兔皮胶原蛋白的微观结构及不同因素对其聚集特性的影响

摘要

以免皮胶原蛋白为原料,通过紫外光谱(UV)、红外光谱(FTIR)和扫描电镜(SEM)对兔皮胶原蛋白的微观结构进行了初步研究,在该基础上进一步研究了温度、胶原蛋白浓度、pH值和离子强度对其聚集特性的影响.紫外光谱和红外光谱的峰型及对应波长均符合工型胶原蛋白的特征,电镜扫描观察到兔皮胶原蛋白为不规则的致密片状膜,部分表面褶皱;聚集特性研究表明,胶原蛋白浓度与测定温度升高,胶原蛋白的聚集速度和聚集程度均增加;在酸性环境中,胶原蛋白聚集时间较长;pH由7增至8的过程中,胶原蛋白的聚集程度先增加后降低,在pH 7.2时,聚集程度和速度均最高;随着离子浓度的增加,聚集程度和聚集速度先增加后降低,在NaCl浓度为120 mmol/L时聚集速度最快,且自组装程度最高.%In this study,UV spectroscopy,Fourier transform infrared spectroscopy and scanning electron microscopy,were used to study the microstructure of rabbit-skin collagen,respectively.The effects of temperature,collagen concentration,pH value and ionic strength on aggregation properties of collage were also studied.The results of UV spectroscopy and Fourier transform infrared spectroscopy showed that the absorption peak and the corresponding wavelength in accordance with the characteristics of type Ⅰ collagen.Moreover,the results of scanning electron microscopy showed that the collagen was irregular dense sheet film,partially wrinkled on the surface.Furthermore,the results of aggregation properties of rabbit-skin collagen indicated that with the increase of temperature and collagen concentration,the aggregation speed of collagen accelerated and the degree of aggregation increased.In acidic environment,the aggregation time was relatively long.When pH increased from 7 to 8,the degree of self-assembly increased first and then decreased.The degree and the speed of self-assembly were the highest at pH 7.2.With the increase of ion concentration,the aggregation rate first increased and then decreased.The collagen reached the fastest aggregation speed and the highest degree of self-assembly in 120 mmol/L NaC1 solution.