Cryo-electron microscopy (cryo-EM) has revolutionized structural biology and drug discovery by enabling the determination of high-resolution structures of complex biological molecules that are difficult to crystallize. As the demand for structural information grows, access to advanced cryo-EM technology and expertise becomes increasingly critical. This is where specialized providers offering comprehensive cryo-EM services and cryo-EM outsourcing become invaluable. By partnering with a leading platform, researchers and companies can accelerate their projects, access cutting-edge technology, and gain deep structural insights without the significant investment required for in-house facilities and expertise.

Shuimu Bio, founded in 2017 at Tsinghua University, is Asia's first commercial platform providing cryo-EM structure analysis services. With a core team comprising experts in life sciences, computational science, IT, and the pharmaceutical industry, Shuimu Bio has established itself as a global leader in commercial cryo-EM. The company offers a one-stop solution from gene sequence to high-precision 3D protein structure, integrating protein expression, purification, and characterization with advanced cryo-EM services.

Comprehensive Cryo-EM Services Offered

Shuimu Bio provides a wide range of cryo-EM services designed to meet diverse research needs, from initial sample characterization to high-resolution structure determination.

1. "One-Stop" Single Particle Analysis (SPA) Solution Single Particle Analysis is a powerful cryo-EM technique used to determine the high-resolution three-dimensional structures of biological macromolecules such as proteins and viruses. It involves capturing numerous 2D images of purified particles and using computational algorithms to process and reconstruct a 3D structure model.

o Advantages of Cryo-EM SPA:

§ Maintains the sample in a near-native state.

§ Can capture multiple conformational states.

§ Requires only small amounts of sample.

§ Effective for determining the structure of heterogeneous protein complexes.

o Applications of SPA: SPA can reveal the high-resolution 3D structure of various biological macromolecules including:

§ Proteins: Membrane proteins (GPCRs, ion channels, transporters), enzymes, and ribosomes. Shuimu Bio has experience with specific GPCRs like GPR75, CsgG, TRPML1, and enzymes like CYP51 and PolQ.

§ DNA and RNA Structures: Including the DNA double helix and its interactions, as well as viral RNA and ribosomal RNA.

§ Protein-Nucleic Acid Complexes: Such as transcription complexes (RNA polymerase with DNA templates) and viral capsid protein-RNA complexes.

§ Virus Particles: Including SARS-CoV-2 (S protein complex with ACE2), influenza virus (surface spike protein), African Swine Fever virus, Human Herpesvirus 6B, and Rabies virus glycoprotein.

o Addressing Challenges: Shuimu Bio utilizes technologies like GraFuture™, GO, and RGO to improve results for challenging protein samples with issues such as small molecular weight, low concentration, high background noise, air-liquid interface damage, and preferred orientation.

2. MicroED Solution Micro-electron diffraction (MicroED) is an advanced technique for precisely resolving high-resolution structures from microcrystals and nanocrystals, particularly useful for organic compounds. Shuimu Bio offers MicroED solutions for small molecule drugs, peptides, and protein crystals, providing accurate structural insights.

o Capabilities: High-resolution structure determination for challenging small molecules, peptides, and macromolecules.

o Proprietary Technology: Watermark technology includes the original eTasED software, which seamlessly integrates microED technology into conventional cryo-EM systems without hardware modifications, enhancing efficiency and accuracy.

o Track Record: Shuimu Bio reports successfully delivering over 80% of MicroED projects with resolutions reaching 0.6-1.0 Å. Examples include Proteinase K (1.50 Å), FUS LC RAC1 (0.65 Å), and Acetaminophen (0.65 Å).

3. Machine Time Service (24h) For researchers and companies with prepared cryo-EM grids, Shuimu Bio offers 24/7 machine time for data collection.

o Platform Scale: Shuimu Bio operates cryo-EM platforms in Beijing (2 units) and Hangzhou (6 units), equipped with 300kV high-end cryo-EM microscopes. The platform currently has 8 electron microscopes and full auxiliary equipment.

o Service Features: 24/7 availability with urgent appointment channels. Full-process closed-loop management, including auxiliary equipment like Vitrobot and surface plasma processors.

o AI Integration: Utilizes proprietary SMART software to reduce machine runtime, data volume, and improve analysis efficiency.

o Expert Support: Provides online remote hole selection and expert selection guided by Shuimu scientists. Experienced technical personnel ensure professional operation and real-time response to issues during data collection.

o Platform Maintenance: Emphasizes daily maintenance to ensure equipment is in optimal condition, offering stable and reliable service. Microscopes have an annual availability of over 330 days, with a fault-free operation rate exceeding 97%.

4. Negative Staining & Negative Staining 2D Negative staining is an electron microscopy technique that stains the background rather than the sample itself, providing clear visualization of the sample's structure and morphology. Shuimu Bio offers this service for rapid acquisition of low-resolution 2D projection images of macromolecular complexes, serving as a basis for further cryo-EM studies.

o Purpose: Useful for initial sample characterization at a lower cost.

o Information Provided: Preliminary data on particle size, uniformity, oligomeric state, morphology, particle density/sample concentration, protein structure, flexibility, sample integrity, and conformational and compositional heterogeneity.

o Resolution: Transmittance electron microscopy can provide resolutions up to 2-5 nanometers for observing molecular structures using this technique.

5. Cryo-Characterization Cryo-characterization uses cryo-EM to maintain samples in their natural state for high-resolution structural observation and analysis. This service is particularly advantageous for observing the structure of proteins, liposomes, exosome, and material interfaces. Shuimu Bio specializes in researching LNPs, liposomes, AAV, and other viral vectors.

o AI-Powered Analysis: The NanoSMART system, developed in-house, is an AI-driven cryo-EM system that automatically identifies nanoparticle features from images. It provides detailed reports with one-click operation and enhances low-quality images for better recognition.

o Analyzed Features: Includes size distribution, circularity, layering, fill/empty status, and integrity.

o Statistical Insights: Provides comprehensive statistical analysis, including histograms for size, circularity, and bilayer membrane, multidimensional statistics, and detailed table displays. Users can view overall project data summaries and detailed information for individual images.

o Case Studies: Demonstrated effectiveness in identifying liposome types and VLP types, showcasing high accuracy even with challenging images.

Enabling Cryo-EM Outsourcing with Integrated Services

The value of cryo-EM outsourcing is significantly enhanced when bundled with integrated services that address the entire workflow. Shuimu Bio's one-stop solution aims to provide services from sample preparation to final structure resolution.

1. Protein Preparation and Analysis Services Obtaining high-quality protein samples is crucial for successful cryo-EM. Shuimu Bio's protein platform focuses on preparing target proteins using various expression systems.

o Protein Expression Systems:

§ E. coli expression system: Economical, fast, high yield, suitable for prokaryotic and simple eukaryotic proteins.

§ Mammalian cell expression system: Preferred for therapeutic proteins, vaccines, and antibodies, providing near-native state, folding, and post-translational modifications.

§ Insect cell expression system: Uses baculovirus vector, high expression efficiency, large foreign gene capacity, performs post-translational modifications.

§ Cell-free expression system: In vitro synthesis from DNA or mRNA template, significantly reduces expression time from days to hours, faster and more efficient.

o Protein Purification Methods: Includes affinity chromatography, ion exchange chromatography, gel filtration chromatography, and reverse-phase high-performance liquid chromatography (RP-HPLC).

o Protein Characterization: Techniques like SDS-PAGE, BN-PAGE, HPLC for purity and uniformity, and mass spectrometry for verification and modifications.

o Protein-Protein or Protein-Molecule Binding Analysis: Using techniques such as SPR, BLI, MST, ITC.

o Protein Assay Services: Shuimu Bio provides SPR (Surface Plasmon Resonance), BLI (Biolayer Interferometry), and ELISA (Enzyme-Linked Immunosorbent Assay) services for binding kinetics and protein quantification. These assays are critical for validating sample quality and interactions before moving to cryo-EM.

o Shelf Protein List: Shuimu Bio maintains a list of high-quality proteins, including many membrane proteins like GPR75, PolQ, OX-2, and others, available as research tools.

2. "One-Stop" Crystal Structure Analysis While cryo-EM excels with flexible or large complexes, X-ray crystallography remains vital for crystallizable targets. Shuimu Bio offers one-stop crystal structure analysis for targets like antigen-antibody complexes, small molecule drugs, and peptides. This service covers the entire workflow from protein expression and purification to crystal growth, data collection, and structure resolution. Shuimu Bio has successfully completed over 200 such projects.

3. Antibody Discovery Related to drug discovery services, Shuimu Bio provides antibody discovery services, including antigen preparation, antibody generation from libraries (llama natural, synthetic phage), panning and screening, production, purification, and validation. Validation includes binding activity via ELISA and affinity testing using Biacore (SPR).

Applications of Cryo-EM in Key Therapeutic Areas

Cryo-EM, delivered through comprehensive cryo-EM services and cryo-EM outsourcing, has significant applications across various fields, particularly in drug and vaccine development.

1. Vaccine Field Cryo-EM is a powerful tool in vaccine research and development.

o Virus Structure Analysis: Provides near-atomic resolution of viral structures, aiding understanding of invasion mechanisms and vaccine design. Examples include SARS-CoV-2 (Spike protein-ACE2 structure), influenza virus (novel strategies for live attenuated vaccines), and measles virus (how neutralizing antibodies block infection).

o Vaccine Quality Control: Used to assess morphology, particle size, integrity, and aggregation of vaccine particles at different production stages, optimizing processes and ensuring quality.

o Antibody-Vaccine Interaction Studies: Helps understand the binding mechanism of antibodies to vaccine antigens to optimize immunogenicity. Examples include HIV (vaccine-induced antibody complex with HIV-1 Env protein) and influenza virus (antibody binding to surface proteins).

o Responding to Viral Variation: Rapidly resolving structures of new virus variants allows scientists to adapt vaccine design strategies promptly, as demonstrated during the COVID-19 pandemic.

2. Antibody Drug Field Cryo-EM has significant value in antibody drug discovery.

o Antibody-Antigen Complex Structure Analysis: Resolving high-resolution structures of antibody-antigen complexes helps understand recognition mechanisms and binding sites. This structural information is critical for designing more effective antibody drugs.

o Mechanism of Action Studies: Used to investigate how antibody drugs interact with targets, including binding, activation, or inhibition of signaling pathways. For example, resolving structures of broad-spectrum neutralizing antibodies against SARS-CoV-2 variants has revealed molecular bases for their activity.

o Antibody Drug Optimization and Design: Structural analysis can reveal potential optimization points, such as dynamic processes and conformational changes during binding, aiding the design of antibodies with higher affinity and specificity. It can also help analyze conformational epitopes.

o Membrane Protein and Complex Target Analysis: Cryo-EM can resolve high-resolution structures of membrane proteins like GPCRs, which are common antibody targets, revealing mechanisms of ligand binding, receptor activation, and signaling.

o Accelerating Drug Development: High resolution and fast data acquisition enable more efficient structural analysis, accelerating the antibody drug R&D process.

3. Small Molecule Drug Field Cryo-EM is also important in small molecule drug discovery.

o Target Structure Analysis: Resolves high-resolution structures of biological macromolecules like membrane proteins and enzymes, helping understand target sites for small molecule drugs. For instance, analyzing GPCR structures bound to small molecule ligands provides a structural basis for designing highly selective and effective drugs.

o Mechanism of Action Studies: Used to study the interaction mechanisms between small molecule drugs and their targets. Resolving complex structures reveals how drugs activate or inhibit receptors and regulate signaling pathways, crucial for optimizing drug design and efficacy.

o Fragment-Based Drug Discovery (FBDD): Shows potential in FBDD by revealing details of interactions between small molecule fragments and protein targets, aiding screening and optimization of drug candidates.

o Accelerating Drug Development: Similar to antibody drugs, the efficiency of cryo-EM accelerates the small molecule drug R&D process by quickly providing detailed structural information.

o Biased Ligand Studies: Particularly advantageous for studying biased ligands that selectively activate or inhibit specific downstream signaling pathways mediated by GPCRs, offering insights for developing novel small molecule drugs.

o Complex Target Structure Analysis: Can resolve structures of complex targets like membrane proteins and enzyme complexes, which are valuable in small molecule drug development.

Why Choose Shuimu Bio for Cryo-EM Services and Outsourcing?

Choosing the right partner for cryo-EM outsourcing is critical for research success. Shuimu Bio offers distinct advantages:

· Global Scale and Facilities: Operates the world's largest commercial cryo-EM platform, equipped with high-end 300kV microscopes and auxiliary equipment. The facilities are designed for high-quality structure determination, featuring top-tier microscopes and advanced computing platforms.

· Extensive Experience: Possesses experience with over 400 cryo-EM projects and microcrystal electron diffraction structures, successfully analyzing over 150 protein structures. Experience covers diverse samples from membrane proteins to antigen-antibody complexes.

· Commitment to High Resolution: Dedicated to achieving excellent resolution, having resolved over 150 protein structures with a best resolution of 1.8 Å, and reaching a breakthrough 1.4 Å resolution. They can also handle structures as small as 51 kDa.

· AI-Driven Platform: Independent research and development of AI algorithms and software like SMART, NanoSMART, and eTasED significantly enhance data analysis efficiency and accuracy across different cryo-EM workflows.

· Proprietary Consumables: Developed GraFuture™ graphene grid support membranes, which improve results for challenging samples.

· Expert Team: Core team consists of accomplished scientists with doctoral degrees from leading institutions, specializing in structural biology, protein science, and computational biology. Experienced technical engineers ensure daily operation and maintenance of facilities.

· One-Stop Solution: The integrated protein expression and purification platform, combined with cryo-EM services, provides a seamless workflow from gene sequence to high-precision structure, reducing experimental variability from sample transport.

· Quality Control: Stringent quality control measures, including comprehensive cryo-EM analysis and characterization, ensure samples meet research requirements.

· Client Support: Offers free project evaluation, competitive pricing, fast delivery, and regular meetings to track project progress. A global customer service center collects user feedback and technical needs.

Track Record and Network

Shuimu Bio's expertise and platform have contributed to numerous research outcomes published in top international journals. These publications cover a wide range of biological targets, including ion channels, GPCRs, antigen-antibody complexes, and spliceosomes. The company's "Watermark Circle of Friends" or network includes various partners, reflecting its collaborative ecosystem.

Conclusion

Accessing advanced cryo-EM services through cryo-EM outsourcing is a strategic decision for researchers and organizations aiming to obtain high-resolution structural insights efficiently. Shuimu Bio provides a robust, comprehensive platform covering the entire structural biology pipeline, from protein preparation to advanced cryo-EM techniques like SPA, MicroED, and specialized characterization for nanoparticles. Their scale, experience, cutting-edge technology, AI integration, and expert team make them a leading partner in accelerating drug discovery, vaccine development, and fundamental life science research. By offering a true one-stop solution with a focus on quality and high resolution, Shuimu Bio empowers clients to overcome technical hurdles and achieve their research goals.

For more information on how Shuimu Bio's cryo-EM services and cryo-EM outsourcing solutions can benefit your research, please visit https://shuimubio.com/.