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Theory of macromolecular transport through protein channels and nanopores
Published on Nov 05, 20124213 Views
An understanding of the ubiquitous phenomenon of translocation of electrically charged macromolecules through narrow channels requires an adequate description of polyelectrolyte dynamics, electrolyte
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Theory of macromolecular transport through protein channels and nanopores00:00
Applicability of General Concepts from Polymer Physics? (1)02:05
Applicability of General Concepts from Polymer Physics? (2)05:57
The Road to the $1,000 Genome07:43
Polymer Translocation08:35
Single-file single molecule translocation11:41
Typically13:26
Significant entropy15:00
Pores are complex too16:32
Hydrodynamics17:14
Entropic Barrier Model (1)20:30
Nucleation and Growth21:45
Entropic Barrier Model (2)23:13
Free Energy of a Tethered Polymer24:10
DYNAMICS25:08
Translocation is Drift-Diffusion, after Nucleation27:57
Single-file single molecule translocation28:45
α-hemolysin channel30:29
Langevin Dynamics31:06
Modified Poisson-Nernst-Planck (1)32:06
Modified Poisson-Nernst-Planck (2)32:57
Modified Poisson-Nernst-Planck (3)33:39
C.Y. Kong and MM, Electrophoresis34:18
Sodium polystyrene sulfonate through α-hemolysin pore35:44
Translocation of synthetic polyelectrolyte36:49
More than 90% don’t go through!37:17
Pores are charged heterogeneously38:14
C.T.A. Wong and MM, J. Chem. Phys. 133, 045101 (2010)39:15
Frequency of polymer-pore encounters40:56
Data42:26
Three Stages of Translocation44:09
1. Drir‐diffusion (1)45:35
Einstein’s equation fails!46:30
1. Drir‐diffusion (2)47:21
MM, Electrophoresis, 17, 1167 (1996)47:34
2. Capture49:08
Large capture radius in solid-state nanopores49:20
Coil stretching by electro-osmotic flow ?50:27
Potential and Charge distribution (1)51:11
Potential and Charge distribution (2)51:23
Fluid flow is continuous51:28
Results52:44
3. Barrier53:10
Entry of a polyelectrolyte with its counterions to a pore (1)53:13
Entry of a polyelectrolyte with its counterions to a pore (2)53:16
Entropic barrier decreases with chain length53:18
Puwng all three components together53:19
Drift‐diffusion + Entropic barrier for a charged polymer53:24
Conclusions54:06
Implications in Biology54:33
M. Muthukumar55:15