Chemical shift assignments of a camelid nanobody against aflatoxin B1.

Nanobodies (Nbs) are the variable domain of the heavy-chain antibodies produced from Camelidae, which possess comparable binding affinities and specificity to conventional antibodies. Nbs have become valuable and versatile tools for numerous biotechnology applications due to their small size (12-15 kDa), high solubility, exceptional stability, and facile genetic manipulation. The interactions between Nbs and protein antigens have been well-studied, but less work has been done to characterize their ability to bind small molecule haptens. Here we present the backbone and side-chain assignments of the 1H, 13C and 15N resonances of Nb26 (123 amino acids), a nanobody that recognizes the hapten aflatoxin B1 (AFB1). These assignments are preliminary work towards the determination of the structure of free Nb26 using NMR spectroscopy, which will provide useful information about the complex structure of "Nb26-AFB1" and the recognition mechanism about how Nb26 binds to AFB1.