Characterization of an anti-FLAG antibody binding protein in V. cholerae

Biochem Biophys Res Commun. 2020 Jul 30;528(3):493-498. doi: 10.1016/j.bbrc.2020.05.169. Epub 2020 Jun 3.


FLAG-tags are commonly used for protein abundance measurements and for identification of protein-protein interactions in living cells. We have observed that the cholera pathogen Vibrio cholerae encodes a FLAG-antibody-reactive protein and identified this protein as an outer membrane porin, Porin4, which contains a sequence very similar to the 3xFLAG epitope tag. We have demonstrated the binding affinity of the conserved peptide sequence (called Porin 4 tag) in Porin4 against monoclonal anti-FLAG M2 antibody. In addition, we created a porin4 deletion mutant, which can be used for background-less FLAG antibody detection experiments.

Keywords: 3xFLAG tag; Affinity tag; Epitope tag; Monoclonal anti-FLAG M2 antibody and Porin4; Non-specific binding.