Structural biology is a cornerstone of modern life sciences and drug development. Understanding the three-dimensional structures of biological macromolecules is crucial for deciphering their functions, interactions, and roles in health and disease. Among the powerful tools available for this purpose, cryo-electron microscopy (cryo-EM) has emerged as a revolutionary technique, providing high-resolution insights into the structure and function of biomolecules.
Cryo-EM allows researchers to determine the 3D structures of biological macromolecules, such as proteins and viruses, by collecting a large number of 2D images of purified particles preserved close to their native state at ultra-low temperatures. These images are then processed using computational algorithms to reconstruct detailed 3D structural models.
Shuimu BioSciences, founded in 2017 at Tsinghua University, is highlighted as the first commercial platform in Asia offering cryo-electron microscopy structure determination services. Leveraging a deep research and technical heritage in structural biology, the company has established efficient, advanced workflows for both experimental procedures and data analysis. Shuimu BioSciences provides a range of cryo-EM services designed to accelerate structural biology research and drug development.
To learn more about how these services can benefit your research, visit https://shuimubio.com/.
Key Cryo-EM Services Offered by Shuimu BioSciences
Shuimu BioSciences offers a comprehensive suite of services centered around cryo-EM technology. These services cover various aspects of structural analysis, from sample characterization to high-resolution structure determination.
1. One-Stop SPA Solutions Single Particle Analysis (SPA) is described as a powerful approach integrating cryo-EM to reveal high-resolution 3D structures of biological macromolecules. This method involves collecting extensive 2D images and using computational algorithms for processing and reconstruction to produce a detailed 3D structural model. The advantages of cryo-EM SPA include preserving samples close to their native state, capturing diverse conformations, requiring minimal sample volume, and determining heterologous protein complexes. Shuimu's One-Stop SPA Solution covers a wide range of sample types, including antigen-antibody complexes, small molecules & targets, PROTACs, membrane proteins (GPCRs, ion channels, transporters), VLPs, and peptides. The workflow for SPA typically includes project consultation, feasibility evaluation, strategy definition, contract & payment, protein expression & purification, negative staining, sample freezing & data collection, 2D particle picking, 3D reconstruction, model refinement, and data delivery. Shuimu offers complimentary project feasibility assessment and regular meetings to track progress as part of their product advantages for SPA. Choosing Shuimu BioSciences for cryo-EM SPA is supported by their cutting-edge equipment, elite scientist team, extensive experience (over 200 cryo-EM projects, more than 150 structures resolved), uncompromising pursuit of resolution (best resolution of 1.8 Å, minimum molecular weight of 51 kDa resolved), and an AI-Driven Platform utilizing the independently developed SMART software suite to streamline data analysis.
2. Instrument Access (24 hours) Access to high-performance cryo-EM instruments is critical for structural determination. Shuimu BioSciences provides 24-hour instrument time for 300 kV data acquisition. They operate multiple instruments in both Beijing and Hangzhou. The source indicates they have eight 300 kV instruments in Beijing and six in Hangzhou available for 24-hour data collection services. The Cryo-EM Center is equipped with a state-of-the-art 300 kV cryo-EM and full supporting apparatus. This service caters to global academic and industry clients, offering convenient and efficient microscope-time reservation and data-collection services with a commitment to quality. Daily platform maintenance and professional quality service, including support for online remote hole selection and experienced technician support during data collection, ensure the equipment is always in optimal condition. Sample submission requirements for instrument access include delivering cryo-samples at least 1 working day in advance, guidelines for grid transport, and preparation details for samples prepared by the Shuimu platform.
3. Cryo Characterization Cryo-characterization utilizes ultra-low temperature technology to maintain samples in their natural state for high-resolution structural observation and analysis. This technique is particularly advantageous for observing the structure of proteins, liposomes, exosomes, and material interfaces. Shuimu BioSciences offers efficient and precise characterization services, focusing on LNPs, liposomes, AAV, and other viral vectors. A key tool for this service is NanoSMART, Shuimu's self-developed AI cryo-EM system. NanoSMART can automatically identify nanoparticle features from electron microscope images and generate detailed reports with one-click operation. The system can enhance the clarity of low-quality images to optimize recognition results. Cryo-characterization can provide detailed information such as size distribution, roundness, layered full/empty integrity. The NanoSMART system includes powerful data analysis functions and user-friendly data presentation features, providing overall project data summaries and detailed information displays of individual images. Case studies highlight NanoSMART's excellent performance in identifying liposomes and ultra-small targets like VLPs, even under varying image conditions. Sample submission requirements vary by sample type, with specific suggestions for liposomes, viruses (e.g., AAV), micelles, and LNPs.
4. Negative Staining & 2D Negative Staining Negative staining is an electron microscopy technique where the background is stained with dye instead of the target structure, allowing clear visualization of sample structure and morphology. This method is commonly used to observe viruses, nanoparticles, organelles, and protein complexes. Negative Staining & 2D Negative Staining are used for observing plant and animal tissue sections, such as cardiac slices, and for assessing particle homogeneity in proteins like AAV, exosomes, membrane proteins, viruses, and soluble proteins. Negative staining electron microscopy can quickly provide initial results at a lower cost, including sample particle size, uniformity, oligomeric state, morphology, particle density, protein structure, flexibility, sample integrity, conformation, and compositional heterogeneity. Negative Staining 2D specifically refers to analyzing structures using two-dimensional images, often for characterizing structures arranged on a 2D plane. The resolution obtainable typically ranges from 2-5 nanometers, suitable for observing molecular-level structures. Factors affecting results include particle aggregation and the presence of substances like polysaccharides, DMSO, and glycerol. Sample submission requirements include high protein purity (>95%), uniformity assessed by molecular sieve (>90% single peak), specific volume and concentration ranges (e.g., 50-100ul at 0.01-0.02 mg/ml), and buffer composition restrictions (e.g., salt ion concentration below 300 mM). Sending buffer for concentration exploration is also recommended.
5. MicroED Solutions Micro-electron diffraction (MicroED) is a cutting-edge technology for resolving high-resolution structures from microcrystals and nanocrystals, particularly suitable for organic compounds, small molecule drugs, peptides, and protein crystals. Shuimu BioSciences provides accurate structural insights using MicroED technology. Shuimu offers free evaluation services, covering feasibility analysis and risk warnings, leveraging their experience in electron microscopy and protein structure analysis. A key product advantage is Shuimu Technology's proprietary eTasED software, which integrates MicroED technology into conventional cryo-EM systems without additional modifications, significantly enhancing research efficiency and accuracy. Their elite team of PhD scientists is proficient in both cryo-EM and MicroED. They have successfully delivered over 80% of MicroED projects, achieving resolutions of 0.6~1.0Å. Case studies demonstrate that e-TasED can resolve structures of small molecules, peptides, and proteins, including examples like Proteinase K (protein, 29.05 kDa, 1.5 Å), FUS LC (peptide, 0.66 kDa, 0.65 Å), and Acetaminophen (small molecule, 0.151 kDa, 0.65 Å). Sample submission requires stable crystals of the small molecule, peptide, or protein, in powder or lump form, with a minimum amount visible to the naked eye (preferably ≥5mg).
Addressing Challenges with Cryo-EM
Traditional support grids used in cryo-EM sample preparation can face issues such as gas-liquid interface absorption, severe preferred orientation, high sample concentration thresholds (>1μM), significant background noise, and difficulty reconstructing small macromolecular structures. To overcome these bottlenecks, Shuimu has developed a series of graphene support grids called GraFuture™. GraFuture™ provides a potential solution to the preferred orientation problem and is suitable for applications involving small protein molecular weight, low concentration, strong background noise, and gas-liquid interface damage. GraFuture™ is available in Graphene Oxide (GO) and Reduced Graphene Oxide (RGO) versions.
Applications of Cryo-EM Services
The applications of cryo-EM are broad and impactful across life sciences and drug development.
1. Analyzing Biomacromolecules: SPA can reveal high-resolution 3D structures of various biomacromolecules, including membrane proteins (GPCRs like GPR75, ion channels like TRPV4, transporters), enzymes (like CYP51, PolQ), Ribosomes, DNA and RNA structures, protein–nucleic acid complexes (transcription complexes, viral capsid protein–RNA complexes), and viral particles (SARS-CoV-2, Influenza virus, African swine fever virus, human herpesvirus 6B, rabies virus glycoprotein).
2. Vaccine Field: Cryo-EM technology significantly increases efficiency and accuracy in vaccine research and development, quality control, and optimization.
o Viral Structure Analysis: Cryo-EM resolves 3D virus structures at near-atomic resolution, providing insights into viral entry mechanisms crucial for vaccine design. Examples include studies on SARS-CoV-2 spike protein structure with ACE2 for COVID-19 vaccine design, influenza virus studies for attenuated live vaccines, and measles virus studies on antibody neutralization mechanisms.
o Vaccine Quality Control: Cryo-EM is used to examine vaccine quality attributes like morphology, particle size, integrity, and aggregation throughout manufacturing stages, helping optimize processes and ensure product quality. It allows direct visualization of particle shape and integrity and accurate measurement of aggregation levels.
o Antibody–Vaccine Interaction Studies: Cryo-EM clarifies antibody binding to vaccine antigens, aiding optimization of vaccine immunogenicity. Examples include resolving structures of vaccine-induced antibodies with HIV-1 Env protein for broadly neutralizing antibody design and examining antibody binding to influenza virus surface proteins.
o Responding to Viral Mutations: Cryo-EM enables rapid structural analysis of new viral variants, supporting quick adjustments in vaccine designs, as seen with SARS-CoV-2 variants during the pandemic.
3. Antibody Drug Development: Cryo-EM plays a crucial role in antibody drug development.
o Antibody–Antigen Complex Structural Analysis: It reveals high-resolution 3D structures of these interactions, helping understand recognition mechanisms and binding sites, which is key for designing more effective antibody drugs.
o Mechanism of Action Studies: Cryo-EM is used to study how antibody drugs bind to targets and modulate signaling pathways, aiding the development of therapies targeting viral mutations, such as studies on antibodies against the Omicron variant of SARS-CoV-2.
o Optimization and Design: By analyzing existing antibody drug structures, cryo-EM helps identify potential improvements, revealing dynamic processes during binding and supporting the design of antibodies with higher affinity and specificity. It also assists in mapping conformational epitopes.
o Structural Analysis of Membrane Proteins and Complex Targets: Many antibody drug targets are membrane proteins like GPCRs. Cryo-EM resolves their high-resolution structures, shedding light on ligand binding, receptor activation, and signal transduction, crucial for developing antibodies against these targets.
o Accelerating Drug Development: The high resolution and rapid data acquisition capabilities of cryo-EM accelerate the optimization of antibody designs and overall drug development processes.
For detailed insights into how cryo-EM can advance your specific project, contact Shuimu BioSciences today at https://shuimubio.com/.
Why Choose Shuimu BioSciences for Cryo-EM Services?
Shuimu BioSciences highlights several core strengths and advantages in providing cryo-EM services. They claim to operate the world’s largest commercial cryo-EM platform, with multiple 300 kV instruments in Beijing and Hangzhou. They have completed over 400 cryo-EM projects and resolved more than 150 structures, achieving a best resolution of 1.8 Å. Their pursuit of resolution is uncompromising, resolving structures down to a minimum molecular weight of 51 kDa. Their team comprises PhD-level experts from preeminent institutions specializing in structural biology, protein science, and computational biology. Shuimu leverages proprietary AI algorithms and graphene-based grids (GraFuture) to significantly enhance the efficiency and accuracy of structure determination and data analysis. Their SMART software suite utilizes AI to streamline cryo-EM data analysis. NanoSMART is their self-developed AI system for cryo-characterization of nanoparticles. They have established efficient, advanced workflows and a dedicated team of EM engineers overseeing operations and maintenance. Their facilities maintain high annual available machine time and fault-free operation rates. Furthermore, Shuimu has built a complete protein expression and purification platform to minimize variability from sample transport and standardize the entire pipeline, successfully addressing challenges posed by difficult-to-express proteins. This enhancement of upstream capabilities allows them to provide “One-Stop” solutions from gene sequences to high-resolution 3D structures. They offer expertise in producing membrane proteins, including GPCRs, ion channels, and transport proteins.
Their extensive project experience includes resolving atomic-level resolution structures covering ion channels, GPCRs, antigen-antibody complexes, and spliceosomes. Specific examples of structures resolved by their platform have been published in top international journals.
Sample Submission Requirements
Specific sample submission requirements are provided for different services to ensure optimal results. General requirements often include:
· Protein samples: High purity (often >90% or >95%), specific concentration and volume requirements depending on the service (e.g., ≥ 2mg/mL and ≥ 100ul for SPA protein solution; 0.01-0.02 mg/ml for negative staining; 0.1-10μM for BLI; >10mg/ml for crystallography), minimizing freeze-thaw cycles.
· Buffer conditions: Restrictions on components like glycerol, DMSO, detergents, and salt concentration (e.g., ≤300mM salt ion concentration).
· Small molecules: Purity (>95%), sufficient amount (e.g., >10mg for SPA, >0.5mg for co-crystallization), solubility requirements (e.g., >100mM in DMSO or water), and often affinity data with target protein. For MicroED, stable crystals are required.
· Shipping: Samples should be freshly prepared or shipped frozen with dry ice. Advance notification is required for sample delivery.
· Instrument Access specific: Delivering cryo-samples 1 working day in advance, guidelines for grids and clips, and providing sample preparation conditions. Prepare a hard drive for data copying (reference size 4T/day).
Beyond Structure: Protein Preparation and Analysis Services
In addition to cryo-EM services, Shuimu BioSciences offers comprehensive protein preparation and analysis services. This integrated platform is crucial for successful structural determination projects, especially for difficult-to-express proteins. Services include:
· Protein Expression Systems: Utilizing E. coli, mammalian cells, insect cells, and cell-free expression systems. Each system has specific advantages and disadvantages depending on the protein type.
· Purification Processes: Employing techniques like affinity chromatography, ion-exchange chromatography, gel filtration (size-exclusion chromatography), and reverse-phase HPLC (RP-HPLC).
· Antibody Discovery: Including antibody screening for specificity, therapeutic R&D, drug discovery, target validation, and compound library screening. This service involves material preparation, antibody generation via phage libraries, panning, screening, production, purification, and validation using methods like ELISA, FACS, and Biacore (SPR).
· Protein Quality Control: Using methods like SDS-PAGE, Western blot, mass spectrometry, and thermal stability and solubility testing.
· Protein Assays: Providing services like SPR (Surface Plasmon Resonance), BLI (Bio-Layer Interferometry), and ELISA (Enzyme-Linked Immunosorbent Assay). These assays are vital for analyzing molecular interactions, binding kinetics, concentration, and affinity.
· Off-the-Shelf Protein List: Offering a list of high-quality proteins, including many important drug targets like GPCRs, ion channels, transporters, and kinases, as well as customized protein target services.
Shuimu also offers One-Stop Crystallographic Analysis services for targets like KRAS and SARS-CoV-2 M protein. This service covers the entire process from protein expression and purification to crystallization, data collection (using X-ray crystallography), and structure analysis. They emphasize their project experience and high cost-effectiveness for this service.
Conclusion
Cryo-EM technology is transforming structural biology, providing unprecedented insights into complex biological systems. Shuimu BioSciences stands out as a leading provider of comprehensive cryo-EM services, offering everything from sample preparation and characterization to high-resolution structure determination using SPA and MicroED. Their combination of cutting-edge equipment, AI-driven platforms, an elite scientific team, and extensive project experience makes them a powerful partner for researchers in academic and industrial settings. By integrating cryo-EM with robust protein services, Shuimu provides "One-Stop" solutions aimed at accelerating the discovery and development of vaccines, antibody drugs, and other critical biomolecules.
To explore how Shuimu BioSciences' cryo-EM services can accelerate your research projects and contribute to breakthroughs in structural biology, visit https://shuimubio.com/ for more information and to discuss your specific needs.