Down - Calorimetry

Question 1

[Calorimetry] How is Differential Scanning Calorimetry done and what informatoin does it give us?

Answer 1

Measure the difference in temperature/heat exchange in two cells continously. Based on melting taking energy from temperature increase - visualized as peak in differential curve (alot of heat taken up but no T increase).

Info: Intrinsic (stability and structure) + some interactions

Question 2

[Calorimetry] What equation can be used to get deltaH and deltaS from DSC?

Answer 2

van’t Hoff
- K can be retrieved from unfolded/native ratio, based on the integral of the integrated curve.
- Plot ln K against 1/T, deltaH ~ slope, deltaS ~ intersection

Question 3

[Calorimetry] With DSC, how will the differential curve differ between separate protein and (a) fusion protein and (b) complex?

Answer 3

(a) Denaturation of one part may influence the other - melting point in between individual.

(b) Proteins/molecules stabilize each other - higher melting point.

Question 4

[Calorimetry] How is Isothermal Titration Calorimetry done and what information does it give us?

Answer 4

Label-free method based on heat flow. Compare how much heat needs to be added/removed in the two cells to maintain a constant temperature (one cell with added ligand). Inject and measure the heat change - with more, less change until no change (saturation).

Info: Molecular interactions