DNA-Conjugated Peptide Synthesis

DNA-peptide conjugates are molecular chimeras with a nucleic acid portion and a polypeptide that are widely used in therapeutics and nanotechnology. CD Formulation provides custom synthesis and ligation of peptide and DNA oligomers to clients worldwide. DNA oligomers are conjugated to peptides via functionalized phosphoramidite monomers, the most common reactive moieties being amines, thiols, alkoxyamines or hydrazines, aldehydes, azides/alkynes.

What Are DNA-Conjugated Peptides?

DNA-conjugated peptides, also known as DNA-peptide conjugates are chimeric molecules composed of nucleic acid parts covalently linked to peptides. Potential applications of DNA-peptide constructs range from therapy to nanotechnology. A common DNA-peptide conjugation strategy is to combine cell-penetrating peptides with phosphosulfate DNA chains to enhance nuclease attack. When combined with peptides, DNA is more resistant to nucleases, and when linked to cationic peptides, double-strand formation can be enhanced. In addition, DNA-peptide conjugates have been used in a variety of sensing systems.

Fig. 1 Synthesis pathway to achieve DNA–peptide conjugates by solution phase modification. (Taylor ER, et al., 2022)

Explore Our Custom DNA-Conjugated Peptide Synthesis Services

CD Formulation offers several custom synthesis options for peptides and DNA listed below, but we are happy to discuss conjugation projects using your own DNA or peptides.

• BNA/DNA-peptide synthesis and conjugation.
• Peptide nucleic acid conjugates.
• DNA-peptide-DNA conjugates.
• DNA-peptide-BNA hybrids.
• DNA-peptide-BNA.
• Double-stranded DNA-peptide conjugates.
• Peptide-DNA-peptide conjugates.
• Conjugation of single amino acids to DNA.
• Conjugation of peptides to BNA, LNA, BNA, ZNA, morpholine or other nucleic acid analogs.
• Labeling of peptide-DNA conjugates with fluorescent dyes or other modifications.

The conjugation of these macromolecules to peptides is often hampered by side reactions. To overcome this difficulty, we use different synthetic methods for the chemical synthesis of DNA-peptide conjugates. The two most common approaches are:

Full Stepwise Synthesis

Stepwise synthesis is an online solid-phase synthesis protocol in which peptides and oligonucleotides are synthesized sequentially, usually on the same solid support.

Post-Synthesis Conjugation

Post-synthesis conjugation is a chemoselective ligation reaction that introduces reactive groups to oligonucleotides and peptides. This strategy includes the formation of a variety of bonds, such as amide, disulfide, oxime, carbonyl, or cycloaddition click reactions.

At CD Formulation, both peptides and DNA are synthesized independently using standard Boc or Fmoc chemistry. Then the peptide or oligonucleotide is immobilized on a solid support and conjugated after synthesis. The intact oligonucleotide-peptide conjugate is cleaved from the support.

Our DNA-Peptide Conjugation Strategies

Fig. 2 Schematic diagram of DNA and peptide conjugation. (CD Formulation)

Coupling to Cysteine-containing Peptides via Thioether Bonds

The N-terminus or C-terminus of the peptide often emerges as a favored locus for the attachment to the 3' or 5' extremities of DNA strands. This sophisticated methodology hinges upon the nuanced interaction of N- or C-terminally cysteine-conjugated peptides engaging in a reactive liaison with maleimide-activated DNA. The most common options for conjugation are:

• Disulfide bond conjugation using thiol groups on the peptide and DNA molecules. The disulfide bond is unstable, and suitable for reduction to separate DNA and peptide.
• Amide bond conjugation via thiol and amino groups on DNA and peptide.

If the peptide has an internal Cys, we will use other strategies such as oxime formation by reacting hydroxylamine-modified peptides with aldehyde-modified oligonucleotides.

Click Chemistry Coupling

Our experts use copper-free click chemistry to conjugate alkyne-modified DNA oligonucleotides to azide-modified peptides to form DNa-conjugated peptides.

DNA-Conjugated Peptide Modification

Modifications can be incorporated into the DNA or peptide molecules, or both molecules (if appropriate). Modifications include:

• Phosphorothioate bonds on the backbone of the DNA molecule.
• Modified bases on the DNA.
• Modified amino acids incorporated into the peptide sequence.
• Fluorescent and dye labels, including but not limited to FAM, TAMRA, BHQ1, and BHQ2.
• Biotinylation
• Spacers

Delivery Specifications of DNA-Conjugated Peptide

Peptide Manufacturing & Analytical Services

In addition to peptide synthesis capabilities, CD Formulation combines flexible GMP manufacturing facilities with cutting-edge peptide analytical knowledge to provide a full range of quality control testing services to accelerate the commercialization of your products, including:

Publication

CD Formulation is a trusted partner for peptide synthesis. Please don't hesitate to contact us if you are considering using DNA-conjugated peptides in your project. We look forward to cooperating with you.

How It Works

STEP 1

Submit a service request describing your specific research or development need.

STEP 2

We'll email you to provide your quote and confirm order details if applicable.

STEP 3

Execute the project with real-time communication, and deliver the final report promptly.