基于Scatchard法的碳酸酐酶-脂质体与药物结合常数测定

 为更好地模拟药物小分子与碳酸酐酶在体内的相互作用,采用碳酸酐酶-脂质体毛细管电泳法,以4-羧基苯磺酰胺为分析对象建立碳酸酐酶药物筛选模型,并以此模型为基础计算12 种药物小分子与碳酸酐酶的结合常数,分析药物小分子与碳酸酐酶的相互作用。结果表明,4-羧基苯磺酰胺与碳酸酐酶-脂质体的结合常数为1.172×10⁴ mL·g^-1,具有较强的相互作用。基于此,筛选出4 种(咖啡酸、L-抗坏血酸、2, 4-二氯-5-磺酰胺基苯甲酸和4-氯-3-磺酰胺基苯甲酸)和5种(阿魏酸、马兜铃酸、没食子酸、原儿茶酸、烟酸)与复合物具有较强或较弱相互作用的药物。通过该法可快速、有效、经济地测定碳酸酐酶或其他靶标与药物的相互作用,缩短药物研发周期。

Binding interaction of carbonic anhydrase-liposome complex and medicinal molecules by Scatchard method

In this in vitro study, carbonic anhydrase-liposome complex was prepared to simulate the in vivo interactions between drug molecules and carbonic anhydrase. The complex was prepared by ultrasonic cell disruption, mixing and extrusion. Zeta potential and the size of carbonic anhydrase-liposome complex were -45.06 mV and 99.43 nm, respectively, indicating this complex is stable and suitable to apply for capillary electrophoresis. The complex was further added in running buffers as pseudo stationary phase in capillary electrophoresis, and 4-carboxybenzenesulfonamide (containing 2.2×10^-3 mol/L 4-methyl-2-pentanone as EOF marker) was added as a sample to establish the model of the interaction between the drug and carbonic anhydrase-liposome complex using Scatchard method. The binding constant in this model was 1.172×10⁴mL·g^-1. Among the 12 drugs studied using this method, caffeic acid, L-ascorbic acid, 2,4-dichloro-5-sulfamoylbenzoic acid, and 4-chloro-3-sulfamoyl benzoic acid had strong interactions with carbonic anhydrase-liposome complex, having higher binding constants than that of 4-carboxybenzenesulfonamide. Ferulic acid, aristolochic acid, gallic acid, protocatechuic acid, and nicotinic acid had weak interactions with carbonic anhydrase-liposome complex, having lower binding constants than that of 4-carboxybenzenesulfonamide. This method can be used to check interactions between carbonic anhydrase or other targets and drug molecules rapidly and effectively, reducing the development cycle of drugs.