Synthesis by Solid-phase
Since the discovery of PNA in the early 1990s, a lot of research has been done on its application as antisense and antigen probes. In order to further improve their properties, PNA has been conjugated to various molecules. Among them, small peptide fragments, usually derived from functional proteins, can deliver their specific properties of conjugates.
PNA-peptide conjugates can be assembled and synthesized through established solid-phase peptide synthesis schemes. Creative Peptides provides PNA-peptide conjugate synthesis services by solid-phase according to the rigorous synthesis process and will provide relevant synthesis cases for customer reference.
Synthesis Process
The main chain amine groups of PNA monomers currently on the market are protected by Fmoc or Boc, while the exocyclic amines of nucleobases (A, C and G) have Bhoc or Z protecting groups. Therefore, the PNA-peptide conjugate was synthesized by two chemical methods, Fmoc chemistry and Boc chemistry. The specific synthesis process is as follows:
Fig.1 Solid-phase synthesis process of peptide-PNA conjugates. (Koning M.; et al.2003)
1. Fix the PNA monomer to an acid labile joint on a suitable resin. Polyethylene glycol-polystyrene resin (PEG-PS, linker = rink amide) can be used in Fmoc chemistry, while PS (linker = methylbenzyl amine) resin is used in Boc chemistry.
2. Remove the N-terminal protecting group. Fmoc uses 20% DMF or Boc uses 50% TFA, and then extends with the next protected structural unit under the action of the coupling agent and caps the remaining amine with acetic anhydride.
3. Repeat this reaction cycle. Including the steps of deprotection, coupling and capping, and finally construct the immobilized and fully protected peptide-PNA conjugate.
4. Cleavage from the resin and deblocking of the protecting groups to obtain the target peptide-C-to-N-PNA conjugate.
PNA-C-to-N-peptide conjugates can also be constructed by a similar stepwise solid phase method.
Synthesis Example
Here are some examples of using Boc and Fmoc programs to prepare PNA-peptide chimeras for reference.
Example | Sequence | Type of peptide |
|---|---|---|
| The synthesis of a 125I-labeled PNA conjugated to the peptide octreotide by Boc-procedure | dF-c[CFdWKTC]-T | Octreotide (SMSTR binding) |
| The construction of a PNA–peptide library by Boc protocol | GRKKRRQRRRPPQ | Tat peptide |
| KFFKFFKFFK | Bacterial cell membrane active peptide | |
| The preparation of antiproliferative PNA constructs containing a nuclear localization sequence by Fmoc protocol | PKKKRKV | NLS |
| Several other PNA–peptide conjugates with specific functions by solid-phase approach | KKKK | Cationic |
| AAVALLPAVLLALLA | H region from Kaposi FGF | |
| EQKLISEEDLNA | C-myc tag sequence |
Our Advantages
- More than 10 years of industry-leading scientific expertise.
- Extensive ability to handle complex synthesis.
- Product quality assurance. Effective procedures and methods to ensure high quality, and provide product test report.
- Fast synthesis cycle.
Creative Peptides ’ scientists are committed to helping our customers shorten the test journey with years of valuable experience. For more details, please feel free to contact us.
Reference
- Koning M.; et al.Synthetic developments towards PNA–peptide conjugates. Current Opinion in Chemical Biology,2003, 7(6):734-740.
Notice: Products and services are used only for scientific research.
