Related Experiment Video
Updated: Sep 15, 2025
08:21
Sample Preparation in Quartz Crystal Microbalance Measurements of Protein Adsorption and Polymer Mechanics
Published on: January 22, 2020
13.7K
Backbone Rigidity Encodes Universal Viscoelastic Signatures in Biomolecular Condensates
Sean Yang1, Subhadip Biswas1, Davit A Potoyan1,2
1Department of Chemistry, Iowa State University, Ames IA 50011, USA.
Biorxiv : the Preprint Server for Biology
|July 15, 2025
Summary
Introducing chain rigidity into models of intrinsically disordered proteins accurately predicts biomolecular condensate viscoelasticity. This advance reveals how sequence dictates material properties and elastic behavior, crucial for understanding cellular organization.
Area of Science:
- Biophysics
- Soft Matter Physics
- Molecular Biology
Background:
- Biomolecular condensates possess diverse viscoelastic properties influenced by molecular sequence and composition.
- Coarse-grained models of intrinsically disordered proteins (IDPs) are vital for studying condensate structure and thermodynamics.
- Existing flexible chain models often fail to capture complex viscoelasticity, predicting only viscous behavior.
Purpose of the Study:
- To develop a coarse-grained model that accurately reproduces the viscoelastic properties of experimentally characterized condensates.
- To investigate the role of sequence-dependent chain rigidity in determining condensate viscoelasticity.
- To establish a universal correlation for the frequency-dependent loss factor in IDP condensates.
Main Methods:
- Development of coarse-grained molecular models incorporating sequence-dependent chain rigidity for intrinsically disordered proteins.
- Simulation and analysis of condensates formed by A1-LCD and its mutants.
- Calculation of elastic and viscous moduli and frequency-dependent loss factors.
- Correlation analysis between chain rigidity, gyration radius, and viscoelastic properties.
Main Results:
- The model with sequence-dependent chain rigidity accurately reproduces experimental elastic and viscous moduli for A1-LCD condensates.
- A single parameter universally correlates the frequency-dependent loss factor with viscosity across various sequences and model variations.
- Increased chain rigidity, evidenced by a larger gyration radius, expands the elastic regime of condensates.
- Sequence rearrangements promoting sticker cluster formation were shown to tune viscoelasticity.
Conclusions:
- Sequence-dependent chain rigidity is essential for accurately modeling the viscoelastic behavior of biomolecular condensates.
- The study provides a framework for understanding and predicting sequence-encoded viscoelasticity in intrinsically disordered protein condensates.
- This approach offers insights into the microscopic origins of material properties and their regulation in cellular compartments.
Related Concept Videos
01:15Relation between Poisson's ratio, Modulus of Elasticity and Modulus of Rigidity
332
Deformation occurs in axial and transverse directions when an axial load is applied to a slender bar. This deformation impacts the cubic element within the bar, transforming it into either a rectangular parallelepiped or a rhombus, contingent on its orientation. This transformation process induces shearing strain. Axial loading elicits both shearing and normal strains. Applying an axial load instigates equal normal and shearing stresses on elements oriented at a 45° angle to the load axis.
332
01:16IR Spectroscopy: Hooke's Law Approximation of Molecular Vibration
1.7K
A covalently bonded heteronuclear diatomic molecule can be modeled as two vibrating masses connected by a spring. The vibrational frequency of the bond can be expressed using an equation derived from Hooke's law, which describes how the force applied to stretch or compress a spring is proportional to the displacement of the spring. In this case, the atoms behave like masses, and the bond acts like a spring.
According to Hooke's law, the vibrational frequency is directly proportional to...
According to Hooke's law, the vibrational frequency is directly proportional to...
1.7K
01:15Mechanisms of Membrane-bending
2.8K
The living membranes are flexible due to their fluid mosaic nature; however, their bending into different shapes is an active process regulated by specific lipids and proteins. The membrane bending can be transient as seen in vesicles or stable for a long time as in microvilli. Cells regulate the size, location, and duration of the membrane curvature.
Membrane bending can happen due to intrinsic changes in lipid composition or extrinsic association with different proteins. The proteins involved...
Membrane bending can happen due to intrinsic changes in lipid composition or extrinsic association with different proteins. The proteins involved...
2.8K
01:15¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
1.2K
The axial and equatorial protons in cyclohexane can be distinguished by performing a variable-temperature NMR experiment. In this process, except for one proton, the remaining eleven protons are replaced by deuterium. The deuterium substitution avoids the possible peak splitting caused by the spin-spin coupling between the adjacent protons. The remaining proton flips between the axial and equatorial positions.
1.2K
00:52¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
920
At room temperature, the chair conformer of cyclohexane undergoes rapid ring flipping between two equivalent chair conformers at a rate of approximately 105 times per second. These two chair conformers are in equilibrium. The rapid ring flipping results in the interconversion of the axial proton to an equatorial proton and an equatorial to the axial proton. Such interconversions are too rapid and cannot be detected on the NMR timescale. Hence, the NMR spectrometer cannot distinguish between the...
920
01:12Adaptability of Cytoskeletal Filaments
3.9K
The cytoskeleton is a complex dynamic structure performing varied functions based on cellular requirements. The adaptability of the individual filaments in the cytoskeleton determines their ability to perform various functions within the cell. It can undergo rapid reorganization during processes like cell division or remain stable for several hours as in the interphase. The adaptability of these filaments depends on stringent regulatory mechanisms. The microfilament and microtubules of the...
3.9K