BCH210H1 Lecture Notes - Lecture 4: Polyproline Helix, Alpha Helix, Proline

• School: UTSG
• Department: Biochemistry
• Course: BCH210H1
• Professor: Stavroula Andreopoulos

Document Summary

If you put a bunch of prolines together: totally different from alpha helix poly-proline helix no hydrogen bonds holding it together. Composition to sequence to structure to function: fibrous proteins (silk, wool, collagen, structural proteins within cells (cytoskeleton, enzymes (globular proteins, membrane proteins (transporters, channels, receptors) secreted proteins. Residue compositions of fibrous proteins: silk, wool high cysteine very high in glycine and alanine content (disulfide linkages since wool is exposed to oxygen, collagen high in proline and glycine. Fibrous proteins silk: silk has repeating unit gly-ser-gly-ala-gly- ala, conducive to beta-pleated sheets. Inter-chain hydrogen bonds are formed while side chains are above and below the plane of the sheet: gly might be on one side of the chains and ser/ala might be on the other side. Beta-pleated sheet: hydrogen bonds are formed between protein chains, side chains (green) are facing opposite to each other, 1 gly face, 1 ser/ala face.