Characterization of a Novel Monoclonal Antibody with High Affinity and Specificity against Aflatoxins: A Discovery from Rosetta Antibody-Ligand Computational Simulation

作者：Changrui Xing, Guanglei Li, Xin Zheng, Peng Li, Jian Yuan, Wenjing Yan · 发表于：Journal of Chemical Information and Modeling · 年份：2024 · DOI：10.1021/acs.jcim.4c00736 · 被引用次数：7 · 研究领域：Photosynthetic Processes and Mechanisms、Monoclonal and Polyclonal Antibodies Research、Synthesis and Biological Evaluation

Aflatoxin B1 (AFB 1 ) accumulates in crops, where it poses a threat to human health. To detect AFB 1, anti-AFB 1 monoclonal antibodies have been developed and are widely used. While the sensitivity and specificity of these antibodies have been extensively studied, information regarding the atomic-level docking of AFB 1 (and its derivatives) with these antibodies is limited. Such information is crucial for understanding the key interactions that are required for high affinity and specificity in aflatoxin binding. First, a 3D comparative model of anti-AFB 1 antibody (Ab-4B5G6) was predicted from the sequence using RosettaAntibody. We then utilized RosettaLigand to dock AFB 1 onto ten homology models, producing a total of 10,000 binding modes. Interestingly, the best-scoring mode predicted strong interactions involving four sites within the heavy chain: ALA33, ASN52, HIS95, and TRP99. Importantly, these strong binding interactions exclusively involve the variable domain of the heavy chain. The best-scoring mode with AFB 1 was also obtained through AF multimer combined with RosettaLigand, and two interactions at TRP and HIS were consistent with those found by Rosetta antibody-ligand computational simulation. The role of tryptophan in π interactions in antibodies was confirmed through mutation experiments, and the resulting mutant (W99A) exhibited a >1000-fold reduction in binding affinity for AFB 1 and analogs, indicating the effect of tryptophan on the stability of CDR-H3 region...