摘要
采用荧光光谱和紫外可见吸收光谱研究了脂质体与卵白蛋白(OVA)相互作用的热力学特征。结果显示,脂质体对OVA的荧光猝灭存在动态和静态两种作用方式。在298K、305K和312K时,脂质体与OVA的结合常数分别为7.631×10^(3) L/mol、3.157×10^(3) L/mol和2.463×10^(3) L/mol,两者结合位点数(n)分别为1.374、1.218和1.164。根据热力学方程求得在298K、305K和312K时,两者相互作用的热力学参数,ΔG分别为-17.264kJ/mol、-17.674kJ/mol和-17.625kJ/mol,ΔS分别为51.967J/(mol·K)、51.612J/(mol·K)和49.835J/(mol·K),ΔH为-1.777kJ/mol,脂质体与OVA相互作用为放热过程,两者之间的主要作用力为氢键和范德华力。脂质体与OVA相互作用改变了蛋白质氨基酸残基所处的微环境,引起OVA的构象变化。
The thermodynamic characteristics of the interaction between liposomes and ovalbumin(OVA)was studied by fluorescence spectroscopy and ultraviolet-visible absorption spectroscopy.The results showed that the endogenous fluorescence of OVA was quenched via dynamic quenching and static quenching.The binding constants between liposomes and OVA were 7.631×103 L/mol at 298K,3.157×103 L/mol at 305K and 2.463×103 L/mol at 312K,respectively.The corresponding numbers of binding sites(n)were 1.374 at 298K,1.218 at 305K and 1.164 at 312K,respectively.According to the thermodynamic equation,thermodynamic parameters of the interaction between liposomes and OVA were obtained.ΔG was-17.264kJ/mol at 298K,-17.674kJ/mol at 305K and-17.625 kJ/mol at 312K,respectively;ΔS was 51.967J/(mol·K)at 298K,51.612J/(mol·K)at 305K and 49.835 J/(mol·K)at 312K;ΔH was-1.777kJ/mol.The main types of interaction forces between liposomes and OVA were hydrogen bond and van der Waals force,and the interaction was exothermic.The interaction between liposome and OVA has changed the microenvironment of protein amino acid residues and caused the conformational change of OVA.
作者
聂丹
丁保淼
NIE Dan;DING Baomiao(School of Life Science,Yangtze University,Jingzhou 434025)
出处
《中国食品添加剂》
CAS
北大核心
2022年第5期11-15,共5页
China Food Additives
基金
国家自然科学基金项目(31972013)。
关键词
脂质体
卵白蛋白
热力学参数
相互作用力
liposome
ovalbumin
thermodynamic parameters
interaction force
