以具有代表性的6个大豆品种制备的大豆7S球蛋白为研究对象,采用ANS荧光探针法测定表面疏水性,Ellman试剂分析法测定巯基和二硫键含量,激光拉曼光谱和荧光光谱分析空间构象,探讨大豆7S球蛋白结构特性与表面疏水性的相关性。结果表明:大豆7S球蛋白的表面疏水性与二级结构的α-螺旋含量和β-折叠含量呈负相关,与二级结构的β-转角含量和无规则卷曲含量呈正相关;与色氨酸残基荧光峰λmax呈正相关,与拉曼光谱色氨酸费米共振I1360/I1340值呈负相关,与拉曼光谱酪氨酸费米共振I850/I830值呈正相关,与暴露的酪氨酸残基克分子数呈正相关,与N暴露和N包埋的比值呈正相关;与暴露巯基含量、巯基暴露程度呈正相关,与游离巯基含量、二硫键含量、二硫键构象的相关性均不显著。
With β- conglycinin (7S) prepared from six representative soybean varieties as raw material, the correlation between the structure characteristics and surface hydrophobicity of 7S was studied. The surface hydrophobicity of 7S was determined by ANS fluorescent probe method, the content of sulfhydryl and disulfide bond was determined by EUman reagent analysis method, and conformation was analyzed by Raman spectroscopy and fluorescence spectroscopy. The results showed that there were negative correlations between surface hydrophobicity and the content of α-helix, β- sheet and Fermi resonance Raman spectra of tryptophan I1360/I1340 ratio. There were positive correlations between surface hydrophobicity and - turn, random coil, λmax of tryptophan residues, Fermi resonance Raman spectra of tryptophan I850/I830 ratio, the number of exposed of exposed sulfhydryl. There tyrosine residues, the value was not correlation between of Nexposure: Nembedding and the the surface hydrophobicity content and degree and the content of free sulfhydryl, the content of disulfide bond and disulfide bond conformation.