摘要
为揭示大分子拥挤剂葡聚糖-70(dextran-70)对蛋白质构象和微环境的影响,利用紫外光谱、荧光光谱、同步荧光、荧光量子产率及微流变等技术手段,研究葡聚糖-70添加后溶菌酶(Lys)、牛血清白蛋白(BSA)、β-乳球蛋白(BLG)微观构象的变化。结果表明,添加葡聚糖-70会改变蛋白,尤其是BLG蛋白的三级结构;葡聚糖-70引起蛋白质氨基酸微环境的变化,使蛋白质更趋向于疏水环境;荧光光谱显示,葡聚糖-70会导致蛋白质内源性荧光的猝灭,同时色氨酸和酪氨酸残基移向更加疏水的环境;葡聚糖-70对蛋白质量子产率的影响较小,对Lys的影响更为明显;微流变结果显示,随着葡聚糖-70浓度的增加,混合体系的复数模量和复数粘度增加、蛋白质分子运动速度减慢,可能是蛋白质与葡聚糖-70之间的相互作用所致。本研究结果可为蛋白质和多糖类食品体系的结构设计提供技术支持。
This study aimed to observe the influence of crowding agent dextran-70 on the protein molecules conformation and its residue micro-environment modification.Thus,ultraviolet spectroscopy,fluorescence spectroscopy with various modes,including synchronous,quantum yield,and micro-rheology were used.Lysozyme(Lys),bovine serum albumin(BSA)andβ-lactoglobulin(BLG)were selected as a model protein molecule.The results showed that the presence of dextran-70 induced the ternary structures of protein molecules,and BLG had the most significant change among the three protein molecules.It partially derived from the micro-environmental modification of amino acid residues in protein molecules.In details,fluorescence spectroscopy assessments exhibited that the endogenous fluorescent protein chromophores were quenched,and both the tryptophan residues and the tyrosine residues moved to a more hydrophobic micro-environment with the presence of dextran-70.While this crowding agent presence in solutions had less effect on the quantum yields of protein molecules compared with other assessment features,especially upon Lys with the least influence among all testing protein molecules.Based on micro-rheology assessments,the complex modulus and the complex viscosity of the blending solution prepared by protein molecules with the crowding agent increased with detran-70 concentration.In addition,the motion of protein molecules in solutions also decelerated,which may be attributed to the interactions between protein molecules and dextran-70 molecules.This study provided more knowledge about the structure design and control upon food products made by polysaccharide and protein.
作者
牛付阁
廖华斌
顾斐娜
高一
李哲
曹晏任
周娱
潘伟春
NIU Fuge;LIAO Huabin;GU Feina;GAO Yi;LI Zhe;CAO Yanren ZHOU Yu;PAN Weichun(The School of Food Science and Biotechnology,Zhejiang Gongshang University,Hangzhou,Zhejiang 310018)
出处
《核农学报》
CAS
CSCD
北大核心
2024年第11期2174-2182,共9页
Journal of Nuclear Agricultural Sciences
基金
浙江省自然科学基金项目(LY22C200009)
国家自然科学基金项目(31701650)
浙江工商大学2023年校级科研创新项目(YBXM2023075)。
关键词
蛋白质
多糖
大分子拥挤试剂
相互作用
proteins
polysaccharide
macromolecular crowding agents
interaction
