蛋白质水凝胶在脱水变性过程中裂纹产生的研究  

Study on the Cracking of Protein Hydrogel during Dehydration Denaturation

作　　者：雷婷[1] 张晓媛[1] 张丽[1,2] 周恒为[1,2] 

机构地区：[1]伊犁师范学院物理科学与技术学院新疆凝聚态相变与微结构实验室,新疆伊宁835000 [2]南京大学物理学院国家固体微结构重点实验室,江苏南京210093

出　　处：《伊犁师范学院学报（自然科学版）》2013年第3期31-35,共5页Journal of Yili Normal University：Natural Science Edition

基　　金：中国科学院"西部之光"人才培养计划(RCPY 200906);新疆凝聚态相变与微结构实验室2010年开放课题(XJDX0912-2010-01)

摘　　要：通过液态簧振动力学谱和光学显微镜相结合的方法,在定温、定压和近似定湿度的条件下,同时测量了天然、典型的蛋白质水凝胶——鸡蛋清脱水变性过程的力学谱和显微图像.结果进一步验证了鸡蛋清脱水变性过程依次存在类体水为主的蛋白质水凝胶态(键合水的比例较小)、键合水为主的蛋白质水凝胶态(类体水的比例较小)、键合水和键合蛋白质的混合态、键合蛋白质态等4个状态.其中前2个状态水含量较高,而且水含量变化较大.在键合水和键合蛋白质的混合态中,一定的特征时间处样品中开始产生裂纹.裂纹首先由边缘处产生,且裂纹近似垂直于样品边界,然后向中心辐射发展,最后再产生近似垂直于辐射线的新裂纹.值得指出的是,据笔者所知,这是首次在蛋白质水凝胶脱水变性过程中观测到裂纹产生.本文的工作对深入研究蛋白质变性以及裂纹产生机理无疑有参考价值.The mechanical spectra and microscopic pictures of egg white, a natural and typical protein hydrogel, during of dehydration denaturation were measured by a combination way of the reed-vibration mechanical spectroscopy for liquids and optical microscope under conditions of constant temperature, constant pressure and approximate constant humidity. The results show further that, during the dehydration denaturation of egg white, there are 4 consequent states, i.e. the bulk-like water protein hydrogel state （smaller proportion of bond water）, bond water protein hydrogel state （smaller proportion to bulk-like water）, bond water and protein mixed state, bonding protein state. Water content of the first two states is higher and changes largely. Cracks start to create in the samples of the bond water and protein mixed state at a characteristic time, and they first appear at the edges of samples and their directions are approximately perpendicular to the sample boundaries. Then, the cracks develop into the center of samples in a radialized manner, and a new cracks generate with crack directions perpendicular to the radialized lines at the end times. It is worthy to point out that this is the first time to observe the cracking in protein hydrogel during dehydration denaturation according to the author＇s knowledge. The present work would have reference values on the deep studies of protein denaturation and the crack generation mechanisms.

关 键 词：蛋白质水凝胶 蛋白质变性 力学谱 裂纹 

分 类 号：O552.6[理学—热学与物质分子运动论]