液态簧振动力学谱在蛋白质水凝胶-脂肪溶胶复合体系脱水变性的应用研究

Application of Reed-vibration Mechanical Spectroscopy for Liquids on Studying Dehydration Denaturation of Protein Hydrogel-fat sol

本课题组首次用液态簧振动力学谱(RMS-L)方法对天然蛋白质水凝胶鸡蛋清的脱水过程进行了测量与分析,初步表明该方法对蛋白质变性检测是可行、有效的.进一步用RMS-L对天然蛋白质水凝胶(protein hydrogel)-脂肪溶胶(fat sol)复合体系(这里简称为PH-FS)鸡蛋黄的脱水变性过程进行了测量与分析.结果表明,随含水量的降低,PH-FS至少存在4个力学谱的显著变化过程.基于此结果并结合相关分析,推测随含水量的降低,PH-FS至少依次存在下述4个状态:(1)I-状态,类体水的PH-FS态;(2)II-状态,键合水的PH-FS态;(3)III-状态,键合水和键合蛋白质以及脂肪颗粒的混合态;(4)IV-状态,键合蛋白质-脂肪颗粒凝聚态.蛋白质的空间构型(spatial configuration)转变即变性,主要发生在拥有键合水的蛋白质通过失水向键合蛋白质转变的混合态.这表明RMS-L对鸡蛋黄脱水变性过程的检测是有效的,即进一步验证了RMS-L对蛋白质脱水变性过程检测的有效性.

In this paper, RMS-L was further applied to measure the dehydration process of egg yolk, a natural protein hydrogel-fat sol （PH-FS） complex system. The results show that there are at least 4 remarkable processes of mechanical spectra with water content. Based on the experiments and relevant analyses, the authors inferred that the reduction of water content, egg yolk at least has the following four states successively： （l） l-state, i.e. bulk-like water PH-FS state; （2） II-state, i.e. bond water PH-FS state; 3） llI-state, i.e. a mixed state of bond water and bonding proteins as well as fat grains; （4） IV-state, i.e. a condensed state of bonding proteins and fat grains, and the spatial configuration change of proteins, namely degeneration, mainly happens in the mixed state in which the proteins with bond water transforms to binding protein by losing the water. This means that the detection of RMS-L to the dehydration denaturation of egg yolk is effective, namely the effectiveness of RMS-L in detecting the dehydration denaturation of protein hydrogels is further verified. The conclusions would also have reference values on the deep studies of protein denaturation mechanisms and protein hydrogel states.