Basic Principles of Protein Mass Spectrometry Identification
Proteins are biological macromolecules composed of one or more peptide chains arranged in a specific manner. Most proteins naturally fold into a specific three-dimensional structure. Protein identification mainly involves recognizing the primary structure of a protein, which includes determining the sequence of amino acids in the peptide chains, molecular weight, and the number and position of disulfide bonds. Protein identification is fundamental to proteomics and holds significant research value in biological studies.
Traditional methods for protein identification, such as protein micro-sequencing and amino acid composition analysis (e.g., Edman degradation), suffer from low throughput, time consumption, labor intensity, non-automation, and poor sensitivity. With the rise of mass spectrometry (MS) technology, using MS for high-throughput, high-sensitivity separation, identification, and analysis of proteins has gradually become mainstream.
Mass spectrometry identification is characterized by high sensitivity, high accuracy, and a high degree of automation. It can accurately determine the relative molecular mass, amino acid sequence, and post-translational modifications of peptides and proteins. Therefore, MS technology is widely used in quantitative and qualitative studies of proteins, especially in researching the pathogenesis of major diseases and pharmacological control mechanisms. A mass spectrometer generally consists of an ion source, a mass analyzer, and an ion detector.
Typically, tandem mass spectrometry (MS/MS) and liquid chromatography-mass spectrometry (LC-MS/MS) are used as methods for protein mass spectrometry identification. Simple protein samples use MS/MS, while complex mixed protein samples use LC-MS/MS. The principles of both methods are similar. The basic principle of MS/MS for protein identification involves digesting proteins with proteases into peptides, which are ionized in the mass spectrometer and carry a certain amount of charge. The ion detector can identify the mass-to-charge ratio of each peptide, thereby determining their relative molecular mass. The spectrometer will further fragment some peptides for secondary analysis, producing a secondary mass spectrum to obtain sequence information of the peptides. The protein can be identified through mass spectrometry database comparison and analysis. The difference is that LC-MS/MS includes an additional step of high-performance liquid chromatography separation compared to MS/MS.
Biotech company Baitai Parker uses the Orbitrap Fusion mass spectrometry platform. The Orbitrap Fusion Lumos mass spectrometry platform combined with Nano-LC can efficiently and accuratelyidentify proteins in various samplesand provide related proteomics services. You only need to send us your requirements and samples, and we will handle all subsequent project matters, including sample pretreatment, mass spectrometry analysis, raw mass spectrometry data analysis, and omics analysis.
Related services:
Mass spectrometry determination of protein molecular mass
Sequence analysis based on mass spectrometry
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