Subnucleosomal Particle Preparation Service

Inquiry

Dynamic intermediates of chromatin, such as hexanuclear and tetranuclear bodies, are crucial for understanding fundamental processes like transcription and DNA repair. CD BioSciences offers specialized subnucleosomal particle preparation services, providing structurally well-defined and compositionally pure particles as precise molecular tools for mechanism discovery. Our platform supports full customization, from histone variants and PTMs to specific DNA sequences, ensuring your particle is tailored to answer your unique biological question.

Introduction to Subnucleosomal Particle

Beyond the canonical nucleosome, chromatin dynamics are driven by transient, non-canonical intermediates such as hexasomes (lacking one H2A-H2B dimer) and tetrasomes (comprising only the H3-H4 tetramer). These subnucleosomal particles are not mere byproducts but are crucial functional states that arise during transcription, replication, and DNA repair. Studying their distinct structures, stabilities, and protein interactions is essential for a mechanistic understanding of chromatin remodeling, histone exchange, and epigenetic regulation. Access to homogeneous, well-defined subnucleosomal particles is therefore a critical prerequisite for advancing from phenomenological observation to precise biochemical and biophysical dissection of these dynamic processes.

The subnucleosomal genomic architecture reveals unique nucleosome folding motifs.

Fig.1 The subnucleosomal genome structure revealed unique nucleosome folding motifs. (Ohno M, et al., 2019)

Our Services

To overcome the challenge of heterogeneity, CD BioSciences provides specialized subnucleosomal particle preparation services. We employ a controlled, stepwise assembly strategy to produce structurally homogeneous and compositionally defined hexasomes and tetrasomes. By precisely controlling histone composition (including variants and PTMs) and DNA geometry, we generate these non-canonical particles not as heterogeneous mixtures, but as idealized model systems. This enables rigorous investigation into the mechanisms of chromatin remodelers, the functional specificity of histone variants, and the dynamic principles governing nucleosome stability and disassembly.

Customized Solutions for Subnucleosomal Particle Preparation

Our service delivers precisely engineered subnucleosomal particles through a controlled stepwise assembly strategy, serving as defined molecular tools for dissecting chromatin dynamics. This core technical path abandons random enzymatic stripping in favor of building target particles from the ground up: we first prepare high-purity core components (such as PTM-defined H3-H4 tetramers) and then precisely control the conditions for adding or omitting H2A-H2B dimers to directly reconstitute the desired hexasomes or tetrasomes. We offer preparation of the following key particle types, each fully customizable to your specific research needs.

Particle Type	Core Composition	Key Research Applications
Hexasome	A (H3-H4)₂ tetramer wrapped with one H2A-H2B dimer, assembled on ~110-130 bp of DNA.	Mechanistic studies of H2A-H2B dimer deposition/eviction Activity assays for chromatin remodelers (e.g., SWI/SNF) that catalyze dimer displacement Functional analysis of histone variants (e.g., H2A.Z, macroH2A) in a semi-nucleosomal context Single-molecule investigations of partial nucleosome disassembly and stability
Tetrasome	A (H3-H4)₂ tetramer wrapped on ~80-100 bp of DNA, lacking both H2A-H2B dimers.	Fundamental studies of nucleosome assembly/disassembly pathways Biophysical analysis of H3-H4 tetramer dynamics and DNA wrapping mechanics Precursor for asymmetric or hybrid nucleosome assembly Interaction studies with histone chaperones (e.g., Asf1, CAF-1) specific for H3-H4
Customized Particle	Bespoke compositions including specific histone variants (e.g., CENP-A, H3.3), PTM patterns, non-natural amino acids, or specialized DNA sequences (e.g., curved DNA, modified bases).	Modeling specialized chromatin states (e.g., centromeric, telomeric) PTM-dependent interaction analysis with readers, writers, and erasers Crosslinking/MS studies to map protein interactions on defined subcomplexes High-resolution structural studies (Cryo-EM) of variant-specific architectures Drug discovery screens targeting unique interfaces of non-canonical particles

Workflow of Subnucleosomal Particle Preparation Service

Diverse Application Scenarios

Single-Molecule Studies of Chromatin Remodeling Mechanisms: Utilize well-defined hexasomes as substrates to directly visualize and quantify the real-time dynamics of H2A-H2B dimer eviction by remodelers like SWI/SNF.
Functional Analysis of Histone Chaperones: Employ tetrasomes or hexasomes to dissect the specificity and kinetics of chaperone-mediated histone recognition, transfer, and deposition in nucleosome assembly/disassembly pathways.
High-Resolution Structure Determination: Provide homogeneous hexasome and tetrasome particles as ideal samples for Cryo-EM and other structural biology techniques to resolve atomic details of non-canonical chromatin states.
Dynamic Nucleosome Editing & Engineering: Use these core particles as standardized building blocks to programmatically assemble asymmetric, hybrid, or higher-order chromatin structures for synthetic biology applications.

Our Advantages

Structural Fidelity: Provide structurally homogeneous particles that closely mimic native states, not heterogeneous mixtures.
Exceptional Stability & Reproducibility: Ensure highly consistent batch-to-batch quality through optimized processes.
Flexible Customization: Support a wide range of designs, from basic particles to highly complex, customized assemblies.
Cross-Disciplinary Compatibility: Deliver products compatible with various cutting-edge platforms, including single-molecule techniques, structural biology, and biochemical assays.

Understanding chromatin dynamics requires tools that capture its essential intermediates with precision. At CD BioSciences, our subnucleosomal particle preparation service is dedicated to providing these critical, well-defined tools (e.g., homogeneous hexasomes and tetrasomes) to illuminate the mechanisms of remodeling, chaperoning, and epigenetic regulation. By combining rigorous assembly control with deep scientific partnership, we empower researchers to build a definitive experimental foundation. If you are interested in our services, please feel free to contact us for more details and quotation information of related services.

Reference

1. Ohno M, Ando T, Priest D G, et al. Sub-nucleosomal genome structure reveals distinct nucleosome folding motifs[J]. Cell, 2019, 176(3): 520-534. e25.