二氢杨梅素对鲢鱼肌球蛋白理化性质及蛋白构象的影响

Effects of dihydromyricetin on the physicochemical properties and protein conformation of myosin in Hypophthalmichthys molitrix

中文关键词:  二氢杨梅素  肌球蛋白  理化性质  蛋白构象

英文关键词:dihydromyricetin  Hypophthalmichthys molitrix  myosin  physicochemical properties  protein conformation

中文摘要:

      目的 探究二氢杨梅素对鲢鱼肌球蛋白理化性质及蛋白构象的影响机制, 以及不同浓度二氢杨梅素对鲢鱼肌球蛋白的作用效果。方法 向鲢鱼肌球蛋白溶液中加入不同浓度的二氢杨梅素储备液, 使溶液中的二氢杨梅素浓度为1×10?5、2×10?5、3×10?5、4×10?5、5×10?5 mol/L, 并设对照组(二氢杨梅素浓度为0 mol/L)。测定蛋白溶解度、浊度、总巯基含量的变化, 检测混合液的傅里叶变换红外光谱、近紫外吸收光谱与内源荧光光谱。结果 鲢鱼肌球蛋白溶液添加二氢杨梅素后的混合液相较于对照组, 蛋白溶解度先升高后降低, 蛋白聚集程度显著提升, 总巯基含量先升高后降低。傅里叶变换红外光谱在1700~1600 cm?1与1600~1500 cm?1两个波长区间出现最高的吸收峰, 峰的位置略有蓝移, 侧链基团受到二氢杨梅素的影响, 二级结构发生改变。内源荧光光谱的最大吸收峰位置发生红移, 近紫外吸收光谱的酪氨酸与色氨酸吸收峰位置略有红移, 三级结构发生改变。综合考虑二氢杨梅素对鲢鱼肌球蛋白理化性质、凝胶特性的影响与添加成本, 二氢杨梅素的最佳添加量为4×10?5 mol/L。结论 添加二氢杨梅素可以改善鲢鱼肌球蛋白的溶解度、聚集程度、疏水性与凝胶特性, 通过其与肌球蛋白相互作用, 进而改变肌球蛋白的蛋白构象。

英文摘要:

      Objective To explore the mechanism of dihydromyricetin on the physicochemical properties and protein conformation of Hypophthalmichthys molitrix myosin, and the effect of different concentrations of dihydromyricetin on Hypophthalmichthys molitrix myosin. Methods Different concentrations of dihydromyricetin stock solution were added to the Hypophthalmichthys molitrix myosin solution, so that the concentration of dihydromyricetin in the solution was 1×10?5, 2×10?5, 3×10?5, 4×10?5, 5×10?5 mol/L, and the control group (the concentration of dihydromyricetin was 0 mol/L) was set up. The changes of protein solubility, turbidity and total sulfhydryl content were determined, and the Fourier transform infrared spectroscopy, near ultraviolet absorption spectroscopy and endogenous fluorescence spectroscopy of the mixture were detected. Results Compared with the control group, the protein solubility of the Hypophthalmichthys molitrix myosin solution after adding dihydromyricetin increased first and then decreased, the degree of protein aggregation increased significantly, the total sulfhydryl content increased first and then decreased. Fourier transform infrared spectroscopy showed the highest absorption peaks in the 2 wavelength ranges of 1700?1600 cm?1 and 1600?1500 cm?1, and the peak position was slightly blue-shifted. The side chain group was affected by dihydromyricetin, and the secondary structure was changed. The position of the maximum absorption peak of the endogenous fluorescence spectrum was red-shifted, and the absorption peaks of tyrosine and tryptophan in the near-ultraviolet absorption spectrum were slightly red-shifted, and the tertiary structure was changed. Considering the effects of dihydromyricetin on the physicochemical properties, gel properties effect and cost, the optimum addition amount of dihydromyricetin was 4×10?5 mol/L. Conclusion The addition of dihydromyricetin can improve the solubility, aggregation degree, hydrophobicity and gel properties of Hypophthalmichthys molitrix myosin, and change the protein conformation of myosin through its interaction with myosin.