This invention introduces a fast, site-specific enzymatic method for attaching oligonucleotides to proteins with near-traceless precision, enabling cleaner, more functional conjugates for diagnostics, therapeutics, and nanotechnology.
Background: Conventional methods for protein–oligonucleotide conjugation often suffer from slow reaction rates, harsh chemical conditions, and non-specific linkages that interfere with protein function or trigger immune responses. Many approaches also require bulky chemical tags or multi-step protocols, reducing biocompatibility and limiting use in sensitive biomedical applications. A clean, precise, and efficient conjugation strategy is needed to advance the reliability of protein–nucleic acid hybrids in therapeutic and diagnostic contexts.
Technology Overview: This invention uses a two-component, biocatalytic method involving hedgehog steroyl transferase (HST-I). The protein of interest (POI) is genetically fused to HST-I via an electrophilic glycine linker. A sterol-modified oligonucleotide is then introduced, and HST-I catalyzes the covalent bond formation at the glycine site while self-cleaving from the POI. This process yields a clean 1:1 protein–oligonucleotide conjugate with only a single glycine residue left behind. The reaction occurs rapidly (10–20 minutes) under mild, aqueous, room-temperature conditions, eliminating the need for bulky tags or harsh chemical conjugation methods.
Advantages: • Leaves only one glycine residue at the conjugation site (“near-traceless”) • High specificity: 1:1 conjugation at the C-terminus of the protein • Compatible with diverse proteins and sterol-modified oligonucleotides • Rapid (10–20 minutes) reaction under mild aqueous conditions • Simplifies protocols by eliminating complex, multi-step chemical methods • Avoids bulky modifications that interfere with protein function or stability
Applications: • Site-specific antibody–oligonucleotide conjugates for targeted drug delivery • High-sensitivity biosensors and diagnostic chips • Protein immobilization for lab-on-chip and microarray platforms • Nanoparticle functionalization for precision assembly and imaging • Synthetic biology and proteomics applications requiring traceless protein labeling
Intellectual Property Summary: • US Provisional Application 62/409,655 – Filed October 18, 2016 • US Patent 10,738,338 – Application 15/782,391, Issued August 11, 2020 • US Patent 12,077,795 – Application 16/989,843, Issued September 3, 2024
Stage of Development: Patented and lab validated – Demonstrated site-specific, traceless protein–oligonucleotide conjugation across multiple protein and nucleic acid substrates. TRL ~4–5.
Licensing Status: This technology is available for licensing.
Licensing Potential: Strong potential for licensing to biotechnology, pharmaceutical, and diagnostics companies seeking precise, scalable conjugation technologies for targeted therapies, biosensors, and nanotechnology platforms.
Additional Information: Validation data, reaction kinetics, and compatibility results across multiple proteins and oligonucleotides available upon request.
Inventors: Brian Callahan, Timothy Owen