Beta-sheet

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 A Beta sheet is a Protein structure which was developed by Linus Pauling and Robert Corey in 1951. The name Beta was chosen, as it was their second proposed structure (the Alpha helix being the first).[1]

Structure

The Beta pleated sheet's structure is very different to the structure of the alpha helix; a Beta sheet is made up of two or more polypeptide chains called Beta strands. These polypeptide strands are almost completely extended, rather than coiled tightly as in the alpha helix.

The side chains on each of the amino acids that form the protein point in opposite directions. A sheet is formed by linking two or more Beta strands adjacent to each other by hydrogen bonds. Adjacent chains can run in either opposite directions, forming an antiparallel Beta sheet, or in the same direction, forming a parallel Beta sheet.[2]

Anti-parallel arrangement

 

References

  1. Berg J.M., Tymoczko J.L., Stryer L. Biochemistry - 6th edition (2008):40
  2. Berg J.M., Tymoczko J.L., Stryer L. Biochemistry - 6th edition (2008):42