Sionkowska Alina
Faculty of Chemistry, N. Copernicus University, 870100 Torun, Poland.
Int J Biol Macromol. 2005 Apr;35(3-4):145-9. doi: 10.1016/j.ijbiomac.2005.01.009.
The thermal helix-coil transition of UV irradiated collagen in rat tail tendon has been investigated by differential scanning calorimetry. During UVB irradiation the tendons were immersed in water to keep the collagen fibers in a fully hydrated condition at all times. UV irradiation induced changes in collagen which caused both stabilization and destabilization of the triple helix in fibers. The helix-coil transition for non-irradiated collagen occurred near 64 degrees C, for irradiated 1 and 3 h at 66 and 67 degrees C, respectively. After irradiating for longer times (20-66 h) the helix-coil transition peak occurred at much lower temperatures. The peak was very broad and suggested that collagen was reduced by UV to different polypeptides of different molecular weight and different lower thermal stabilities. It was caused by the disruption of a network of hydrogen-bonded water molecules surrounding the collagen macromolecule.
通过差示扫描量热法研究了大鼠尾腱中紫外线照射的胶原蛋白的热螺旋-线圈转变。在UVB照射期间，将肌腱浸入水中，以使胶原纤维始终处于完全水合状态。紫外线照射引起胶原蛋白的变化，导致纤维中三螺旋的稳定和不稳定。未照射的胶原蛋白的螺旋-线圈转变发生在64摄氏度附近，照射1小时和3小时的胶原蛋白分别在66摄氏度和67摄氏度发生转变。照射更长时间（20-66小时）后，螺旋-线圈转变峰出现在低得多的温度下。该峰非常宽，表明紫外线将胶原蛋白还原为不同分子量和不同较低热稳定性的不同多肽。这是由围绕胶原大分子的氢键结合水分子网络的破坏引起的。
