Nonnatural Amino Acid-based VLP Modification Service

Nonnatural Amino Acid-based VLP Modification Service

CD BioSciences is a leading global provider of custom services for the surface functionalization of virus-like particles (VLPs) by genetic fusion and chemical conjugation methods in close collaboration with our customers and experts. Our experienced scientists focus on a sophisticated VLPlant^TM platform and are happy to meet the specific requirements of each client, providing the most appropriate solution to deliver high quality results to you in the shortest possible time.

Overview of Nonnatural Amino Acid-based VLPs Modifications

Many nonnatural amino acids other than 20 natural amino acids can be embedded in VLPs through global methionine replacement and amber stop codon suppression to form cVLPs. Azidohomoalanine (AHA) and p-amino-phenylalanine (pAF) are two nonnatural amino acids that are frequently embedded in the shell proteins of VLPs.

• Global Methionine Replacement
  Methionine-assisted bacterial or cell-free protein synthesis is first used to limit the supply of methionine. AHA is very similar to methionine, and when the supply of methionine is rate-limiting, AHA will be incorporated at each AUG codon. By optimizing the procedure, the protein yield of global methionine substitution can be increased, but this approach is not work for pAF.
• Amber Stop Codon Suppression
  Nonnatural synthetic enzymes and tRNAs that do not react with natural amino acids are used to dope nonnatural amino acids at the amber stop codon UAG. Although this method is more difficult to implement and has lower yields, it is work for pAF.

Despite the drawbacks of both global methionine replacement and amber stop codon suppression, these methods have been used to incorporate unnatural amino acids with unique active side chains into VLPs via click chemistry.

Stick or click approaches for decoration of virus-like particle (VLP) vaccines. (Brune KD, et al., 2018)

Click Chemistry

Click chemistry, also known as "linkage chemistry" and "rapid-pairing combinatorial chemistry", focuses on the rapid and reliable completion of chemical synthesis through the splicing of small units. Click chemistry is a very powerful technique for rapid and efficient covalent linking of molecules in biology, biochemistry and biotechnology, and has made a significant contribution to the field of chemical synthesis. Because of the ease of modification and incorporation of azide and alkyne groups in biological scaffolds, azide−alkyne cycloadditions (AAC) remain the leading technique in click reactions.

• Copper Catalyzed Azide Alkyne Cycloaddition (CuAAC)
• Ruthenium Catalyzed Azide Alkyne Cycloaddition (RuAAC)
• Metal-free Click Chemistry and Strain Promoted Azide Alkyne Cycloaddition (SPAAC)

Two competitive pathways for the Cu-catalyzed azide−alkyne cycloaddition (CuAAC). (Fantoni NZ, et al., 2021)

The most common click chemistry reaction employing the construction of chimeric VLPs (cVLPs) based on unnatural amino acids is the reaction of copper-catalyzed azide-alkyne cycloaddition.

Our Services

CD BioSciences provides global customers with VLP modification services based on unnatural amino acids, and we have the ability and confidence to meet your needs for fast and accurate experiments. If you are interested in our services, you can contact us for more details, we are glad to hear from you and look forward to working with you.

Process of Our Service

References

1. Fantoni NZ.; et al., A Hitchhiker's Guide to Click-Chemistry with Nucleic Acids. Chem Rev. 2021, 12:7122-7154.
2. Brune KD.; et al., New Routes and Opportunities for Modular Construction of Particulate Vaccines: Stick, Click, and Glue. Front Immunol. 2018, 9:1-15.