Molecular chaperone effects on recombinant yield and binding characteristics of an ABA-specific scFv in

Introduction: Recombinant single-chain variable fragments (scFvs) are promising antibody formats for cost-effective and scalable production. However, their soluble expression in Escherichia coli is often limited by misfolding and aggregation, particularly for scFvs targeting small molecule haptens such as abscisic acid (ABA). To address this bottleneck, molecular chaperones can be co-expressed to enhance folding efficiency and functional yield. Methods: An ABA-specific scFv was expressed in E. coli BL21(DE3) using five different chaperone plasmids (pG-KJE8, pGro7, pKJE7, pG-Tf2, and pTf16). Soluble expression was quantified by His-tag ELISA, and protein identity was confirmed by SDS-PAGE and Western blot. Functional characterization included competitive ELISA for IC Results: Trigger Factor (pTf16) significantly improved soluble scFv yield (19.65%) compared to the control (14.20%). The pKJE7 system achieved the highest sensitivity with the lowest IC Discussion: This study highlights that molecular chaperone choice influences both structural fidelity and functional performance of ABA-scFv in E. coli. While pKJE7 favors high sensitivity, pTf16 yields highly specific and structurally stable antibodies. These findings establish a practical basis for developing low-cost ABA immunoassays with tailored performance for agricultural biotechnology.