Superposition of an AC field improves the discrimination between peptides in nanopore analysis. Issue 14 (20th February 2015)

• Record Type: Journal Article
• Authors: Jakova, Elisabet; Lee, Jeremy S.
• Is Part Of: Analyst. Volume 140:Issue 14(2015)
• Page Start: 4813
• Page End: 4819
• Publication Date: 2015-02-20
• Subjects: Chemistry, Analytic -- Periodicals; 543
• DOI: 10.1039/c4an02180k
• Languages: English
• ISSNs: 0003-2654

Abstract

Abstract : There are three types of events when a peptide interacts with the pore. The AC field causes the peptide to oscillate at the entrance to the pore which can alter the type of event. Abstract : In standard nanopore analysis a constant DC voltage is used to electrophoretically drive small molecules and peptides towards a pore. Superposition of an AC voltage at particular frequencies causes molecules to oscillate as they approach the pore which can alter the event parameters, the blockade current ( I ) and blockade time ( T ). Four peptides with similar structures were studied. Alpha-helical peptides A10 (FmocDDA10 KK), A14, A18 and retro-inverso A10. It was shown that the ratio of translocations to bumping events could be manipulated by a combination of AC voltages and frequencies. In particular, A10 could be studied without interference from retro-inverso A10. Similarly, a large, intrinsically disordered protein of 140 amino acids, α-synuclein, which translocates the pore readily in a DC field could be prevented from doing so by application of an AC field of 200 mV at 100 MHz.