Investigating tertiary and quaternary structure of proteins

State 3 ways to investigate tertiary and quaternary protein structure

• x-ray crystallography

• nuclear magnetic resonance (NMR)

• cryo electron microscopy

What does x-ray crystallography require?

highly pure and concentrated protein crystal

How would you go about growing a protein crystal?

gently add salt to very pure and concentrated protein to reduce its solubility, this can be done via hanging drop or vapour diffusion

How does x-ray crystallography generate an image? (2 points)

• x-ray beam is fired through protein crystal

• intensity and position of each spot is used to reconstruct an image of the protein

How can x-ray crystallography display 3D electrons

density distribution can be represented by a series of parallel sections stacked on top of each other (contour map)