Protein structure and folding

Protein structure and folding

1. Folding proteins make them functional

2. Shape and function go hand in hand

3. Primary structure

   • Sequence of aminoacids
     • Aminoacids are the building blocks of proteins
       • Are held together by peptide bonds to form polypeptide chains
         • Proteins are made from one or more polyptide chains

4. Secondary structure

   • Folding
     • Alpha helix (a-helix)
     • Beta-pleated sheet (B-pleated sheet)
     • Depends on the aminoacid arrangement
     • Hydrogen bonds (aminoacid structure)

5. Tertiary structure

   • 3D shape functional folding
   • R-groups (side groups)
     • Can define the aminoacid
     • All involving the R-groups can influence the folding
       • Ionic bonds
       • Hydrogen bonds
       • Disulfide bonds (bridges)
       • Van Der Waals Interactions

6. Quaternary structure

   • Protein consisting of more than 1 polypetide chain
   • Not all proteins
   • Interactions between them (disulfide and hydrogen bonds) can keep them together

7. Chaperonins

   • Help proteins to fold
   • Proteins go into them, chaperonins tend to have an ideal environment for protein folding

8. There are many diseases related protein misfolding (Parkinson, Huntington)

9. Each protein has an ideal environment for functioning (temperature, ph)

   • If the protein is exposed to something outside the ideal environment, it can denature the protein, disrupt the interactions and shape, preventing it from functioning correctly