Related Experiment Video
Updated: Aug 15, 2026
09:49
Sedimentation Equilibrium of a Small Oligomer-forming Membrane Protein: Effect of Histidine Protonation on Pentameric Stability
Published on: April 2, 2015
Analysis of protein fouling during ultrafiltration using a two-layer membrane model
1Department of Chemical Engineering, University of Delaware, Newark, Delaware 19716, USA.
Biotechnology and Bioengineering
|April 1, 1999
Summary
Protein fouling of ultrafiltration membranes creates a distinct layer, impacting membrane performance. This study reveals filtration-formed layers are denser than adsorbed ones, with increasing thickness over time.
Area of Science:
- Membrane science and technology
- Biomaterials and surface science
- Chemical engineering
Background:
- Protein fouling significantly impacts ultrafiltration (UF) membrane performance, altering flux and retention.
- The precise nature and structure of the protein fouling layer remain debated.
- Understanding fouling mechanisms is crucial for optimizing UF processes.
Purpose of the Study:
- To investigate the characteristics of protein fouling layers on polyethersulfone (PES) UF membranes.
- To differentiate the effects of static adsorption versus dynamic filtration on fouling layer formation.
- To elucidate the impact of fouling on membrane transport properties.
Main Methods:
- Utilized polyethersulfone ultrafiltration membranes.
- Measured hydraulic permeability and dextran sieving coefficients before and after albumin exposure.
- Analyzed dextran molecular weight distributions using gel permeation chromatography (GPC).
- Applied a two-layer membrane model for data analysis.
Main Results:
- Protein fouling significantly reduced dextran sieving coefficients, affecting both diffusive and convective transport.
- The fouling layer formed during filtration was more tightly packed than that from static adsorption.
- Calculations indicated constant protein layer pore size but increasing thickness with exposure time.
Conclusions:
- Protein fouling layer structure depends on the formation mechanism (adsorption vs. filtration).
- Fouling layer thickness increases with exposure time, while pore size remains relatively constant.
- Findings offer critical insights into protein fouling dynamics in ultrafiltration.
Related Concept Videos
01:19Fluid Mosaic Model
Scientists identified the plasma membrane in the 1890s and its principal chemical components (lipids and proteins) by 1915. The model for plasma membrane structure, proposed in 1935 by Hugh Davson and James Danielli, was the first model to be widely accepted in the scientific community. The model was based on the plasma membrane's "railroad track" appearance in early electron micrographs. Davson and Danielli theorized that the plasma membrane's structure resembled a sandwich with the analogy of...
01:18Detergent Purification of Membrane Proteins
Detergents are used to purify the integral proteins of the membrane. The hydrophobic portion of the detergent can replace membrane phospholipids while solubilizing the membrane proteins. When detergent monomers reach a specific concentration in a solution called critical micelle concentration (CMC), they form micelles. Above CMC, the concentration of the detergent monomers remains in equilibrium with the micelle. The number of detergent monomers present in the CMC varies for each detergent, and...
01:24Protein Diffusion in the Membrane
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...
01:15Dialysis
Dialysis is a diffusion-based purification process that separates analyte molecules from a complex matrix. This is accomplished by allowing molecules in the solution to pass through a semipermeable membrane into a liquid on the other side. The membrane is usually made of cellulose acetate or cellulose nitrate, and the second liquid must be miscible with the solution. Ions (e.g., chloride or sodium) or organic molecules (e.g., glucose) can pass through the membrane pores, which generally have...