Membrane-based tide synthesis
Tide synthesis techniques — solid-phase peptide synthesis (SPPS) and liquid-phase peptide synthesis (LPPS) — have issues with purity, yield and batch variability. Scientists of the 'Membrane enhanced tide synthesis - A new paradigm peptide / oligonucleotide synthesis technology' (MEMTIDE) project worked on combining membrane technology with tide synthesis techniques to cost-effectively optimise quality and yield of tides while reducing batch variability. Researchers developed and optimised novel methodologies for membrane-based tide synthesis after comparing different cross-linkers, coupling agents and solvent compositions. They prepared and cross-linked integrally skinned asymmetric polybenzimidazole (PBI) nanofiltration membranes. These PBI membranes are able to withstand harsh chemical environments and can thus be used for pharmaceutical purification processes utilising acids and bases. MEMTIDE then synthesised three peptides of higher purity and yield using OH-BTL-resin with SPPS rather than Wang resin. They also tested various commercially available soluble supports to identify the most promising candidates. Scientists combined organic solvent nanofiltration (OSN) with LPPS and successfully produced the peptide 9-fluorenylmethoxycarbonyl (Fmoc)-RADA with high yield and purity. Fmoc is normally used to ensure amino acid functional group protection. This methodology required fewer equivalent amino acids for coupling when compared to SPPS. For oligonucleotide synthesis, LPPS was combined with OSN and led to the synthesis of 5-mer DNA oligonucleotides. This technique shows promise in large-scale manufacture of oligo-based therapeutics. However, certain challenges and process improvements must first be undertaken. Project activities were published in 11 papers with several more on the way and the team participated in 11 oral and 16 poster presentations at 15 international conferences. These activities have also fostered further research collaboration. Project partners have filed patents for commercial application of the processes and products developed during the project. Overall, LPPS with OSN shows promise as a technique for cost-effective scalable manufacture of peptides and oligonucleotides. Applications include peptide- and oligo-based therapies for development of designer drugs and vaccines as well as antibody and enzyme production. Besides this, technologies and processes developed could also be adapted for chemicals' manufacture, food and other industries.
Keywords
Membrane, tide synthesis, peptide, oligonucleotide, SPPS, LPPS, yield, batch variability, cross-linker, coupling agent, solvent, polybenzimidazole, nanofiltration, purification process, resin, organic solvent nanofiltration, Fmoc
