CHEM237 Lecture Notes - Lecture 6: Amyloidosis, Fibrinogen, Protein Disulfide-Isomerase

• School: University of Waterloo
• Department: Chemistry
• Course: CHEM237
• Professor: Elisabeth Daub

Document Summary

Now let"s discuss quaternary structure: some proteins naturally aggregate with other proteins, usually for biological activity. These interactions are specific and reproducible and are what form the quaternary structure of proteins: an example of this is hemoglobin, which is the oxygen carrying protein which has an a2b2 structure. If you can rotate a quaternary structure 180 degrees and it"s still the same, it has an axis of symmetry. Transthyretin has an a2 structure: glutamine synthetase has an a12 structure. This is the one that looks like a donut. If you consider an alpha helix, all the hydrophobic residues are on one side of the helix, facing inward. A hydropathy scale is useful for showing a relative measure of hydrophobicity of all the amino acid side chains. They get these values from putting the proteins inside water and try to extract it in the organic phase.