Nanopore paper Xing et al 2023

Question 1

What is a nanopore?

Answer 1

Nanopores are nanoscale holes within a thin membrane and allow transport of molecular cargo from either side of the membrane.

The passage ofanalyte molecules through the nanopore temporarily blocks the flow ofions which causes acharacteristic signal inthe measured current

Question 2

What are the main characteristics of protein pores?

Answer 2

• multiunit transmembrane channel protein forming water filled lumen which passes through the membrane
• biological protein expression enables the large-scale fabrication of nanopores with precise and consistent geometry
• introduction of several chemical modifications makes the fabrication of pores of predictable structure difficult
  *

Question 3

What are artificial nanopores, and which types of artificial nanopores are typically used?

Answer 3

Solid-state nanopores: from inorganic thin membrane sheets by etching a hole, via electron or ion-beam drilling, or by using glass nanopipettes.

More stable.

Highly customisable lumen sizes and adjustable surface properties.

High analyte translocation velocity, inconsistent pore geometry, and lower resolution on pore chemistry than atomistic-defined protein pores => slowing translocation is required ( e.g. through nanobeads or molecular modifications)

Typically made from carbon nanotubes or 2D atomically thin MoS2
but also DNA nanostructures!!!

Tethering DNA oligonucleotides to the walls of solid state nanopores has helped mimic the characteristic current rectification of biological nanopores.

Question 4

How is it possible to insert DNA origami nanopores into lipid bilayers?

Answer 4

To achieve membrane binding and puncturing, DNA nanopore are equipped with hydrophobic modifications at selected sites within the designed nanostructure. Honeycomb lattice toform alarge DNA origami extramembrane cap structure (inspired by α-HL)

Examples of anchors:
* two porphyrin-based tetraphenyl-porphyrin (TPP) tags
* up to 46 cholesterol membrane anchors

Question 5

What are usually DNA origami nanopores used for?

Answer 5

Recently, the repertoire of gated six helix-bundle pores has been expanded for external triggers such as heat, protein binding, light and ATP binding.

Question 6

Examples of protein nanopores