Protein foldning Flashcards
What is the anfinsen experiment and what is the conclusion?
Two experiments:
1. Took a protein reduced it, added urea which denatured the protein. Then they removed the urea and oxidized the protein which then regained its native structure
- Took a protein reduced it, added urea which denatured the protein. Then they oxidized the protein and removed the urea but the protein couldn’t regain it’s native state.
Conclusion: The information in the protein sequence is enough to determine the protein structure.
Which proteins assist in foldning?
PPI, PDI and Chaperones
What does PPI stand for and what does it do?
Peptidyl propyl isomerase catalyzes cis-trans isomerization of propyl-peptide bonds
What does PDI stand for and what does it do?
Protein difulfide isomerase catalyzes the formation of disulfide bond
What are chaperones and how does it assist protein foldning?
Chaperons are heat-shock proteins which are upregulated after heat shock to assist protein folding and are important for correct folding during normal cell conditions.
How does the GroEL/ES system work?
Unfolded protein binds to the GroEL pocket not blocked by GroES and ATP binds to each subunit. ATP hydolysis occurs and GroES gets released along with ADP. GroES binds to the pocket with the protein and the protein folds inside the enclosure. The folded or partially folded protein is then released into the cell.
