Abstract

We present a comprehensive study of the receptor–ligand interaction by spectral methods on the example of Concanavalin A lectin and 5 kDa chitosan modified with D-mannose. An improved method for the modification of chitosan with D-mannose and purification of these conjugates is developed. A novel approach to calculate the constants of the Concavalin A binding with the mannose-containing ligand is proposed. The calculation is based on the intensity reduction of the Amide II absorption band in the IR spectra normalized by Amide I during the receptor binding with the modified chitosan-mannose polymer. The linearization of the binding curves in Scatchard coordinates allows finding the complex dissociation constants whose value constituted (5.5 ± 0.3) × 10^–5 M. These results are confirmed by fluorescence polarization analysis. IR spectroscopy is found to be the most suitable and precise method for the calculation of dissociation constants, which does not require preliminary protein modification.

中文翻译：

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研究用甘露糖修饰的壳聚糖与Concavalin A相互作用的光谱方法，用于创建抗结核药物的地址传递系统

摘要

我们以伴刀豆球蛋白A凝集素和D-甘露糖修饰的5 kDa壳聚糖为例，通过光谱方法对受体-配体相互作用进行了全面研究。开发了一种用D-甘露糖修饰壳聚糖并纯化这些缀合物的改进方法。提出了一种新的方法来计算Concavalin A与含甘露糖的配体结合的常数。该计算基于在酰胺与改性的壳聚糖-甘露糖聚合物结合期间，酰胺II归一化的红外光谱中酰胺II吸收谱带的强度降低。Scatchard坐标中绑定曲线的线性化允许找到其值构成（5.5±0.3）×10 ^–5的复杂解离常数M.这些结果通过荧光偏振分析得到证实。发现红外光谱法是计算解离常数的最合适和最精确的方法，不需要初步的蛋白质修饰。