15 research outputs found
Duality in the problems of optimal control described by first-order partial differential inclusions
Soil CO2 emission, microbial biomass, and microbial respiration of woody and grassy areas in Moscow (Russia)
Structure of human POT1 bound to telomeric single-stranded DNA provides a model for chromosome end-protection
Slowing down single-molecule trafficking through a protein nanopore reveals intermediates for peptide translocation
The microscopic details of how peptides translocate one at a time through nanopores are crucial determinants for transport through membrane pores and important in developing nano-technologies. To date, the translocation process has been too fast relative to the resolution of the single molecule techniques that sought to detect its milestones. Using pH-tuned single-molecule electrophysiology and molecular dynamics simulations, we demonstrate how peptide passage through the α-hemolysin protein can be sufficiently slowed down to observe intermediate single-peptide sub-states associated to distinct structural milestones along the pore, and how to control residence time, direction and the sequence of spatio-temporal state-to-state dynamics of a single peptide. Molecular dynamics simulations of peptide translocation reveal the time- dependent ordering of intermediate structures of the translocating peptide inside the pore at atomic resolution. Calculations of the expected current ratios of the different pore-blocking microstates and their time sequencing are in accord with the recorded current traces