Revisiting abnormal slow translocation of ssDNA through the 2.3 nm wide gamma-hemolysin nanopore

Abstract

Biological nanopores have been used extensively in biomolecule sensing, especially in sequencing DNA and protein. The wildly studied three biological nanopores are α-hemolysin, MspA, and Aerolysin, whose constriction zones are 1.4 nm, 1.2 nm, and 1.0 nm, respectively; while the translocation times of ssDNA are about 1-5 μs/nt. Interestingly, γ-hemolysin (γ-HL) protein channel with a 2.3-nm wide constriction zone can assemble into an octameric pore on a planar lipid bilayer, however, the translocation rate of ssDNA through the γ-HL pore is 16 μs/nt.