Abstract：
The immunogenicity of haptens determines the performance of the resultant antibody for small molecules. Rigidity is one of the basic physicochemical properties of haptens. However, few studies have investigated the effect of hapten rigidity on the strength of an immune response and overall antibody performance. Herein, we introduce three molecular descriptors that quantify hapten rigidity. By using of these descriptors, four rifamycin haptens with varied rigidity were designed. The structural and physicochemical feasibility of the designed haptens was then assessed by computational chemistry. Immunization demonstrated that the strength of induced immune responses, i.e., the titer and affinity of antiserum, was significantly increased with increased rigidity of haptens. Furthermore, molecular dynamic simulations demonstrated conformation constraint of rigid haptens contributed to the initial binding and activation of naïve B cells. Finally, a highly sensitive indirect competitive enzyme-linked immunosorbent assay was developed for detection of rifaximin, with an IC50 of 1.1 μg/L in buffer and a limit of detection of 0.2-11.3 μg/L in raw milk, river water, and soil samples. This work provides new insights into the effect of hapten rigidity on immunogenicity and offers new hapten design strategies for antibody discovery and vaccine development of small molecules.
摘要：
半抗原的免疫原性决定了所得抗体对小分子的性能。刚性是半抗原的基本理化性质之一。然而,很少有研究研究半抗原刚性对免疫应答强度和整体抗体性能的影响。在这里，我们引入了三个分子描述符来量化半抗原的刚性。通过使用这些描述符，设计了四种不同刚性的利福霉素半抗原。然后通过计算化学评估设计的半抗原的结构和物理化学可行性。免疫表明，诱导免疫反应的强度，即，抗血清的效价和亲和力，随着半抗原刚度的增加而显着增加。此外，分子动力学模拟表明，刚性半抗原的构象约束有助于初始B细胞的初始结合和激活。最后,开发了一种高度灵敏的间接竞争酶联免疫吸附测定法来检测利福昔明，在缓冲液中的IC50为1.1μg/L，在原料奶中的检出限为0.2-11.3μg/L，河水,和土壤样本。这项工作为半抗原刚性对免疫原性的影响提供了新的见解，并为小分子的抗体发现和疫苗开发提供了新的半抗原设计策略。
