| Abstract: | Effects of heat in heated solution of tropocollagens of different origins were calorimetrically studied. It was found that denaturation enthalpy and entropy of different tropocollagens increase with increasing imino acid content and thermostability. It is shown that the value and dependence of denaturational enthalpy and entropy on the denaturation temperature for tropocollagens with different imino acid contents are inconsistent with the assumption that the native structure of tropocollagen is stabilized only by intramolecular hydrogen bonds. A supposition is made that the regular water structure near the macromolecule plays an essential role in stabilizing the structure. From the character of tropocollagen melting curves in salt-free solution it is found that the tropocollagen macromolecule is linearly heterogeneous. It is shown that the complex pattern of thermal absorption observed in tropocollagen salt, solution is connected with pre-denaturational conformational transformation when approaching conditions close to the physiological. |
