beta sheet


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Related to beta sheet: Beta barrel

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.

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.

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
References in periodicals archive ?
Although five amino acids seem to be enough to form beta sheets, "proteins have to do more than fold," says Baker.
For instance, from a carefully designed artificial gene sequence, Tirrell has successfully synthesized a layered crystal made up of stacked beta sheets.
Also, the experiments used equal parts of the molecule to protein in order to stop the proteins from forming the toxic beta sheets, which may mean that therapies would require massive amounts of the compound to work effectively.
The mollusk proteins probably contain accordion-pleated structures known as beta sheets, but those are much more difficult to synthesize and work with, he says.
Each unit's longest segment contains a nearly identical sequence of 15 amino acids, which arrange into the so-called beta sheets that give the molecule its strength.
Several different proteins, such as immunoglobulins and the enzyme superoxide dismutase, have bell-shaped, slatted regions made up of an arrangement of amino acids called beta sheets.