【摘要】 应用Raman光谱分析了不同亚油酸浓度下脂肪氧合酶催化诱导产生的大豆蛋白聚集体的结构变化。结果表明,当模拟反应体系中亚油酸浓度在3.14~6.09 mmol/L范围之间时,拉曼光谱中归属于CH和CH2弯曲振动的谱带强度增强,而归属于位于非极性环境中的色氨酸和酪氨酸残基的谱带强度减弱;当亚油酸浓度达到7.51 mmol/L时,则出现相反的结果,这表明大豆蛋白质的聚集涉及到疏水相互作用。此外,在蛋白质拉曼光谱中还观察到胱氨酸残基二硫键的伸缩振动变化。二级结构分析表明反应后大豆蛋白α-螺旋减少,β-折叠增加。更多还原

【Abstract】 The molecular structure of soybean protein aggregates formed with different linoleic acid concentration catalyzed by lipoxygenase have been examined by Raman spectral analysis. When the linoleic acid concentration in model system between 3. 14 and 6. 09 mmol / L,reacted soybean proteins had an involvement of hydrophobic interactions by intensification of spectral bands assigned to CH & CH2 bending vibrations and decreased in the intensity of bands assigned to tryptophan and tyrosine residued in a nonpolar environment. When the linoleic acid concentration reached 7. 51 mmol / L,the contrary results could be observed in the model system. Changes in the disulphide stretching vibrations of cystine residues also have been observed by Raman spectral analysis. Secondary structure analysis demonstrated that the interacting with linoleic acid catalyzed by lipoxygenase resulted in a decreased proportion ofα- helix structures and increased proportion of β- sheet structures.更多还原