1. Protein Structures: Thermodynamic Aspects (1)
PROTEIN PHYSICS
LECTURE 17
Protein Structures: Thermodynamic Aspects (1)
Protein denaturation: reversible, cooperative and,
moreover, “all-or-none” (1-st order) phase transition.
Solid native state, unfolded coil & “molten globule”.

2. Solid structures
However,
solid structures can denaturate (decay) both in vivo (e.g., when protein is transported through membrane) and in vitro

3. Protein denaturation: cooperative transition

4. Denaturation:
“all-or-none”
transition
in small
(one-domain)
proteins

7. Denaturation: “all-or-none” transition
in small (one-domain) proteins
(Privalov, 1969)

9. Solid native state, unfolded coil, “more compact molten state”
and cooperative transitions between them ?
(Tanford, 1968)

10. Secondary structure Side chain packing
un-
folded
native

15. “All-or-none” decay of native protein structure: Ensures reliability
and robustness
of protein functioning