Isolation of full-length IgG antibodies from combinatorial libraries expressed in the cytoplasm of Escherichia coli.

ABSTRACT: Here we describe a facile and robust genetic selection for isolating full-length IgG antibodies from combinatorial libraries expressed in the cytoplasm of redox-engineered Escherichia coli cells. The method is based on the transport of a bifunctional substrate comprised of an antigen fused to chloramphenicol acetyltransferase, which allows positive selection of bacterial cells co-expressing cytoplasmic IgGs called cyclonals that specifically capture the chimeric antigen and sequester the antibiotic resistance marker in the cytoplasm. The utility of this approach is first demonstrated by isolating affinity-matured cyclonal variants that specifically bind their cognate antigen, the leucine zipper domain of a yeast transcriptional activator, with subnanomolar affinities, which represent a ~20

SUBMITTER: Robinson MP 

PROVIDER: S-EPMC10267130 | biostudies-literature | 2023 Jun

REPOSITORIES: biostudies-literature