Protein Folding

Who showed that a protein could be refolded using only a protein

Anfinsen

Where is all the necessary information for folding the peptide chain into its native structure contained

In the primary amino acid structure of the peptide

Ribonuclease can be unfolded by treatment with

Urea and β-Mercaptoethanol

Why do proteins fold

To bury hydrophobic residues and expose polar residues

Stable folding maximizes

the number of weak interactions

Exposed polar residues interact with

solvent waters

The ΔG for protein folding is typically

-20 to -40 kJ/mol

Microcalorimetry of protein unfolding indicates a

favorable enthalpy change

Denaturation

Loss of protein structure and function

Chaperones

help proteins fold by preventing innappropriate liaisons in the crowded cellular environment

How to chaperones work

They prevent intermolecular unproductive interactions between hydrophobic sequences

What do chaperones recognize

exposed hydrophobic residues

Proteins of the Hsp70 class bind to

nascent polypeptides