Betaplisserte

Betaplisserte, in protein science, refers to beta-pleated sheets, a type of protein secondary structure formed by beta strands aligned side by side and linked by hydrogen bonds between the backbone amide and carbonyl groups. The strands can run in the same direction (parallel sheets) or in opposite directions (antiparallel sheets), producing a sheet-like surface that is often flat but may be twisted.

Beta sheets are composed of extended polypeptide segments, typically ranging from several to a few dozen amino acids. The arrangement creates repeating hydrogen bonds that stabilize the sheet. The sheets can be organized into larger motifs such as beta barrels, beta sandwiches, or beta-alpha-beta units, and they frequently contribute to the rigidity of the protein core.

They occur widely across proteins, from enzymes to structural and binding proteins. The presence and arrangement of beta sheets influence folding pathways, stability, and interaction surfaces. In some cases, extensive beta-sheet content is associated with protein aggregation, as in amyloid fibrils, where misfolded beta strands form cross-beta structures.

Historically, the concept of beta sheets was established in the 1950s by Linus Pauling and Robert Corey as part of the theory of protein secondary structure. Today, beta-pleated sheets are commonly detected by X-ray crystallography and NMR, and predicted by computational methods based on sequence and structural context.