Peptide Synthesis & Purification
Peptides are molecules of crucial importance in the fields of healthcare, nutrition and cosmetics. Several technologies for production are available, among which chemical and enzymatic synthesis are especially relevant.
Space Peptides synthesizes your peptides by chemical methods, most typically using Solid Phase Peptide Synthesis (SPPS). Alternative chemical methods include solution phase (LPPS) and hybrid approaches.
The crude peptide subsequently is purified by preparative reverse phase High Performance Liquid Chromatography (HPLC)
Solid Phase Peptide Synthesis (SPPS)
SPPS enables rapid peptide chain assembly through successive reactions of amino acid derivatives on an insoluble, porous support. The solid support consists of small polymeric resin beads functionalized with reactive groups (e.g., amine or hydroxyl) that link to the growing peptide. Since the peptide remains covalently attached to the support, excess reagents and side products are easily removed by washing and filtration, avoiding time-consuming isolation steps required in solution-phase synthesis.
Each amino acid must be protected on its N-terminus and side chain using groups like Boc (acid-labile) or Fmoc (base-labile), depending on the strategy. SPPS involves repeated cycles of N-terminal deprotection and coupling reactions, with resin washing between steps.
First, an amino acid is coupled to the resin, then deprotected and reacted with the next amino acid. This cycle continues until the full sequence is synthesized. Optional capping steps block unreacted ends from further reaction.
Finally, the crude peptide is cleaved from the solid support while removing all protecting groups using strong acids like trifluoroacetic acid or a nucleophile. It can then be precipitated from a non-polar solvent like diethyl ether to remove organic-soluble byproducts.
Other Peptide Synthesis technologies
Fragment Liquid Phase Peptide Synthesis and limitations of SPPS
Synthetic accessibility of Peptides typically is limited by Peptide sizes in the range of 70 amino resulting from limited cumulative reaction yields of SPPS. Synthetic difficulty often also is sequence dependent; typically aggregation-prone sequences such as amyloids are difficult to make. Longer lengths can be accessed by using ligation approaches such as native chemical ligation, where two shorter fully deprotected synthetic peptides can be joined together in solution.
biotechnological Processes and their limitations
Only linear peptide containing natural amino-acids like insulin can be produced through recombinant processes, limiting the peptide chemical space that one has to considered for the project. On the contrary, peptide synthesis allows the consideration of the whole chemical space no matter the sequence and the topologies. Regarding that Luraglutide, a 31 amino acids residues drugs, costs the same if produced through recombinant process or peptide synthesis, we strongly advice for peptide synthesis.
Continuous Flow processes
Either SPPS or fragment-based LPPS technologies can be implemented in continuous flow, depending on the needs of the project. Continuous flow offers advantages such as improved reaction control, scalability, and reduced synthesis time. The choice between the two methods typically depends on factors like peptide length, complexity, and desired throughput.
peptides purification
Preparative Reverse Phase HPLC
The crude peptide typically is purified using reverse-phase HPLC. The purification process, especially of longer peptides can be challenging, because small amounts of byproducts, which typically are very similar to the product, need to be removed. For this reason so-called continuous chromatography processes such as MCSGP are increasingly being used in commercial settings to maximize the yield without sacrificing on purity levels.
the difference between peptide purity and peptide content
Peptide purity is a percentage of the target sequence as determined by HPLC. The impurities found in a peptide will include deletion sequences, truncated sequences, and incompletely deprotected sequences. Peptide content can be determined in a few different ways depending on the sequence and is a measurement of the native peptide present versus the non-peptide components.
Modifications
Looking for something a bit more specialized?
Space Peptides offers the following custom peptide modifications to meet your project’s specific needs:
- Lipidation
- Glycosylation
- Phosphorylation
- Sulfation and sulfonation
- Unnatural amino acids
- Hydrophobic sequences
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