Turning antibodies off and on again using a covalently tethered blocking peptide

Michael Brasino, Eli Wagnell, Sean Hamilton, Srivathsan Ranganathan, Michelle M. Gomes, Bruce Branchaud, Bradley Messmer, Stuart D. Ibsen

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


In their natural form, antibodies are always in an “on-state” and are capable of binding to their targets. This leads to undesirable interactions in a wide range of therapeutic, analytical, and synthetic applications. Modulating binding kinetics of antibodies to turn them from an “off-state” to an “on-state” with temporal and spatial control can address this. Here we demonstrate a method to modulate binding activity of antibodies in a predictable and reproducible way. We designed a blocking construct that uses both covalent and non-covalent interactions with the antibody. The construct consisted of a Protein L protein attached to a flexible linker ending in a blocking-peptide designed to interact with the antibody binding site. A mutant Protein L was developed to enable photo-triggered covalent crosslinking to the antibody at a specific location. The covalent bond anchored the linker and blocking peptide to the antibody light chain keeping the blocking peptide close to the antibody binding site. This effectively put the antibody into an “off-state”. We demonstrate that protease-cleavable and photocleavable moieties in the tether enable controlled antibody activation to the “on-state” for anti-FLAG and cetuximab antibodies. Protein L can bind a range of antibodies used therapeutically and in research for wide applicability.

Original languageEnglish (US)
Article number1357
JournalCommunications Biology
Issue number1
StatePublished - Dec 2022

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • General Biochemistry, Genetics and Molecular Biology
  • General Agricultural and Biological Sciences


Dive into the research topics of 'Turning antibodies off and on again using a covalently tethered blocking peptide'. Together they form a unique fingerprint.

Cite this