Fatty acid-binding proteins (FABPs) belong to a family of proteins that transports fatty acids in the cytosol and regulates cellular functions like membrane phospholipid synthesis, lipid metabolism, and mitochondrial β oxidation. In this study, we synthesized ten novel derivatives from BMS309403, a biphenyl azole compound specific for FABP4, and analyzed their affinity and specificity for FABP3, FABP4, and FABP5, which possess 60% of homology in amino acid sequence. Here, we used 1-anilinonaphthalene 8-sulfonic acid (ANS) displacement assay and found that Ligand 1 has highest affinity for FABP3, with comparable affinity for FABP4 and FABP5. The apparent dissociation constant of BMS309403 was identical to that of arachidonic acid and docosahexaenoic acid. Docking studies with X-ray structural data showed that these novel derivatives obtained by the substitution of phenoxyacetic acid in BMS309403 but not BMS309403 have high or moderate affinity for FABP3. We further found that substitution of a phenyl group and alkyl group caused steric hindrance between 16F, the portal loop and 115L, 117L, respectively, leading to decrease in their affinity for FABPs. In conclusion, our study provides a novel strategy for development of specific ligand for each FABP.

脂肪酸结合蛋白（FABP）属于蛋白质家族，可在细胞质中转运脂肪酸并调节细胞功能，如膜磷脂合成，脂质代谢和线粒体β氧化。在这项研究中，我们从BMS309403（一种对FABP4特异的联苯唑化合物）合成了十种新颖的衍生物，并分析了它们对FABP3，FABP4和FABP5（在氨基酸序列中具有60％的同源性）的亲和力和特异性。在这里，我们使用1-苯胺基萘8-磺酸（ANS）置换分析，发现配体1对FABP3的亲和力最高，与FABP4和FABP5的亲和力相当。BMS309403的表观解离常数与花生四烯酸和二十二碳六烯酸的表观解离常数相同。用X射线结构数据进行的对接研究表明，通过在BMS309403中而不是BMS309403中苯氧乙酸取代获得的这些新型衍生物对FABP3具有高或中等亲和力。我们进一步发现，苯基和烷基的取代分别在16F，门环和115L，117L之间引起空间位阻，导致它们对FABP的亲和力降低。总之，我们的研究为每种FABP的特异性配体的开发提供了一种新颖的策略。