Intact Mass Spectrometry
Intact mass spectrometry (IMS) is a cutting-edge analytical technique for directly determining the molecular weight of biomolecules such as proteins, antibodies, and viral vectors. By bypassing enzymatic digestion or chemical modification, IMS provides comprehensive mass information while preserving the integrity of the molecule. With its exceptional sensitivity, resolution, and throughput, IMS has become a critical tool in proteomics, drug development, and biomarker discovery.
Principles of Intact Mass Spectrometry
IMS operates on the principles of high-resolution mass spectrometry, using ionization to convert intact molecules into charged particles for analysis of their mass-to-charge ratio (m/z). Common ionization methods include electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI). ESI excels at generating multiply charged ions from large proteins and peptides, preserving their native structures, whereas MALDI offers rapid analysis of complex mixtures, particularly for proteomic applications.
High-resolution mass spectrometers, such as Orbitrap and Fourier-transform ion cyclotron resonance (FTICR) instruments, are essential for IMS. These advanced platforms provide precise molecular mass data and can detect subtle differences arising from post-translational modifications (PTMs) or isotopic variations.
Advantages of Intact Mass Spectrometry
IMS offers distinct benefits compared to traditional peptide-based approaches:
1. Simplified Sample Preparation
Eliminates the need for enzymatic digestion or chemical modification, reducing complexity and error.
2. Accurate Mass Determination
Directly measures intact molecular weight, enabling analysis of structurally complex biomolecules.
3. High Sensitivity and Throughput
Rapidly detects low-abundance species, making it ideal for complex sample analysis.
4. Comprehensive PTM Analysis
Accurately identifies mass shifts associated with glycosylation, phosphorylation, and other modifications.
Applications of Intact Mass Spectrometry
1. Protein Characterization
IMS is instrumental in analyzing molecular mass and modifications of proteins, including monoclonal antibodies (mAbs). It reveals the mass of light and heavy chains, along with modification patterns.
2. Drug Development
MS provides critical data on drug molecule integrity, aggregation, and modifications, supporting quality control and development.
3. Post-Translational Modifications
IMS detects subtle mass variations due to PTMs, offering insights into regulatory mechanisms of protein function.
4. Multimer and Complex Analysis
IMS characterizes non-covalent protein assemblies, elucidating protein interactions and structural organization.
Challenges and Solutions
Despite its advantages, IMS presents challenges:
1. Ionization of Large Molecules
High molecular weight proteins may ionize inefficiently, requiring optimized ionization conditions.
2. Complex Sample Interference
Background signals can obscure target molecule measurements.
3. Resolution Demands
Subtle mass differences necessitate advanced high-resolution instruments.
These challenges are addressed through sample purification, optimized ionization, and coupling IMS with liquid chromatography. Additionally, advanced instruments improve sensitivity and resolution, expanding IMS capabilities for complex samples.
With state-of-the-art platforms such as Thermo Fisher’s Orbitrap Fusion Lumos and Q Exactive HF, MtoZ Biolabs provides precise and reliable IMS services. Our expertise spans PTM analysis, protein complex characterization, and biopharmaceutical profiling. Recognized for rapid, customized solutions, MtoZ Biolabs supports both research and industrial applications, delivering insights that advance scientific discovery.
MtoZ Biolabs, an integrated chromatography and mass spectrometry (MS) services provider.
Related Services
How to order?
