Figure 7.

Affinity chromatography binding assay. SsZntA is treated with TEVp to remove the HisTag, in this way it cannot bind to a Ni²⁺ beads, while the HisTagged nanobody can. The binding was assessed by incubating HisTag-free SsZntA with HisTagged Nb and loading them to an Ni-NTA column. When SsZntA forms a complex with the Nb, it indirectly binds to the Ni²⁺ beads (via the Nb’s HisTag) and can be eluted from the Ni²⁺-immobilized resin. N.B. All the representations are out of scale for clarity.