圆二色谱研究胶原模拟多肽三螺旋结构及其热稳定性

发布时间：2018-10-04 18:35

【摘要】：胶原是广泛研究和应用的生物材料,具有独特的三螺旋结构,此结构与其生物学性能密切相关。以胶原模拟多肽(collagen mimetic peptide,CMP)作为胶原的模型分子,通过圆二色谱研究了CMP的三螺旋结构、热稳定性等随序列或长度的改变所发生的规律性变化。根据形成胶原三螺旋结构的重复序列(POG)_n及胶原上α_2β_1整合素识别位点序列GFOGER设计五种不同序列或长度的CMP,采用圆二色谱表征了CMP的三螺旋结构,并通过检测CMP的程序升温变性和程序降温复性过程中圆二色谱的变化,研究了CMP三螺旋结构的热变性过程、解链温度以及复性过程。实验结果显示,五种CMP室温下均以三螺旋结构的形式存在,CMP三螺旋结构的热稳定性随POG的个数增加而增强;不同于胶原,CMP三螺旋结构的热变性是可逆的,升温过程中三螺旋解聚(变性),降温过程又可重新组装(复性),复性过程有明显的"磁滞"现象。研究结果可为进一步研究胶原与CMP分子特征性的三螺旋结构形成规律以及基于CMP的人工类胶原生物材料的研究提供依据。
[Abstract]:Collagen is a widely studied and applied biomaterial, which has a unique triple helix structure, which is closely related to its biological properties. Collagen mimic polypeptide (collagen mimetic peptide,CMP) was used as the model molecule of collagen. The trihelix structure and thermal stability of CMP were studied by circular dichroism. Five kinds of CMP, with different sequences or lengths were designed according to the repeated sequence (POG) n of collagen trihelical structure and the 伪 s 2 尾 1 integrin recognition site GFOGER on collagen. The trihelix structure of CMP was characterized by circular dichroism. The thermal denaturation process, chain dissociation temperature and renaturation process of CMP trihelical structure were studied by detecting the changes of circular dichroism during the programmed denaturation and programmed renaturation of CMP. The experimental results show that the thermal stability of five kinds of CMP in the form of trihelical structure increases with the increase of POG number at room temperature, and the thermal denaturation of POG is reversible. In the process of heating, three helix depolymerization (denaturation), cooling process can be reassembled (renaturation), renaturation process has obvious "hysteresis" phenomenon. The results can provide a basis for the further study of the formation of the trihelix structure of collagen and CMP molecules and the study of artificial collagen biomaterials based on CMP.
【作者单位】：中国医学科学院北京协和医学院生物医学工程研究所天津市生物医学材料重点实验室;福州大学生物和医药技术研究院;
【基金】：国家自然科学基金项目(31170917) 国家科技支撑计划项目(2012BAI7B03)资助
【分类号】：R318.08

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