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Release of lysozyme from the branched polyelectrolyte-lysozyme complexation
Ran Ni1, Dapeng Cao, Wenchuan Wang
1Division of Molecular and Materials Simulation, Key Lab for Nanomaterials, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China.
The Journal of Physical Chemistry. B
|March 18, 2008
Summary
Lysozyme release from polyelectrolyte complexes is controlled by salt concentration and pH. Optimal salt conditions prevent protein self-association, crucial for biological applications.
Area of Science:
- Biomaterials Science
- Polymer Chemistry
- Protein Chemistry
Background:
- Polyelectrolyte-protein complexes are widely studied for applications in drug delivery and biomaterials.
- Understanding the release mechanisms of proteins from these complexes is crucial for controlling their functionality.
- Lysozyme, a model protein, is often used to investigate protein-polyelectrolyte interactions.
Purpose of the Study:
- To investigate the release behavior of lysozyme from branched polyelectrolyte complexes.
- To determine the effects of salt ionic strength and pH on complex stability and protein release.
- To explore the influence of polyelectrolyte architecture on protein release dynamics.
Main Methods:
- Utilizing a discretely charged sphere model for lysozyme.
- Systematically varying salt concentration and pH of the solution.
- Analyzing protein release and self-association phenomena.
- Calculating the second virial coefficient to assess protein dispersion.
Main Results:
- Increasing salt ionic strength gradually releases lysozyme due to electrostatic screening, with a critical strength for complete dissociation.
- Beyond critical salt concentration, released lysozyme undergoes detrimental self-association.
- Optimal salt concentration for protein dispersion coincides with the critical ionic strength, maximizing the second virial coefficient.
- Increasing pH also induces lysozyme release by altering lysozyme's charge and weakening polyelectrolyte-mediated attraction.
- Protein release is more challenging from branched polyelectrolytes compared to linear ones.
Conclusions:
- Salt ionic strength and pH are key parameters controlling lysozyme release from branched polyelectrolyte complexes.
- A critical salt concentration exists for complete complex dissociation, and this concentration also optimizes protein dispersion.
- Branched polyelectrolyte architecture influences the ease of protein release, making it more difficult than from linear counterparts.
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