GAP Peptide Synthesis (GAP-PS) is remarkably cost effective, combining the advantages of both solution phase and F-moc chemistry. Coupling reactions are run in solution, near the saturation point of the solvent of choice. The approach creates significant economic advantages due to reduction in both solvent and other raw material waste. The reduction in material consumption translates to significant savings in addition to the process being environmentally sensitive – enabling reuse and recycling in some cases.
Using recently published data from a prominent peptide CMO, we completed a detailed, comparative assessment between GAP-PS and SPPS. Choosing an example 5-mer peptide as the basis for comparison, we analyzed costs per coupling step across methods. Key savings estimates identified include >80% reduction in anchor cost achieved by replacing the SPPS resin with the GAP protecting group. Also projected is a >40% reduction in solvent costs. In total, it is estimated that GAP-PS can reduce raw material and solvent costs by up to 48%. This estimates are of course intended to provide a benchmark, and can vary depending on the specific target.
Because GAP-PS coupling reactions are highly efficient, deletion / insertion impurities are rare. This translates to higher crude peptide purity, which can further reduce production costs during chromatographic purification. In some cases, such as for cosmetic products, the crude purity is sufficient, and chromatography is not needed.