The structure of proteins; two hydrogen-bonded helical configurations of the polypeptide chain.
TLDR
This work has used information about interatomic distances, bond angles, and other configurational parameters to construct two reasonable hydrogen-bonded helical configurations for the polypeptide chain; it is likely that these configurations constitute an important part of the structure of both fibrous and globular proteins, as well as of syntheticpolypeptides.Abstract:
During the past fifteen years we have been attacking the problem of the structure of proteins in several ways. One of these ways is the complete and accurate determination of the crystal structure of amino acids, peptides, and other simple substances related to proteins, in order that information about interatomic distances, bond angles, and other configurational parameters might be obtained that would permit the reliable prediction of reasonable configurations for the polypeptide chain. We have now used this information to construct two reasonable hydrogen-bonded helical configurations for the polypeptide chain; we think that it is likely that these configurations constitute an important part of the structure of both fibrous and globular proteins, as well as of synthetic polypeptides. A letter announcing their discovery was published last year [1].
The problem that we have set ourselves is that of finding all hydrogen-bonded structures for a single polypeptide chain, in which the residues are equivalent (except for the differences in the side chain R). An amino acid residue (other than glycine) has no symmetry elements. The general operation of conversion of one residue of a single chain into a second residue equivalent to the first is accordingly a rotation about an axis accompanied by translation along the axis. Hence the only configurations for a chain compatible with our postulate of equivalence of the residues are helical configurations. For rotational angle 180° the helical configurations may degenerate to a simple chain with all of the principal atoms, C, C' (the carbonyl carbon), N, and O, in the same plane.read more
Citations
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310-Helices in proteins are parahelices
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Strukturbasierte Entwicklung von Protein-Protein-Interaktionsinhibitoren: Stabilisierung und Nachahmung von Peptidliganden
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An introduction to hydrogen bond scalar couplings
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Solid-phase synthesis of short α-helices stabilized by the hydrogen bond surrogate approach
TL;DR: This protocol describes an optimized synthetic strategy for the preparation of stabilized α-helices that feature a carbon-carbon linkage in place of the characteristic N-terminal main-chain hydrogen bond of canonical helices.
References
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Journal ArticleDOI
Two hydrogen-bonded spiral configurations of the polypeptide chain
Linus Pauling,Robert B. Corey +1 more
TL;DR: In this article, two hydrogen-bonded spiral configurations of the polypeptide chain were constructed, with the residues all equivalent, except for variation in the side chain.
Journal ArticleDOI
Nature of the Intramolecular Fold in Alpha-Keratin and Alpha-Myosin
TL;DR: The normal folded configuration a, the extended configuration β, and the reversible intramolecular transformation from a-keratin (or a-myosin) to β-kerATin (or β-myOSin) is the basis of the remarkable long-range elastic properties of this group of protein fibres.