Differential scanning calorimetry and x ray diffraction study of tendon collagen thermal denaturation
Bigi, A.; Cojazzi, G.; Roveri, N.; Koch, M.H.J.
International Journal of Biological Macromolecules 9(6): 363-367
ISSN/ISBN: 0141-8130 DOI: 10.1016/0141-8130(87)90010-9
Differential scanning calorimetry, high and small angle X-ray diffraction analyses have been carried out on air-dried and rehydrated rate tail tendon collagen in order to test the reversibility of collagen thermal denaturation. The mean enthalpy values calculated for the denaturation process of air-dried and rehydrated samples are .DELTA.HD = 9.0 .+-. 0.8 cal/g and .DELTA.HD = 11.9 .+-. 0.7 cal/g respectively, while the denaturation temperatures are TD = 112 .+-. 1.degree. C and TD = 51 .+-. 1.degree.C. Partial reversibility of the coiled coil-random coil process can be obtained by storing the samples in air or more rapidly by equilibration in water. After denaturation air-dried collagen fibers recover not only their molecular structure but also their characteristic fibrillar structure. The latter does not greatly influence the mean experimental enthalpy values.