氯化钠对猪肉肌原纤维蛋白构像及其与辣椒素相互作用的影响

Effects of sodium chloride on the configuration of porcine myofibrillar protein and its interaction with capsaicin

中文关键词:  肌原纤维蛋白  辣椒素  氯化钠  相互作用  蛋白质结构

英文关键词:myofibrillar proteins  capsaicin  sodium chloride  interaction  protein structure

中文摘要:

      目的 探究氯化钠浓度对猪肉肌原纤维蛋白(myofibrillar proteins, MPs)与辣椒素(capsaicin, CAP)相互作用的影响。方法 选择0~0.9 mol/L的氯化钠处理MPs, 然后与CAP在25℃进行反应, 并采用粒度仪、十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(sodium dodecyl sulfate-polyacrylamide gel electrophoresis, SDS-PAGE)、激光共聚焦显微拉曼光谱、荧光光谱分析了不同浓度氯化钠对MPs的结构以及MPs与CAP相互作用的影响。结果 MPs在溶液中的稳定性随氯化钠浓度的增加而逐渐增强; SDS-PAGE表明, 氯化钠浓度的改变, 会引起MPs溶液中各种蛋白质分子组成的变化; 氯化钠浓度的升高会增强MPs表面疏水性, 并进一步促进了MPs与CAP的结合。拉曼光谱数据表明氯化钠的存在没有显著改变MPs的二级结构, 同时, CAP与MPs结合不影响MPs的二级结构。荧光猝灭光谱数据表明: 在不同氯化钠浓度下, CAP均能引起MPs的内源荧光产生静态猝灭; 且随着氯化钠浓度的增加, MPs-CAP复合物的结合常数Kb值及n值均增大, 表明氯化钠能够促进MPs与CAP的相互作用。结论 氯化钠浓度的增加能够提高MPs稳定性, 不改变MPs的二级结构, 能够通过增加MPs表面疏水性的方式促进MPs与CAP之间的相互作用。

英文摘要:

      Objective To explore the effects of NaCl concentration on the interaction between porcine myofibrillary proteins (MPS) and capsaicin (CAP). Methods MPs was treated with 0?0.9 mol/L NaCl and reacted with CAP at 25℃, and the configuration of MPs and the interaction of MPs-CAP in the presence of NaCl at different concentrations were investigated using particle size analyzer, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), laser confocal microscopic Raman spectroscopy and fluorescence spectroscopy. Results The stability of MPs in the solution increased with the increased NaCl concentration. SDS-PAGE showed that the change of the NaCl concentration could cause changes in protein molecular compositions in MPs solution. Moreover, the surface hydrophobicity of MPs increased with the increased NaCl concentration, leading to increased interaction between MPs and CAP. Roman spectra revealed that no obvious change was found in the secondary structure of MPs in the presence of NaCl, and the interaction of CAP and MPs did not affect the secondary structure of MPs. Fluorescence date indicated that CAP could quench the fluorescence of MPs through a static process in the presence of NaCl at selected concentrations. The binding constant Kb and number of binding sites n of MPs-CAP complex increased with the increased NaCl concentration, demonstrating that NaCl could increase the interaction between MPs and CAP. Conclusion The increase of NaCl concentration can improve the stability of MPs without changing the secondary structure of MPs, and can promote the interaction between MPs and CAP by increasing the hydrophobicity of MPs surface.