Ultrafiltration, a useful method for isolation of intermediates in native chemical ligation exemplified with the total synthesis of Sortase AΔN59.

Abstract

In this paper, ultrafiltration was employed to facilitate the isolation of intermediates in native chemical ligation. Depending on the molecular weight cutoff of the membrane used, molecules with different sizes could be purified, separated, or concentrated by the ultrafiltration process. Total chemical synthesis of the polypeptide chain of the enzyme Sortase AΔN59 was used as an example of the application of ultrafiltration in chemical protein synthesis. Sortase A is a ligase that catalyzes transpeptidation reactions between proteins that have C-terminal LPXTG recognition sequence and Gly5- on the peptidoglycan of bacterial cell walls. Ultrafiltration technique facilitated synthesis of Sortase AΔN59 and was a promising tool in isolation of intermediates in native chemical ligation.