Theory and Practice of CG-MALS Book Chapter
Curious to learn how light scattering provides label-free, immobilization-free, first-principles characterization of macromolecular interactions? Download this open-access publication!
Protein Interactions, J. Cai and R.E. Wang (ed.), InTech, 2012
By Daniel Some and Sophia Kenrick
Macromolecular interactions play key roles in a host of scientific and biotechnological studies—from basic biomolecular research to protein therapeutic R&D. Light scattering measurements quantify these phenomena without tagging, immobilization, or other sample modifications that can potentially skew the interaction of interest. Composition Gradient Multi-Angle static Light Scattering (CG-MALS) and Composition-Gradient Dynamic Light Scattering (CG-DLS) determine a variety of quantitative interaction parameters, including equilibrium dissociation constants (KD), stoichiometry, virial coefficients (A2) and reaction rates. Recent advances in instrumentation and technique simplify and automate measurements, resulting in hands-off operation with excellent repeatability.
The first half of the chapter reviews the theory and practice of CG-MALS and CG-DLS. The second half focuses on a range of applications, including:
- Protein self-association as a function of ionic strength, pH, and other excipients
- Hetero-association between two proteins with various stoichiometries
- Self-assembly of multivalent protein complexes
- Dissociation kinetics
- Nonspecific attractive and repulsive interactions