Related Experiment Video
Updated: May 11, 2026
08:51
Monitoring Protein Adsorption with Solid-state Nanopores
Published on: December 2, 2011
Ion-specific conformational behavior of polyzwitterionic brushes: exploiting it for protein adsorption/desorption
Tao Wang1, Xiaowen Wang, Yunchao Long
1Department of Chemical Physics, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, P R China.
Langmuir : the ACS Journal of Surfaces and Colloids
|May 11, 2013
Summary
Poly(sulfobetaine methacrylate) brushes
Area of Science:
- Polymer science
- Surface chemistry
- Biomaterials
Background:
- Polymer brush conformation influences protein interactions.
- Understanding these interactions is key for biomaterial design.
Purpose of the Study:
- Investigate poly(sulfobetaine methacrylate) (PSBMA) brush conformation.
- Determine the effect of ionic strength and ion type on PSBMA brushes.
- Correlate brush conformation with protein adsorption/desorption.
Main Methods:
- Quartz crystal microbalance with dissipation (QCM-D) to monitor mass and viscoelastic changes.
- Surface plasmon resonance (SPR) to measure changes in refractive index and thickness.
- Systematic variation of ionic strength and anion/cation types.
Main Results:
- Anion effectiveness in weakening chain association and enhancing hydration depends on ionic strength (kosmotrope to chaotrope order reversed at high ionic strength).
- Chaotropic anions induce heterogeneous brush structures at higher ionic strengths.
- SPR shows no anion specificity due to insensitivity to water molecules.
- Protein adsorption is reduced by chaotropic anions; desorption is enhanced.
Conclusions:
- PSBMA brush conformation is tunable by ionic strength and anion type.
- Chaotropic anions are more effective in controlling protein adsorption/desorption.
- Cation specificity is not observed in brush conformational changes.
Related Concept Videos
02:40Ligand Binding Sites
Proteins are dynamic macromolecules that carry out a wide variety of essential processes; however, the activities of most proteins depend on their interactions with other molecules or ions, known as ligands.
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...
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...
02:04Protein-protein Interfaces
Many proteins form complexes to carry out their functions, making protein-protein interactions (PPIs) essential for an organism's survival. Most PPIs are stabilized by numerous weak noncovalent chemical forces. The physical shape of the interfaces determines the way two proteins interact. Many globular proteins have closely-matching shapes on their surfaces, which form a large number of weak bonds. Additionally, many PPIs occur between two helices or between a surface cleft and a polypeptide...