What Measurements Does Proteomics Include
Proteomics is the scientific discipline focused on the large-scale study of proteins, particularly their structures, functions, expression patterns, and interactions within cells, tissues, or entire organisms. The ultimate aim is to obtain a comprehensive understanding of these proteins. Proteomics involves various analytical and technological methodologies, as highlighted below.
Protein Extraction and Separation
The initial stage of proteomics research involves the extraction and separation of proteins. Common extraction techniques include ultrasonic disruption, freeze-thaw cycles, and chemical lysis. Post-extraction, proteins typically undergo separation for subsequent analysis. The primary separation techniques are:
1. Gel Electrophoresis
Including SDS-PAGE, which separates proteins based on molecular weight.
2. Isoelectric Focusing
This method separates proteins according to their isoelectric points.
3. Two-Dimensional Electrophoresis
Combining SDS-PAGE with isoelectric focusing offers high-resolution protein separation.
Protein Identification
A central component of proteomics is protein identification, frequently accomplished through mass spectrometry. Mass Spectrometry (MS) provides precise measurements of protein molecular weights and amino acid sequences. Common techniques include:
1. Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS)
Ideal for rapid and large-scale protein identification.
2. Electrospray Ionization Mass Spectrometry (ESI-MS)
Effective for analyzing complex protein mixtures.
3. Tandem Mass Spectrometry (MS/MS)
This technique elucidates protein sequences through fragmented ion analysis.
Protein Quantification
Evaluating protein expression level changes under varying conditions necessitates accurate quantification methods, including:
1. Label-Based Quantification
Such as Isotope-Coded Affinity Tag (ICAT) and Isobaric Tags for Relative and Absolute Quantitation (iTRAQ).
2. Label-Free Quantification
This method relies on the intensity of MS signals.
Analysis of Protein Modifications
Post-translational modifications, such as phosphorylation, acetylation, and glycosylation, critically influence protein function and activity. Analytical techniques include:
1. Phosphorylation Analysis
Utilizes phosphorylation-specific antibodies combined with MS.
2. Acetylation Analysis
Incorporates immunoprecipitation followed by MS.
Study of Protein Interactions
Understanding protein interactions is vital for elucidating functions within biological networks. Key methodologies include:
1. Yeast Two-Hybrid System
Effective for detecting direct protein-protein interactions.
2. Co-Immunoprecipitation (Co-IP)
Used to validate protein interactions in vivo.
3. Affinity Purification-Mass Spectrometry (AP-MS)
This technique identifies the components of protein complexes.
MtoZ Biolabs, an integrated chromatography and mass spectrometry (MS) services provider.
Related Services
How to order?
