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 small-angle scattering (SAS) method to achieve such measurements.

Introduction

Quantitative characterization of interactions between biomolecular condensates and molecular features of the proteins encoding LLPS is essential to understand the molecular basis of biological processes. However, directly probing the dense phases of biomolecules is often technically challenging. By exploiting the symmetry between the conformational behavior of biomolecules in dilute and dense phases, details critical for phase separation can be inferred from precise measurements of the dilute phase, thus avoiding the complex characterization of the dense phase. SAS method is well suited for low-resolution (1-2 nm) molecular size and shape determination and can provide useful insights into biomolecular interaction mechanisms and conformational transitions in terms of stoichiometry and alignment.

Fig. 1. The SAXS patterns of suspected interacting biomolecules are analyzed to characterize the interaction fraction. (Allec N, et al., 2015)

Customized Services

Symmetry between dilute and dense phases exists in the overall size and shape of biomolecular conformations. CD BioSciences offers the useful SAS method to characterize biomolecular condensates in the size range of 1 nm-1 μm and to provide useful structural information in the form of molecular envelopes. Our advanced SAS method makes it possible to accurately characterize samples of essentially disordered protein regions at concentrations low enough to avoid the interference of intermolecular attraction, oligomerization or aggregation.

Here, we offer a small-angle X-ray scattering (SAXS) method to characterize conformational changes within biomolecules in monodisperse solutions as well as binding events between biomolecules. This method has better resolution than dynamic light scattering (DLS), and is able to detect changes in the compaction state of polymers. In addition, we use size exclusion chromatography (SEC) in combination with SAXS (SEC-SAXS) to eliminate aggregates from the sample immediately prior to data collection.

We are proud to place the SAXS measurements in the framework of LLPS theory:

✓ Resolving structural information from SAXS.

✓ Complications of SAXS measurements of self-assembled proteins.

✓ Measurement of IDR samples in SEC-SAXS mode.

✓ Raw data analysis.

✓ Synchrotron SAXS beamline hardware.

✓ Model correlation analysis.

✓ Implementation of SAXS measurements of single-strand IDR behavior to characterize phase behavior.

Advantages of the Small-Angle X-ray Scattering Method

• It is a high-resolution characterization technique capable of resolving features in the 1 to 100 nm range.
• Can be used to study biological specimens in their natural environment.
• Suitable for determining the shape, size, distribution and location of various biomolecular condensates.

We provide a new method for characterizing interactions between labeled biomolecular condensates based on the scattering signature of highly scattering molecular probes. From the scattering features, information about the interaction fraction and high-resolution spatial information can be obtained. If you are interested in our services, please do not hesitate to contact us for more information.