Multi-wavelength analytical ultracentrifugation of biopolymer mixtures and interactions
Challenge
Interactions between biopolymers play a vital role in
various biological processes, and their study is paramount in understanding metabolic,
developmental, and regulatory mechanisms
While various methods exist to study
macromolecular interactions, such as x-ray crystallography, mass spectrometry, and surface
plasmon resonance, they come with limitations. For instance, some don't allow for studying
molecules in a solution state where dynamic properties like reversible association can be
adjusted, others necessitate the binding of molecules to solid supports, and some require
excessive sample amounts or lack resolution for complex interactions.
Solution
To address these limitations, multi-wavelength
analytical ultracentrifugation (MW-AUC) was introduced.
This method allows the study of biopolymer interactions
in conditions mimicking physiological environments, including changes in pH, ionic strength,
and redox potential.
MW-AUC provides an avenue to titrate drugs and other
molecules to observe their interactions reversibly. By leveraging unique chromophores and
their extinction profiles, MW-AUC can obtain information from an additional spectral
dimension.
The method has seen iterative improvements
since its inception: in 2008, the integration of a UV-visible multi-wavelength detector to
the analytical ultracentrifuge added an optical dimension, in 2015 the optical system was
further refined, and by 2018, advancements like "Cölfen optics" augmented the method's
precision. The Optima AUC™ series, released in 2016 by Beckman-Coulter, further modernized
the field with the integration of interference optics and multi-wavelength absorption
optics.
Conclusion
MW-AUC emerges as a versatile and enhanced solution to
the challenges of studying biopolymer interactions. It provides improved accuracy and
flexibility over traditional methods, allowing for more nuanced studies in physiological
conditions.
The various improvements and additions to the method,
such as the Cölfen optics and Beckman optics, have further expanded its potential
applications and reliability.
Guidance on using these systems, their pros
and cons, and recommendations for experimental designs ensure that researchers can leverage
the benefits of MW-AUC to its fullest potential in understanding intricate biopolymer
interactions.
