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A Package of Established Analytical Tools to Investigate the Solid-State Alteration of Lipid-Based Excipients
Published on: August 9, 2022
Protein phase behavior and crystallization: effect of glycerol
H Sedgwick1, J E Cameron, W C K Poon
1Scottish Universities Physics Alliance (SUPA), School of Physics, The University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, Scotland.
The Journal of Chemical Physics
|October 2, 2007
Summary
Adding glycerol to protein solutions requires more salt for crystallization, indicating altered protein interactions. Glycerol
Area of Science:
- Protein crystallization
- Biophysical chemistry
- Solution thermodynamics
Background:
- Glycerol is a common additive for protein stabilization in aqueous solutions.
- Understanding glycerol's impact on protein crystallization is crucial for biopharmaceutical development.
- Previous studies suggest glycerol alters protein-protein interactions.
Purpose of the Study:
- To investigate the effect of varying glycerol concentrations on lysozyme crystallization from brine.
- To quantitatively model the influence of glycerol on interprotein interactions.
- To determine if glycerol's effects can be explained by changes in solvent properties.
Main Methods:
- Crystallization experiments of lysozyme in aqueous solutions with up to 40 wt% glycerol and varying salt concentrations.
- Modeling of interprotein interactions using the Derjaguin-Landau-Verwey-Overbeek (DLVO) potential.
- Quantification of interprotein interactions via the second virial coefficient (B(2)).
Main Results:
- Increased glycerol concentration necessitated higher salt concentrations for lysozyme crystallization.
- The Derjaguin-Landau-Verwey-Overbeek (DLVO) potential successfully modeled the observed interprotein interactions.
- Glycerol's effects were fully explained by its modification of the solvent's dielectric constant and refractive index.
- A universal crystallization boundary was identified for all glycerol concentrations when interprotein interactions were quantified by the second virial coefficient (B(2)).
Conclusions:
- Glycerol significantly alters the conditions required for lysozyme crystallization by modifying solvent properties.
- The Derjaguin-Landau-Verwey-Overbeek (DLVO) potential provides a robust framework for understanding glycerol's impact on protein interactions.
- The concept of a universal crystallization boundary, based on quantified interprotein interactions, offers a new perspective on protein crystallization in the presence of additives.
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