Protein Structure

1
Protein Structure
2
Protein Databases

• Protein Data Bank
• http//www.rcsb.org/pdb/Welcome.do
• Select the entries called "2hbs" and "1hab
• Save .pdb files
• Rasmol application
• http//www.umass.edu/microbio/rasmol/getras.htm
• Normal hemoglobin 1hab.pdb
• Sickle cell mutated hemoglobin 2hbs.pdb
• What does normal hemoglobin look like?
• Swapping an A for a T in the gene for hemoglobin
  results in the insertion of valine instead of
  glutamine in the protein molecule causing the
  disease sickle cell anemia.
• What do you think happens in sickle cell?

3
Hemoglobin Attaches to Itself

• Valine is a hydrophobic ("afraid of water") amino
  acid
• Valine-6 is now a kind of "sticky patch" on the
  outside of the hemoglobin
• Valine-6 interacts with a phenylalanine and a
  leucine from another hemoglobin molecule
• This causes the association of 2 individual
  hemoglobin molecules
• Phenyalanine and leucine are both very
  hydrophobic
• http//gingi.uchicago.edu/sc-tour1.html