Organic Solvent Nanofiltration: A New Paradigm in Peptide Synthesis

Abstract

Solid-phase synthesis is the dominant paradigm for peptide synthesis, used ubiquitously from discovery to production scale. However, the solid-phase approach produces coupling steps that may not be quantitative, introducing errors in amino acid sequences. It also entails an excess of reagents to overcome mass transfer limitations and restrictions on solvent, coupling chemistry, and protecting groups. Organic solvent nanofiltration (OSN) is a newly emerging technology capable of molecular separations in organic solvents. This contribution reports a new technology platform which advantageously combines OSN with solution-phase peptide synthesis, Membrane Enhanced Peptide Synthesis (MEPS). A first amino acid is linked to a soluble polyethylene glycol anchor. Through subsequent repeated coupling and deprotection steps, the peptide is extended to the desired length. The residual byproducts and excess reagents after each reaction are removed by diafiltration through a solvent-stable membrane which retains the peptide. Two pentapeptides are produced using this new technology. The purity of the peptides produced by MEPS is higher than that of peptides produced by solid-phase synthesis, under the same conditions. This illustrates clearly that MEPS benefits from the advantages of solution-phase synthesis, while avoiding the purification steps that have until now made solution-phase synthesis practically difficult.

Implication of Side Reactions in Iterative Biopolymer Synthesis: The Case of Membrane Enhanced Peptide Synthesis

“…14 Membrane enhanced peptide synthesis (MEPS) improves the LPPS route by replacing extraction, precipitation, microfiltration and drying with diafiltration [15][16][17][18] , and has the advantage of significantly shorter processing time. 19,20 Previous studies have shown that this iterative approach can achieve high yield and purity for peptide, oligonucleotide and mono-disperse polyethylene glycol (PEG). [21][22][23] The following manuscript should be cited as: Wenqian Chen, Mahdi Sharifzadeh*, Nilay Shah, and Andrew G. Livingston.…”

Ultrathin free-standing membranes from metal hydroxide nanostrands

“…Solvent-resistant nanofiltration membranes with superior separation properties are also in high demand for the production of biopolymers and biodiesel [157,158]. In recent years, enormous quantities of oilcontaminated water have been produced in oil and gas fields, and the recycling of this water (so-called produced water) represents another important application for solvent-resistant filtration membranes.…”

Organic Solvent Nanofiltration (OSN): A New Technology Platform for Liquid-Phase Oligonucleotide Synthesis (LPOS)

“…Thus SPOS requires a higher excess of the expensive monomers to drive coupling to completion than would be required in solution phase. Secondly, the intensity of SPOS is restricted by sub-maximal loading of the polymeric support to minimize interference between neighboring chains (particularly when preparing longer oligos), and thus maintain coupling efficiency 15 . Thirdly, the SPOS process is highly mass intensive at large scale 6 .…”