Investigation of an Immunoassay with Broad Specificity to Quinolone Drugs by Genetic Algorithm with Linear Assignment of Hypermolecular Alignment of Data Sets and Advanced Quantitative Structure–Activity Relationship Analysis

A polyclonal antibody against the
quinolone drug pazufloxacin (PAZ)
but with surprisingly broad specificity was raised to simultaneously
detect 24 quinolones (QNs). The developed competitive indirect enzyme-linked
immunosorbent assay (ciELISA) exhibited limits of detection (LODs)
for the 24 QNs ranging from 0.45 to 15.16 ng/mL, below the maximum
residue levels (MRLs). To better understand the obtained broad specificity,
a genetic algorithm with linear assignment of hypermolecular alignment
of data sets (GALAHAD) was used to generate the desired pharmacophore
model and superimpose the QNs, and then advanced comparative molecular
field analysis (CoMFA) and advanced comparative molecular similarity
indices analysis (CoMSIA) models were employed to study the three-dimensional
quantitative structure–activity relationship (3D QSAR) between
QNs and the antibody. It was found that the QNs could interact with
the antibody with different binding poses, and cross-reactivity was
mainly positively correlated with the bulky substructure containing
electronegative atom at the 7-position, while it was negatively associated
with the large bulky substructure at the 1-position of QNs.

本研究制备了一株针对喹诺酮类药物帕珠沙星（pazufloxacin, PAZ）的多克隆抗体（polyclonal antibody），该抗体意外展现出宽泛的特异性，可同时检测24种喹诺酮类药物（quinolones, QNs）。所建立的竞争间接酶联免疫吸附试验（competitive indirect enzyme-linked immunosorbent assay, ciELISA）对这24种QNs的检出限（limits of detection, LODs）介于0.45至15.16 ng/mL之间，且均低于其对应的最大残留限量（maximum residue levels, MRLs）。为深入阐释该抗体宽泛特异性的成因，本研究采用数据集超分子比对线性分配遗传算法（genetic algorithm with linear assignment of hypermolecular alignment of data sets, GALAHAD）构建目标药效团模型并对QNs进行分子叠合；随后借助改进型比较分子场分析（comparative molecular field analysis, CoMFA）与改进型比较分子相似性指数分析（comparative molecular similarity indices analysis, CoMSIA）模型，探究QNs与抗体之间的三维定量构效关系（three-dimensional quantitative structure–activity relationship, 3D QSAR）。研究结果表明，QNs可通过不同结合模式与抗体产生相互作用，交叉反应性主要与喹诺酮母核7位含电负性原子的庞大取代基呈正相关，而与1位的大体积取代基呈负相关。