Amino acid discrimination in a nanopore and the feasibility of sequencing peptides with a tandem cell and exopeptidase

Abstract

In polymer sequencing with a nanopore multiple discriminators may be used to distinguish among more monomers than usual. This leads to a proposal to sequence peptides using a tandem cell (RSC Adv., 2015, 5, 167–171) with exopeptidase. A Fokker–Planck model of the device shows that the 20 amino acids display a well-defined ordering, and that, in theory, several necessary conditions for effective sequencing are satisfied. Other factors, such as the role of solution pH, exopeptidase cleaving efficiency, and modified amino acids, are discussed. If validated experimentally this approach could lead to an alternative to mass spectrometry.