beta sheet


Also found in: Dictionary, Thesaurus, Encyclopedia, Wikipedia.
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 ?
Appropriately designed artificial proteins," Tirrell says, "represent a new class of macromolecular materials, with properties potentially quite different from those of the synthetic polymers currently available and in widespread use." For instance, from a carefully designed artificial gene sequence, Tirrell has successfully synthesized a layered crystal made up of stacked beta sheets.
That stickiness is characteristic of all proteins that form neuron-killing beta sheets and may account for the speed at which plaques and other aggregates form.
There are two types of arrangement for secondary structures: the alpha-helix and beta sheets. In the alpha helix there is hydrogen bonding between the hydrogen on the nitrogen and the oxygen on the carbonyl carbon within the same sheet.
The Dow Chemical Company (Midland, MI) has patented a method for inserting Mucin peptide epitopes into the coat protein of a plant virus (e.g., a comovirus such as CPMV) having a beta-barrel structure at an immunogenically effective site, such as in a loop connecting beta sheets or at/near the C-terminus.
According to detailed X-ray analyses (4, 5), the 11 beta sheets that make up the barrel-shaped exterior of the GFP molecule are arranged helically around the barrel axis, with the barrel length somewhat greater than the diameter.
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. Erickson, in collaboration with Jane and David Richardson of Duke University in Durham, N.C., devised a sequence of amino acids that comprises a structure far more regular than any "beta barrels" seen in nature.