Generation and characterization of nanobodies targeting human pepsinogens.

Human pepsinogens (mainly pepsinogen I and pepsinogen II) are the major inactive precursor forms of the digestive enzyme pepsin which play a crucial role in protein digestion. The levels and ratios of human pepsinogens have demonstrated potential as diagnostic biomarkers for gastrointestinal diseases, particularly gastric cancer. Nanobodies are promising tools for the treatment and diagnosis of diseases, owing to their unique recognition properties. In this study, recombinant human pepsinogens proteins were expressed and purified as immunized antigens. We constructed a VHH phage library and identified several nanobodies via phage display bio-panning. We determined the binding potency and cross-reactivity of these nanobodies. Our study provides technical support for developing immunodiagnostic reagents targeting human pepsinogens. • Improved recombinant expression and purification of human pepsinogens. • An immune library with high diversity of VHH genes derived from a llama. • Selection, biopanning and screening of nanobodies targeting human pepsinogens. • Nanobodies with great specificity can be used to develop biosensors. [ABSTRACT FROM AUTHOR]