CD BioSciences has scattering methods of electromagnetic radiation at different wavelengths to characterize the morphology, size, and hydrodynamic radius of biomolecular condensates undergoing liquid-liquid phase separation (LLPS), on length scales of tens of angstroms to microns. Here, we provide a convenient static light scattering (SLS) method to achieve such measurements.

Introduction

LLPS has emerged as an important biological mechanism for the sequestration of macromolecules, such as proteins and nucleic acids, into cellular membraneless organelles. Unstructured and intrinsically disordered structural domains are known to facilitate multivalent interactions driving protein LLPS. SLC is a technique in physical chemistry that measures the intensity of scattered light to obtain the molecular weight and size of macromolecules such as polymers or proteins in solution. In contrast to dynamic light scattering, this technique averages the intensity of the scattered signal over time and gives the average intensity of the population. This data can then be used to determine the molecular size and, if the instrument is properly calibrated, the molecular weight of the suspended particles.

Fig. 1. Schematic of an apparatus for measurement of static light scattering. (Minton A P, 2016)

Customized Services

The scattering intensity of small molecules is proportional to the square of their molecular weight. Based on a cutting-edge scattering technology platform, CD BioSciences offers the non-invasive SLS method to determine the size, short-term diffusion coefficient, apparent size, and kinetics of protein aggregate formation over time of biomolecular condensates undergoing LLPS.

In addition, our expert team is developing SLS to map the phase of biomolecular condensates. This strategy allows measuring coexistence sites around high temperature critical regions using sample volumes as low as 10 μL and quantitatively characterizing LLPS by plotting free energy versus local minima of biomolecule concentration. Attracting customers, CD BioSciences offers a combination of DLS and SLS to characterize the two-node and spin-node distributions of phase separation systems, especially for elastin phase separation systems.

✓ DLS is used to determine the binodal profile of the phase diagram (sub-stable region) by monitoring changes in the hydrodynamic radius of the soluble complex.

✓ SLS is used to measure the defined spin nodal profile (unstable/stratified region).

Note: Here, the inverse of the measured scattering intensity is plotted as a function of temperature, and the spin nodal line temperature is determined by extrapolating to the infinite scattering intensity.

Our SLS strategy allows absolutely accurate determination of the molar mass and state of association of various biomolecular condensates and can provide much new information on protein-protein interactions, stability, and the equilibrium and kinetics of biochemical reactions in dilute solutions. If you are interested in our services, please do not hesitate to contact us for more information.