Beta Sheet

The beta sheet, (β-sheet) (also β-pleated sheet) is a common

motif Motif may refer to: General concepts * Motif (chess composition), an element of a move in the consideration of its purpose * Motif (folkloristics), a recurring element that creates recognizable patterns in folklore and folk-art traditions * Moti ...

of the regular

protein secondary structure Protein secondary structure is the three dimensional form of ''local segments'' of proteins. The two most common secondary structural elements are alpha helices and beta sheets, though beta turns and omega loops occur as well. Secondary struct ...

. Beta sheets consist of beta strands (β-strands) connected laterally by at least two or three backbone

hydrogen bond In chemistry, a hydrogen bond (or H-bond) is a primarily electrostatic force of attraction between a hydrogen (H) atom which is covalently bound to a more electronegative "donor" atom or group (Dn), and another electronegative atom bearing ...

s, forming a generally twisted, pleated sheet. A β-strand is a stretch of

polypeptide Peptides (, ) are short chains of amino acids linked by peptide bonds. Long chains of amino acids are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides ...

chain typically 3 to 10

amino acid Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha ...

s long with backbone in an extended conformation. The supramolecular association of β-sheets has been implicated in the formation of the fibrils and

protein aggregates In molecular biology, protein aggregation is a phenomenon in which intrinsically-disordered or mis-folded proteins aggregate (i.e., accumulate and clump together) either intra- or extracellularly. Protein aggregates have been implicated in a wi ...

observed in

amyloidosis Amyloidosis is a group of diseases in which abnormal proteins, known as amyloid fibrils, build up in tissue. There are several non-specific and vague signs and symptoms associated with amyloidosis. These include fatigue, peripheral edema, weig ...

, notably