SILAC-based quantitative proteomics is an innovative service used in high throughput quantitative analysis of large protein complexes, chemical biology, biomarker discovery and protein-protein interactions. SILAC is used to quantify protein expression differences in up to 2 or 3 samples from cells. Cells are grown in identical conditions, with one cell line incorporating heavy isotopic amino acids (usually Arginine [U-13C6, 15N4] and Lys [U-13C6]) thereby taking advantage of the normal metabolic machinery of the cell to label the proteins. The light and heavy amino acids are chemically identical and thus co-elute in SDS PAGE and HPLC separation. But, since the peptides are isotopically distinct, the light and heavy labeled peptides are clearly distinguishable by mass spectrometry. A small percentage of the sample is removed early on to check incorporation of the heavy amino acids and a growth of 8-10 doubling times is recommended for a high incorporation. Samples should be mixed immediately after the cells are grown.
This approach provides an unbiased strategy that can reveal how specifically either inhibitors, or other perturbations, affect the dynamic properties and/or cellular distributions of proteins. It can also be used as a sensitive and effective method to determine the specific interaction partners of proteins under study.
1) Protein GO analysis
2) Protein KEGG analysis
3) Differentially expressed proteins GO enrichment analysis
4) Differentially expressed proteins KEGG enrichment analysis
5) Differentially expressed proteins cluster analysis
6) Differentially expressed proteins PPI analysis