PeptideSyn^TM Peptide Synthesis Technology

The conventional solid phase peptide synthesis (SPPS) typically uses long coupling time of up to one hour or more, extended deprotection times, multiple wash steps as well as Kaiser tests to insure complete acylations. This increases synthesis time especially when synthesizing the complex peptides such as beta-amyloid, which has high hydrophobicity of the C-terminal segment and subsequent on-resin aggregation. The rate of amino acid acylation is heavily dependent on the properties of the coupling. Therefore, the ability to assemble peptides faster with a reasonable quality is highly desirable.

LifeTein's PeptideSyn^TM technology is a very practical platform for the synthesis of peptides for pharmaceutical companies, active pharmaceutical ingredient (API) purpose and research laboratories. The PeptideSyn^TM technology has been used for in-house testing of multiple selected biologically active peptides with a broad range of properties including long and short peptides, as well as peptides containing D-amino acids or pseudoproline dipeptides using various coupling reagents such as HBTU, HATU, HCTU, ByBroP, BOP, PyBOP and TBTU. The PeptideSyn^TM technology allows us to have the flexibility to choose affordable, highly efficient coupling reagents for fast SPPS.

One study using the PeptideSyn_TM technology shows that the synthesis of the human beta-amyloid (1-42) peptide (H-DAEFRHDSGYEVHHQKLVFFAEDVGSNKGAIIGLMVGGVVIA-OH) using HCTU as activators renders a total synthesis time of 15 h with similar purity to the long synthesis. Wang-ChemMatrix, HMPB-ChemMatrix, and Wang-PSLL were compared for their efficiency on different synthesis. The C-terminal pentapeptide was incorporated by stepwise synthesis. The coupling yields for the peptide segment were up to 90% to 95%. After treatment with hydrogen fluoride and purification, synthetic human beta-amyloid (1-42) peptide was obtained in an overall yield of more than 75-88%.

Using appropriate coupling and deprotectant reagents linked to the correct resin, LifeTein's PeptideSyn^TM technology provides our customers with reduced total peptide synthesis time and higher quality.

Incomplete deprotection steps and amino acid-coupling reactions can cause big problems for the downstream process. Longer reaction time and/or increased reagent strength could solve the sluggish deprotection reaction problems. However, in some extreme cases, these methods are not sufficient and the protecting group cannot be removed efficiently. Some sequences are prone to undergo self-association by hydrogen bonding because of the side chains. This leads to aggregation and to the formation of beta-sheet-like secondary structures that can make peptide synthesis impossible to continue.

LifeTein's optimized protocol and PeptideSyn technology provide a method for circumventing the difficult sequences problem. The technology can change the peptide structure by protecting some of peptide amide bonds, giving rise to peptides containing tertiary amides at periodic intervals. This leads to better salvation of the peptide chain and to more efficient deprotection and coupling reactions. Using Fmoc/tBu approach on our proprietary resin, the routine synthesis process of difficult sequences is improved.

Case Study: Client requested a very hydrophobic 68 amino acid peptide (85% purity) with FITC modification at the N terminus. The peptide was successfully synthesized in 4 weeks.

HPLC Results

Mass Spectrometry Results