NMR and Protein folding Flashcards
In a 2D NMR spectra of a protein, would poor signal dispersion suggest protein was folded or unfolded?
Unfolded, many residues in a similar environment
Scalar coupling suggests nuclei are connected: through space or through bonds?
Through bonds
Scalar coupling occurring between two nuclei produces 1 or 2 mini peaks occurring on each peak?
2
Dipolar coupling occurring between two nuclei produces 1 or 2 mini peaks occurring on each peak?
1
What was being measured in Anfinsen’s experiment?
Protein folding
What protein was used in Anfinsen’s experiment?
RNase A (Degrades RNA_
Which denaturants were used in Anfinsen’s experiment?
Urea and mercaptoethanol
Why is there very little difference in delta G in a folded nd unfolded protein?
Allows dynamism of protein for: cellular signalling, fast turnover, enzyme reactions etc
How long does a protein take to fold?
A second (roughly)
What are the 3 classical protein folding mechanisms?
Framework model, Hydrophobic collapse model, and nucleation condensation model
What is the premise of the Framework model of protein folding?
Secondary structures form independently (framework) and then attach together
What is the premise of the hydrophobic collapse model of protein folding?
A hydrophobic core is initially formed, then secondary and tertiary structure forms
What is the premise of the nucleation condensation model of protein folding?
A ‘nucleus’ forms initially, this then helps to form the rest of the protein
What is a trigger factor?
A form of chaperone, binds to protein as it leaves ribosome and forms a protective cavity
What are amyloid fibrils usually made from?
Beta strands
