PHRD5025 Biochem - Lecture 3 Protein Stability Function Diseases

  1. covalent interactions stabilizing protein structure
    disulfide bonds (Cys-Cys)
  2. non-covalent interactions stabilizing protein structure
    • - H-bonds
    • - hydrophobic interactions
    • - electrostatics
    • - ion pairs
    • - van der Waals
  3. type of mutations that generally trigger diseases
    non-conservative mutations
  4. helix breaker
  5. bone diseases caused by
    mutations in collagen
  6. stabilizes cell membrane of muscle cells against mechanical forces associated with muscle contraction
  7. amino acid often part of Image Upload 1-helices
    Ala (highest helix propensity)
  8. increases the non-functional unfolded population
    decreased stability
  9. N state
    functional, native (folded) state
  10. U state
    non-functional, unfolded state
  11. disease caused by the single deletion of Phe at position 508 of a chloride channel
    cystic fibrosis
  12. does the deletion of F508 in CFTR affect protein function?
    no, it just slows down the folding, resulting in a net degradation and decrease in [protein]
  13. 2 steps of peptide synthesis
    • 1) transcription (DNA -> mRNA)
    • 2) translation (mRNA -> amino acid sequence)
  14. 3 competing pathways for a polypeptide
    • 1) folding (to a functional protein)
    • 2) aggregation (exposed hydrophobic residues)
    • 3) degradation (proteases target poorly folded proteins)
  15. reactions always proceed in the direction in which the entropy of the system ____.
  16. major contribution of H-bonds and electrostatic interactions to protein structure
    reducing the energetic cost of having unpaired polar or charged groups in the hydrophobic interior
  17. major contribution of hydrophobic interactions in a protein structure
    increasing the entropy of the solvent
  18. hydrophilic bond that cannot be buried in the protein interior
    peptide bond
  19. disorder that is due to a nonsense mutation in the gene encoding Image Upload 2 chains of Hb (resulting in severe anemia)

    *no Image Upload 3 chain -> no Hb
  20. disease due to a frameshift mutation resulting in insufficient activity of the enzyme hexoaminidase A (enzyme that breaks down the FA derivatives, gangliosides)
    Tay-Sachs disease (aka GM2 gangliosidosis)
  21. most important protein physical parameter that is behind most disease-causing single amino acid mutations
    protein stability
Card Set
PHRD5025 Biochem - Lecture 3 Protein Stability Function Diseases
Protein Stability Function Diseases