β -Pleated Sheets

1. In this inter molecular hydrogen bonds are present
2. Two or more polypeptide chains come together and from a sheet.
3. Condensation in little. However twisting does occur.
4. The same polypeptide may fold over itself to form two strands for b -pleating.
5. Adjacent polypeptide chains may occur in parallel (e.g., b -keratin) or antiparallel (e.g., silk fibroin).
6. Cross-linkages help in stabilization of b -pleated sheets.
7. Protein of secondary structure maintains gel state of protoplasm.
8. Silk protein (Fibroin) is an example of b-Pleated sheets.
9. Lineus pauling got Nobel prize in 1954 for study of a-helix & b-pleated structures of proteins.