that we missed in the first draft of the manuscript.Additional details
- Eprint ID
- 86602
- DOI
- 10.1021/j100007a057
- Resolver ID
- CaltechAUTHORS:20180524-154040189
- PHS R01 GM44557
- NIH
- Created
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2018-05-24Created from EPrint's datestamp field
- Updated
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2021-11-15Created from EPrint's last_modified field