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Updated: Mar 30, 2026
Targeted Antibody Blocking by a Dual-Functional Conjugate of Antigenic Peptide and Fc-III Mimetics DCAF
Published on: September 17, 2019
Fc-Small Molecule Antibody Mimetics
Erik D Wold1, Jun Y Axup1, Brunhilde H Felding1
1Department of Chemistry and the Skaggs Institute for Chemical Biology, ‡Department of Chemical Physiology, and §Department of Cell and Molecular Biology, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States.
Researchers developed a novel method to create antibody mimetics by attaching small molecules to Fc fragments. This approach yields targeted therapeutics, exemplified by an Fc-folic acid conjugate effective against folate receptor-positive cancers.
Area of Science:
- Biotechnology
- Drug Discovery
- Immunology
Background:
- Antibody therapeutics offer high specificity and good pharmacokinetics.
- Developing antibodies against specific functional epitopes can be challenging.
- Targeting disease-associated antigens requires high specificity and affinity.
Purpose of the Study:
- To develop a generalizable method for synthesizing antibody mimetics.
- To create antibody-like drugs by conjugating small molecules to Fc fragments.
- To demonstrate proof of concept using an Fc-folic acid conjugate targeting folate receptor-alpha (FR-α).
Main Methods:
- Site-specific conjugation of small molecules with high affinity to disease antigens onto an Fc fragment.
- Production of an E269pAcPhe Fc antibody fragment.
- Labeling the Fc fragment with a linker-modified folic acid compound.
- Assessing specificity using flow cytometry on FR-α positive breast cancer cells (MDA-MB-231).
Main Results:
- Successful generation of an Fc-folic acid antibody-mimetic.
- Demonstrated specificity of the Fc-folic acid conjugate for FR-α.
- Fc-folic acid conjugate binding was confirmed and competed by excess folic acid.
- The method is generalizable for creating Fc-small molecule conjugates.
Conclusions:
- Fc-small molecule conjugates represent a promising new class of antibody-like therapeutics.
- This approach overcomes challenges in developing antibodies for certain epitopes.
- The developed antibody mimetics offer potential for targeted cancer therapy.
