FIG. 4.

In vivo biotinylation of BacMPs. (A) Schematic diagram of the preparation and in vivo biotinylation of BacMPs. Plasmid pUMtBL13B containing the truncated biotin ligase and mms13-bap gene was introduced into wild-type AMB-1 (step a). BacMPs were biotinylated by coexpressed truncated E. coli biotin ligase and Mms13-BAP (step b). The AMB-1 transformant harboring pUMtBL13B was disrupted to release biotinylated BAP-BacMPs (step c). Biotinylated BAP-BacMPs were magnetically separated and purified by stringent washing (step d). (B and C) The in vivo biotinylation of BAP-BacMPs was evaluated using ALP-labeled antibiotin antibody and luminescent substrate in a method based on enzyme-linked immunosorbent assay (B) and Western blotting (C). WT, wild type.