beta sheet

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beta sheet

n.
A secondary structure that occurs in many proteins and consists of two or more parallel adjacent polypeptide chains arranged in such a way that hydrogen bonds can form between the chains. Also called beta pleated sheet, pleated sheet.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.

beta sheet

A protein configuration resulting from the alignment of multiple adjacent beta strands and formation of hydrogen bonds between them. The beta sheet is a major secondary protein structure motif elucidated by Pauling and Corey, which consists of polypeptide chains in sheets laid side-by-side and are almost completely extended, with an axial distance of 35 nm vs an axial distance of 15 nm in the helix. The PS is stabilised by hydrogen bonds between NH and CO groups of different polypeptide strands; adjacent molecules may run in the same direction (parallel) or in the opposite (antiparallel) direction—e.g., silk fibroin. The PS is a tertiary structure elucidated by X-ray crystallography and seen by EM; it can be produced experimentally by treating Bence-Jones proteins with enzymes, and is a structure typical of amyloidosis. The PS may be seen by the Congo red stain with polarising light to reveal the characteristic apple-green birefringence.
 
EM
Extracellular 700–1000 nm in diameter, fine complex non-branching fibrils.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.

beta sheet

A protein structure in which parallel layers of linked peptides are folded across each other. This structure is characteristic of amyloid proteins.
See also: sheet
Medical Dictionary, © 2009 Farlex and Partners
References in periodicals archive ?
Furthermore, the diagonal peaks associated with beta-sheet become significantly broader and there is an increase in signal near the 1650 [cm.sup.-1] region, a part of the spectrum associated with helical and random-coil conformations, suggesting that OPP induces disorder within the secondary structure of the amyloids and therefore prevents the formation of beta-fibrils.
(a) Predicted secondary structure of [XynA.sub.MG1]; purple box: alpha-helix; green arrow: beta-sheet. (b, c) Three-dimensional representation of [XynA.sub.MG1] with alpha-helices, beta-sheets, and loops folded into the typical [([beta]/[alpha]).sub.8] TIM-barrel structure; (b) top view; (c) side view.
The area crucially important for PB1 interaction with PA (FLKV, 4-7 residues), according to the results of the modeling, was located in a beta-sheet, in contrast to the data presented in [5], where these residues were located in an alpha-helix.
Seki, "Dynamic programming algorithms and grammatical modeling for protein beta-sheet prediction," Journal of Computational Biology, vol.
But apparently the proteins never switch to the beta-sheet formation, so the little clumps aren't toxic to cells in the test tube.
Reversion of prion protein conformational changes by synthetic beta-sheet breaker peptides.
The Jekyll and Hyde change involves abnormal folding of the molecules, which leads to increased amounts of a damaging type of protein structure called "beta-sheet".The breakthrough centres on a peptide - a protein component - that blocks beta-sheet formation.
We separated Amide I band using the procedure previously reported [14] and calculated the signal ratio of beta-sheet and alpha-helix.
Cebe, "Determining beta-sheet crystallinity in fibrous proteins by thermal analysis and infrared spectroscopy," Macromolecules, vol.
"Mononuclear leukocytes seem to offer a stable medium to determine Beta-sheet structure levels as a function of disease development.
Researchers at the Massachusetts Institute of Technology's (MIT's) Center for Materials Science and Engineering say the key to silk's pound-for-pound toughness, which exceeds that of steel, is its beta-sheet crystals, the nano-sized cross-linking domains that hold the material together.