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.

[From beta-form, the form taken by a protein molecule after it has been stretched.]
References in periodicals archive ?
The amyloid-[beta] fibrils have a common parallel, in-register stacking organization based on the beta-pleated sheet stacking of the amyloid-[beta] peptide [16, 23-26].
[2] Amyloidosis, either primary or secondary, is defined as a group of chronic infiltrative disorders that have in common a beta-pleated sheet configuration visualized on X-ray diffraction, a fine fibrillar nonbranching appearance on electron microscopy, and an apple-green birefringence when examined under polarized light after staining with Congo red.
These appeared throughout the samples and often appeared directly adjacent to large [beta]-pleated sheets, however it is unclear whether these structures merged to form the beta-pleated sheet or whether the fibrils were products of the large sheet of peptide.
The pathologic features of amyloid deposits include beta-pleated sheet structures that are composed of amyloid fibrils with diameters between 8 to 10 nm.
There are 12 of these regions in one Notch protein, each containing three beta-pleated sheets. Each EGF repeat contains one two-stranded beta-pleated sheet.
Amyloidosis is not a single disease entity but a spectrum of diseases that have in common the extracellular deposition of insoluble protein fibrils in tissue or organs in a beta-pleated sheet configuration.
(16-18) Identification of amyloid is based on three criteria: (1) Congo red binding and green birefringence under polarized light, (19) (2) a fibril structure on electro microscopy, (20) and (3) confirmation of the characteristic cross beta-pleated sheet on x-ray crystallography and infrared spectroscopy.
The most common secondary structures are the alpha helix and the ribbon-like beta-pleated sheet (see top diagram, p.346).
Sections stained with Congo red dye demonstrated the characteristic yellow and apple-green birefringence, and the lesion had the beta-pleated sheet structure and antiparallel conformation by low-angle x-ray diffraction, typical of amyloidosis.
In brief, amyloid protein deposits are composed of abnormally folded serum amyloid P, glycosaminoglycans, and fibril proteins which fold into characteristic beta-pleated sheets. These abnormal protein deposits are insoluble, resistant to macrophage mediated degradation, and result in organ failure due to anatomic disruption of normal tissue function and organ blood supply.