Isolation of Nanobodies Targeting the Secreted Dps Protein of Brucella

In this study, we identified and characterized two nanobodies, Nb29 and Nb45, that specifically target the secreted DNA-binding protein Dps of Brucella using a yeast surface display library.Following four rounds of screening with magnetic bead-based selection, Nb29 and Nb45 were isolated and validated by flow cytometry and ELISA.Nb29 exhibited a binding affinity of 0.468 M, while Nb45 showed moderate affinity with 1.384 M.Upon fusion via a glycine-serine linker, the resulting nanobody dimer demonstrated enhanced avidity (0.1912 M).These nanobodies, displaying specificity for Dps, owing to their small molecular size and improved avidity in dimeric form, hold promise as molecular tools for diagnostic development and potential therapeutic strategies against Brucellosis.Our findings provide a foundation for further engineering and application of nanobody-based technologies in targeting Brucella virulence factors.