The novel membrane enhanced peptide synthesis process

Abstract

In this research project we investigated the feasibility of incorporating organic solvent nanofiltration techniques with peptide synthesis and developed the Membrane Enhanced Peptide Synthesis process – the MEPS process. Two membranes had been identified to be applicable for the MEPS process to separate the peptide building block from post reaction waste. These are the commercially available Inopor ZrO2/Al2O3 hydrophobic membrane and the cross-linked polyimide membrane that had been fabricated in our laboratory. Two penta-peptides were synthesized on a soluble polymeric support to demonstrate the principle of MEPS process. The purity and yields of these penta-peptides were excellent when compared with one synthesized using the Liquid Phase Peptide Synthesis (LPPS) and Solid Phase Peptide Synthesis (SPPS) processes. To improve the quality and supply of membrane for the MEPS process a number of membrane fabrication parameters were investigated. This investigation demonstrated ways of manipulating the performance of the cross-linked polyimide membrane which gives engineers the opportunity to tailor make polymeric membrane to meet the requirement of the MEPS process. This membrane optimisation provides the MEPS process with a constant supply of reproducible membrane and allows this process to be further developed into a highly repeatable process. Other soluble polymeric support products were also been investigated in an attempt to avoid product contamination by PEGylated waste. Peptide chains were built onto a degradable polymeric support and once the desired peptide sequence had completed, the polymeric support was then completely hydrolysed in acid to obtain a high purity peptide product. Results showed this simple idea was not as straight forward to perform as expected. It demonstrated that the idea was possible and has great potential but further development is required. A number of recommendations have been suggested for further improvement and optimisation of this newly developed MEPS process. Not only these are related to the enhancement of the membrane stability, improvement in peptide crude purity and product yield, but also other potential applications of the MEPS principle