Premium
Matrix formulation of the transition from a statistical coil to an intramolecular antiparallel β sheet
Author(s) -
Mattice Wayne L.,
Scheraga Harold A.
Publication year - 1984
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.360230907
Subject(s) - antiparallel (mathematics) , intramolecular force , chemistry , beta sheet , degree of polymerization , crystallography , sequence (biology) , matrix (chemical analysis) , polymer , polymerization , stereochemistry , protein structure , physics , organic chemistry , biochemistry , chromatography , quantum mechanics , magnetic field
A tractible matrix formulation is developed for the formation of intramolecular antiparallel β sheets in a homopolymer chain molecule. The formulation is applicable to chains with a finite degree of polymerization. It can readily be extended to treat specific‐sequence heteropolymers. Individual sheets may contain any number of strands, the number of residues per strand can range upward from two, and there is no artificial constraint linking the numbers of residues in adjacent strands. The weighting scheme utilizes two end‐effect parameters, denoted by τ and δ. The first parameter is associated with each residue that does not have a partner in a proceding strand, and the latter is associated with each β bend. A third parameter, t , is associated with every residue in the sheet. Conditions are described which lead to the formation of different types of sheets: (1) “sheets” comprised of isolated extended strands; (2) cross‐β fibers in which a sheet contains a large number of very short strands; (3) fibers in which a few very long strands run parallel to the fiber axis; (4) sheets comprised of several strands in which the average strand contains five residues. The fourth type of sheet resembles those found in globular proteins. It is formed when τ and δ are both small, with the ratio, τ/δ, being slightly less than one.