Computer-aided precise hapten design strategy for the monospecific detection of altrenogest: Experimental validation and analysis of the molecular recognition mechanism

Altrenogest is one of the most commonly used steroid hormones; however, there are currently no relevant reports on monospecific molecular recognition elements and immunoassay methods for altrenogest. Herein, a computer-aided precise hapten design strategy was proposed for monospecific monoclonal antibodies (mAb) preparation. Based on this strategy, a monospecific and sensitive mAb-D7 was prepared for the first time. The mAb-D7 has the 50 % inhibitory concentration (IC 50 ) of 0.12 ng/mL for altrenogest and does not cross-react with other common steroid hormones. Additionally, a single-chain variable fragment (scFv) for altrenogest was constructed for the first time, which exhibits an IC 50 of 1.7 ng/mL for altrenogest. The molecular recognition mechanism studies showed the monospecific mAb-D7 to altrenogest originated from the amino acids PHE-94 and LEU-237, demonstrating the reliability of this strategy. Finally, two monospecific, rapid, and sensitive immunoassays were established for altrenogest in pork and pork liver for the first time.