单宁酸对丝素蛋白二级结构的影响作用研究  

Study on the effect of tannic acid on the secondary structure of silk fibroin protein

作　　者：李炜祥 凌静 王详 吕汪洋[1,2] 孔祥东 LI Weixiang;LING Jing;WANG Xiang;L Wangyang;KONG Xiangdong(School of Materials Science&Engineering,Zhejiang Sci-Tech University,Hangzhou 310018,China;Zhejiang-Mauritius(ZSTU)Joint Research Center for Biomaterials and Tissue Engineering,Hangzhou 310018,China)

机构地区：[1]浙江理工大学材料科学与工程学院,杭州310018 [2]浙江毛里求斯(浙理)生物医用材料与组织工程联合研究中心,杭州310018

出　　处：《丝绸》2023年第6期1-6,共6页Journal of Silk

基　　金：国家自然科学基金项目(51672250);国家现代农业产业技术体系基金项目(CARS-18);浙江省自然科学基金项目(LQ19E020010);浙江省“一带一路”国际科技合作项目(2019C04020)。

摘　　要：蛋白质的二级结构是其发挥生物功能的重要基础结构,因此本文通过单宁酸和丝素蛋白反应,研究不同摩尔浓度的单宁酸对丝素蛋白二级结构的影响。使用紫外可见光吸收光谱(UV-Vis)、荧光发射光谱(FL)和傅里叶红外吸收光谱(FTIR)等表征技术对单宁酸与丝素蛋白的反应产物进行测试,结果表明单宁酸可以影响丝素蛋白的二级构象,并呈现一定的变化趋势。单宁酸摩尔浓度逐渐增加到20μmol/L时,α螺旋和无规卷曲结构逐渐增多,β折叠结构逐渐减少。单宁酸摩尔浓度继续上升,α螺旋和无规卷曲结构逐渐减少,β折叠结构逐渐增多。The secondary structure of proteins is an important basic structure for their biological functions.Studies have shown that the changes of secondary structure in proteins affect their biological reactions to the outside environment,and the spectrum of proteins can reflect their secondary structure changes to a certain extent.Silk fibroin,widely used in scientific research and social life,is an ideal research object.To study the cause and process of secondary structure transformation of silk fibroin,we carried out experiments to explore the effect of tannic acid on the secondary structure of silk fibroin through the reaction between different concentrations of tannic acid and silk fibroin.The reaction of tannic acid and silk fibroin was studied by UV-visible absorption spectrum(UV-Vis),fluorescence emission spectroscopy(FL)and fourier infrared absorption spectroscopy(FTIR),showing that the tannic acid and silk fibroin could be chemically bonded.The UV absorption spectra of the reaction solution of 0-40μmol/L tannic acid and 1 mg/mL silk fibroin solution,and of the 10μmol/L tannic acid solution show that the n-Π*displacement of carbon skeleton C O of silk fibroin polypeptide leads to a strong absorption peak at 230 nm whose intensity decreases gradually with the combination of tannic acid hydroxyl group and silk fibroin.The weak absorption peak at 276 nm represents that theΠ-Π*and n-Π*transitions of aromatic heterocyclic rings in the silk fibroin molecule are weakened by the binding between tryptophan and tannic acid.The redshifts of the two absorption peaks indicate that the polarity of the microenvironment around tryptophan in silk fibroin is strengthened with the increase of tannic acid concentration in the solution.It is found from the fluorescence emission spectra of the reaction solution of 0-40μmol/L tannic acid and 1 mg/mL silk fibroin,and of the 10μmol/L tannic acid solution that the emission peak intensity of tryptophan residues at 352 nm gradually decreases with the increase of tannic acid concent

关 键 词：丝素蛋白 单宁酸 二级结构 氨基酸残基 紫外可见光吸收光谱 荧光发射光谱 傅里叶红外吸收光谱 

分 类 号：TS102.33[轻工技术与工程—纺织工程]