离子浓度对明胶与直链淀粉相互作用的影响

Effect of ionic concentration on the interaction between gelatin and amylose

采用光谱法研究离子浓度对明胶与直链淀粉相互作用的影响。结果表明:离子浓度能改变明胶的疏水微环境;离子浓度不同,直链淀粉对明胶的内源荧光有不同程度猝灭,其机制是以静态猝灭为主的动静结合猝灭;增大离子浓度,明胶与直链淀粉的结合能力增强;在水溶液中,明胶与直链淀粉之间的作用力主要是范德华力和氢键,加入NaCl后,明胶与直链淀粉之间主要通过疏水作用力驱动;明胶与直链淀粉结合引起明胶重排与构象的变化,从而引起酪氨酸和色氨酸残基的变化,且结合位点更接近酪氨酸残基。离子浓度影响明胶与直链淀粉的相互作用,添加适量NaCl有利于明胶与直链淀粉的结合且引起明胶构象的变化。

The effect of ionic concentration on the interaction between gelatin and amylose was investigated by spectroscopic methods. The results showed that ionic concentration could change the hydrophobic microenvironment of gelatin. With different ionic concentration, amylose could quench the endogenous fluorescence of gelatin to different degrees. The quenching mechanism was coupling quenching, which was mainly static quenching. With the increase of ionic concentration, the binding ability of gelatin and amylose was enhanced. In aqueous solution, the forces between gelatin and amylose were mainly van der Waals forces and hydrogen bonds, which were mainly driven by hydrophobic forces after sodium chloride was added. Gelatin-amylose binding caused rearrangement and conformational changes of gelatin, resulting in the change of tyrosine residues and tryptophan residues, and the binding site was closer to the tyrosine residues. The gelatin-amylose interaction was effected by the ionic concentration, the addition of sodium chloride was beneficial to the combination of gelatin and amylose and caused the change of conformation of gelatin.