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Published on: October 31, 2013
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Protein diffusion through charged nanopores with different radii at low ionic strength.
Pieter Stroeve1, Masoud Rahman, Lekkala Dev Naidu
1Department of Chemical Engineering and Materials Science, University of California Davis, Davis, CA 95616, USA. pstroeve@ucdavis.edu.
Physical Chemistry Chemical Physics : PCCP
|September 6, 2014
Summary
Electrostatic interactions significantly hinder protein transport through nanoporous charged membranes, even at large pore sizes. This finding is crucial for optimizing protein separation processes.
Area of Science:
- Biophysics
- Materials Science
- Chemical Engineering
Background:
- Understanding protein transport through nanoporous membranes is vital for separation technologies.
- Electrostatic interactions play a complex role in protein diffusion within charged pores.
Purpose of the Study:
- To investigate the diffusion of bovine serum albumin (BSA) and bovine haemoglobin (BHb) through charged nanoporous membranes.
- To quantify the impact of pH and pore diameter on protein transport and electrostatic interactions.
Main Methods:
- Studied protein diffusion at low ionic strength across membranes with varying pore radii.
- Analyzed the effects of solution pH and membrane pore diameter on pore permeability.
- Employed a two-region pore model and approximated equations for protein and pore charge dependence.
Main Results:
- Both surface and bulk diffusion occurred simultaneously due to a large screening Debye length.
- Permeability approached bulk self-diffusion coefficients as pore diameter increased.
- Significant electrostatic hindrance was observed even for pore sizes much larger than the proteins, including at their isoelectric points.
Conclusions:
- Electrostatic hindrance is a dominant factor in protein transport through charged nanoporous membranes, irrespective of pore size relative to the protein.
- The findings provide valuable insights for the design of advanced protein separation processes.
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