碱性橙与蛋白间的特异性与非特异性作用荧光光谱比较

将碱性橙与抗体的作用、碱性橙与牛血清白蛋白(BSA)间的作用分别作为特异性作用和非特异性作用模型,采用荧光光谱法固定激发波长为280 nm,扫描不同温度下碱性橙与抗体和牛血清白蛋白两种相互作用,在300～600 nm的发射波长,比较了两种相互作用的差异.结果表明,碱性橙与抗体结合为单一的静态猝灭过程,二者之间的作用力主要为静电作用力；在溶液中,二者以摩尔比1∶1结合,结合常数为3.88×104 L/mol(25.C),3.73×104 L/mol(37.C)和2.35×104 L/mol (45.C)；碱性橙距抗体分子色氨酸残基最短距离(r)为5.52 nm.碱性橙与BSA的结合也为静态猝灭,作用力为静电作用力.但碱性橙与抗体作用过程中形成了激基复合物,与BSA则不形成激基复合物.

Fluorescence Spectra Study on Specific and Non-specific Interactions Between Chrysoidine and Proteins

Chrysoidine was used as a model analyte to study its interactions with two proteins,a specific anti-chrysoidine and bovine serum albumin(BSA) using fluorescence spectroscopy.The excitation wavelength was set at 280 nm and the emission wavelengths were scanned from 300 nm to 600 nm.The results showed that quenching mechanism of the antibody with chrysoidine was static quenching procedure and the interaction of chrysoidine with antibody was electrostatic interaction.The amount of binding sites was one with the binding constant 3.88×104 L/mol(25 ℃),3.73×104 L/mol(37 ℃),2.35×104 L/mol(45 ℃).The binding distance between antibody and chrysoidine was 5.52 nm.Similar to this,reaction of chrysoidine and BSA also indicated a static quenching mechanism and the interaction was an electrostatic interaction.The only difference between the two interactions was an exciplex formed between antibody and chrysoidine which was absent in its interaction with BSA.