Peptide Sequencing Service by Mass Spectrometry

Peptides are biological macromolecules composed of two or more amino acids linked by peptide bonds, exhibiting diverse biological functions. Tandem mass spectrometry (MS/MS) peptide sequencing identifies the amino acid composition and sequence of proteins or peptides using MS/MS. In the initial MS stage, peptide fragments are ionized and analyzed based on their mass-to-charge ratio (m/z), resulting in a MS1 that reflects the m/z and relative abundance of the peptide fragments. Subsequent fragmentation of these peptide fragments, followed by another m/z analysis, generates a MS2 detailing the m/z and relative abundance of the fragment ions. Common methods of MS/MS include ESI-MS/MS, MALDI-MS/MS, and LC-MS/MS.

Analysis Workflow

1. Protein Extraction

Isolate proteins from the sample.

2. Enzymatic Digestion

Use specific proteases to cleave proteins into peptide fragments.

3. Separation and Purification

Employ LC to separate and purify the resulting peptide fragments.

4. Ionization

Convert peptide samples into gas-phase ions.

5. MS1 Analysis

Analyze gas-phase ion masses to obtain peptide m/z information.

6. Ion Fragmentation

Fragment specific peptide ions to generate fragment ions.

7. MS2 Analysis

Analyze the fragment ions' mass to obtain their m/z information.

8. Data Processing and Analysis

Compare MS2 data with known protein databases to infer the amino acid sequences of peptide fragments.

Technology Advantages

1. High Sensitivity

Detects peptides at levels as low as picomole (pmol) or even femtomole (fmol).

2. High Accuracy and High Resolution

Precisely measures the m/z of peptide fragments, accurately identifying peptides and ions with similar masses, and providing detailed peptide sequence information.

3. High Throughput

Capable of analyzing large sample volumes rapidly. When combined with LC, it can identify thousands of proteins in complex biological samples quickly.

4. High Coverage

Enhanced sequence coverage improves the accuracy of protein and peptide identification.

Deliverables

In the technical report, MtoZ Biolabs will provide you with detailed technical information, including: