The effect of extraction, animal age and post mortem storage on tendon collagen. A differential scanning calorimetric study

Summary Differential scanning calorimetry was used to study the collagen → denatured collagen transition in tendon collagen. It was found that purification of collagen by salt (KCI) and trypsin caused a slight, but significant, decrease in the transition temperature, but no significant change in the enthalpy, ΔH D , of the transition. Animal age (0‐6 years) had no significant effect on either ΔH D (mean value = 1293 ± 72 cal. amino acid residue −1 ) or the extrapolated onset temperature, T 0 , (334.2 ± 0.3°K) of the transition in untreated tendon. However, the amount of collagen melting after 340°K increased markedly with age (from 0 to about 250 mg/g of tendon) although the amount melting before 340°K was approximately constant, 138 ± 17 mg/g tendon. Upon storage at 1 ± 1°C for 2 weeks 7 out of 16 tendons became less stable as judged by decreases in T 0 and increases in the amount of collagen melting before 340°K. Two of the tendons became more stable as judged by increases in T 0 and decreases in the amount melting before 340°K. These results are briefly discussed.