The kinetics of the thermal denaturation of collagen in unrestrained rat tail tendon determined by differential scanning calorimetry

Miles CA, Burjanadze TV, Bailey AJ · Journal of Molecular Biology

Measures why collagen inside tissue is harder to denature than collagen in solution. The cooperative unit — the stretch of molecule that has to be thermally activated at once — was 26 plus or minus 1 residues in intact fibrils in water but 66 plus or minus 5 in fibrils swollen in acetic acid, and the activation enthalpy rose from 0.518 to 1.306 MJ/mol. Neighbouring molecules in a packed fibril stabilise each other, so a denaturation temperature measured on isolated collagen is a floor for what tissue does, not an estimate of it.

Population

Unrestrained rat tail tendon (no live subjects)

Intervention

Differential scanning calorimetry across heating rates, in water and in acetic acid

Comparator

Intact fibrils in water against swollen fibrils in acetic acid

Limitations

Rat tail tendon, type I, and a physical-chemistry study with no biological or food endpoint. Reports activation kinetics rather than a single denaturation temperature, so it cannot be quoted as a threshold in degrees.