Distinguishing endothelin 1 (ET-1) from endothelin 2 (ET-2) using a FraC
nanopore. (a) The translocation data of ET-2 and ET-2 revealed distinguishable
fractional blockade current (IB) at 0.089 for ET-1 and 0.061 for
ET-2. (b) By adding ET-1 and ET-2 consecutively to the same pore, two distinct
populations were observed by plotting the event amplitude standard deviation
(in) over the corresponding IB. (c) ET-1 and ET-2 are
two nearly isomeric polypeptides differing from each other by 1 amino acid out
of 21 as well as the position of a leucine residue (leucine 6 in ET-1 and
leucine 7 in ET-2). Adapted with permission from G. Huang, K. Willems, M.
Soskine, C. Wloka, and G. Maglia, Nat. Commun., 2017, 8, 935,
under Creative Commons Attribution 4.0 International license, Nature
Publishing.