Biopanning, Heterologous Expression, and Characterization of a Shark-Derived Single-Domain Antibody Fusion Protein against Pancreatic Lipase

Nowadays, obesity severely impacts human health and isthe fifthleading risk factor that leads to death globally. Pancreatic lipase(PL) inhibitors have attracted extensive attention owing to theirrole in effective prevention and treatment of obesity. Here, a shark-derivedsingle-domain antibody fusion protein was used to inhibit PL for thefirst time. After biopanning, the heterologous expression system pET28a-SUMO-D2was constructed using the method of double restriction enzyme digestionand T4 ligase to achieve the soluble expression of the PL-specificantibody gene D2. According to the calculation of protein concentration,the final expression of fusion protein PL-D2S was 1.183 mg per literof Luria Bertani broth. The binding ability of the soluble fusionprotein PL-D2S to PL was identified. Enzyme-linked immunosorbent assayresults showed that the fusion protein PL-D2S exhibited a strong bindingaffinity to PL. The experimental results of PL inhibition of PL-D2S in vitro showed that the fusion protein could significantlyinhibit the activity of PL, with an IC50 of 404 mu g/mL.Our study shows that the fusion protein PL-D2S is a potential PL inhibitorto prevent and treat obesity.