Reshaping nanobodies for affinity purification on protein a.

Nanobodies (Nbs) are 15 kDa recombinant, single-domain, antigen-specific fragments derived from heavy-chain only antibodies (HCAbs) occurring naturally in species of Camelidae. The beneficial properties of Nbs make them suitable tracers for diagnostic and therapeutic purposes. Whereas Nbs with a terminal hexa-histidine tag (His-tag) are easily purified via immobilized metal affinity chromatography, previous studies revealed a negative impact of the His-tag on the biodistribution of Nb-based tracers.