Related Experiment Video
Updated: Mar 17, 2026
10:20
Single-Molecule Tracking Microscopy - A Tool for Determining the Diffusive States of Cytosolic Molecules
Published on: September 5, 2019
8.9K
Concentration-dependent changes in apparent diffusion coefficients as indicator for colloidal stability of protein
Katharina Christin Bauer1, Mathias Göbel1, Marie-Luise Schwab1
1Institute of Process Engineering in Life Sciences, Section IV: Biomolecular Separation Engineering, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.
International Journal of Pharmaceutics
|July 17, 2016
Summary
The apparent diffusion coefficient predicts protein aggregation and viscosity in biopharmaceutical solutions. This parameter offers a prognostic tool for maintaining colloidal stability during production and storage.
Area of Science:
- Biopharmaceutical Science
- Protein Chemistry
- Colloid Science
Background:
- Colloidal stability is critical for biopharmaceutical production, impacting downstream processing, formulation, and storage.
- Understanding protein aggregation and high viscosity is essential for maintaining product quality and process efficiency.
- Current methods for assessing colloidal stability can be complex and may not provide real-time insights.
Purpose of the Study:
- To correlate changes in the apparent diffusion coefficient with protein aggregation and dynamic viscosity.
- To evaluate the apparent diffusion coefficient as a prognostic tool for colloidal stability.
- To investigate the influence of protein type, concentration, pH, and NaCl on protein interactions and stability.
Main Methods:
- Studied model proteins: α-lactalbumin, lysozyme, and glucose oxidase.
- Measured apparent diffusion coefficient, protein phase behavior, and dynamic viscosity.
- Varied protein concentration, pH, and NaCl concentration to simulate different processing conditions.
Main Results:
- Changes in apparent diffusion coefficient mirrored variations in protein interactions across different conditions.
- Stable, low-viscosity samples exhibited near-linear diffusion coefficient dependence.
- Deviations from linearity indicated increased viscosity and aggregation probability, independent of protein type.
Conclusions:
- The apparent diffusion coefficient serves as a sensitive indicator of colloidal instability in protein solutions.
- This parameter can predict protein aggregation and viscosity, acting as a prognostic tool.
- Monitoring the apparent diffusion coefficient offers a simplified approach to ensuring biopharmaceutical product stability.
Related Concept Videos
01:24Protein Diffusion in the Membrane
6.1K
Proteins show rotational as well as lateral diffusion across the membrane. The lateral diffusion of proteins was confirmed through the cell fusion experiment where mouse and human cells were fused, resulting in hybrid cells. When the human and mouse cells fused, the specific membrane proteins on human and mouse cells were marked with the red and green-fluorescent markers, respectively. Initially, the red and green fluorescence was located on the respective hemisphere of the cell. As time...
6.1K
01:19Protein Dynamics in Living Cells
2.8K
Different fluorescence-based techniques are used to study the protein dynamics in living cells. These techniques include FRAP, FRET, and PET.
Fluorescent recovery after photobleaching (FRAP) is a fluorescent-protein-based detection technique used to quantify protein movement rates within the cell. This method exposes a small portion of the cell to an intense laser beam. The laser beam causes permanent photobleaching of the fluorophore-tagged proteins in the exposed region. As the bleached...
Fluorescent recovery after photobleaching (FRAP) is a fluorescent-protein-based detection technique used to quantify protein movement rates within the cell. This method exposes a small portion of the cell to an intense laser beam. The laser beam causes permanent photobleaching of the fluorophore-tagged proteins in the exposed region. As the bleached...
2.8K
01:29The Colloidal State
83
The formation of a colloidal system is exemplified by an aqueous solution containing Cl− ions is introduced to another containing Ag+ ions, resulting in the precipitation of solid AgCl as extremely tiny crystals. Instead of settling out as a filterable precipitate, these crystals remain suspended in the liquid, showcasing a colloidal system.A colloidal system involves colloidal particles within the approximate range of 1 to 1000 nm in at least one dimension, dispersed in a medium called...
83