酶法水解乳清分离蛋白制备纳米纤维  

Preparation of Nanofibrils by Enzymatic Hydrolysis of Whey Protein Isolate

作　　者：李璇[1] 单杰[1] 冯志彪[1] 刘春红[1] 李冬梅[1] LI Xuan;SHAN Jie;FENG Zhibiao;LIU Chunhong;LI Dongmei(College of Science, Northeast Agricultural University, Harbin 150030, China)

机构地区：[1]东北农业大学理学院,黑龙江哈尔滨150030

出　　处：《食品科学》2017年第13期118-124,共7页Food Science

基　　金：黑龙江省教育厅面上项目(12531007);黑龙江省青年科学基金项目(QC2010029)

摘　　要：采用天冬氨酸内切酶(Asp endoproteinase,AspN)在37℃诱导乳清分离蛋白(whey protein isolate,WPI)制备蛋白质纳米纤维(protein nanofibrils,PNFs),考察WPI不同水解时间对产物PNFs形貌的影响。利用透射电子显微镜、原子力显微镜、小分子蛋白质十二烷基硫酸钠-聚丙烯酰胺凝胶电泳、硫磺素T荧光、红外光谱以及激光散射法对PNFs及形成过程进行表征。结果显示,该方法制备的产物PNFs呈乳白色,AspN水解得到的5 kD左右的多肽为构筑单元,β-折叠为PNFs稳定存在的主要二级结构,PNFs平均粒径随水解时间延长而增大。酶法制备PNFs解决了酸法中的褐变问题,有望拓展其在食品领域的应用。In the present study,Asp endoproteinase(AspN)was used to induce whey protein isolate(WPI)for preparingprotein nanofibrils(PNFs)at37℃.Transmission electron microscopy(TEM),atomic force microscope(AFM),tricine-SDS-PAGE,thioflavin T fluorescence spectroscopy,infrared spectroscopy and laser scattering were used for thecharacterization of PNFs and its formation process.The results showed that the PNFs was milky white in color,and peptideswith a molecular weight of5kD were the building blocks for PNFs.The major secondary structure in PNFs wasβ-fold,which played a role in its stability,and the average particle size of PNFs was positively proportional to hydrolysis time.Theenzymatic preparation of PNFs,overcoming the problem of browning,is expected to expand its application in food industry.

关 键 词：乳清分离蛋白 天冬氨酸内切酶 蛋白质纳米纤维 多肽 

分 类 号：Q518.4[生物学—生物化学]