Stable Isotope Labeling of Amino Acids & Derivatives

Isotopic labeling is a technique that tracks isotopes through reactions, metabolic pathways, or cellular pathways. Based on an experienced scientific team and advanced facilities, BOC Sciences is able to use stable isotopes (such as ²H, ¹³C, ¹⁵N and ¹⁸O) for labeling of amino acids & derivatives. Moreover, BOC Sciences focuses on quality assurance, and our stable isotope labeling services comply with the requirements of the quality management system to ensure the accuracy and reliability of labeling results.

Fig.1 SILAC with ¹³C₆-Arg. (Ong et al., 2003)

Stable Isotope Labeled Amino Acids

Stable isotope-labeled amino acids are a tool used to study protein metabolism and biochemical reactions. This labeling method takes advantage of the properties of stable isotopes and introduces them into amino acid molecules, so that the metabolic process of amino acids in organisms can be tracked. Stable isotope-labeled amino acids are usually labeled with stable isotopes of carbon, nitrogen, hydrogen and other elements. These isotopes have the same chemical properties but different masses than isotopes found in nature. Therefore, by measuring changes in isotope ratios, we can understand the metabolic process of amino acids in organisms. In addition, proteins, peptides and other small biological molecules can be labeled by chemical means to specific functional groups, such as stable amino acid labeling technology (SILAC), ¹⁵N/¹⁴N in cell culture and relative and absolute quantitative isotope labeling technology (iTRAQ).

Stable Isotope Labeling Services for Amino Acids & Derivatives

The isotope labeling services provided by BOC Sciences are customized, and can be optimized and adjusted according to the specific needs of customers. These needs include customized services for the selection of stable isotopes, the type of amino acids and their derivatives to be labeled, and the location of the label.

Stable Isotope Labeling by Amino Acids in Cell Culture (SILAC)

The SILAC method uses amino acids containing stable isotopes to replace the natural isotope amino acids in conventional culture media, so that the proteins synthesized by cells are labeled with stable isotope. This approach can be used in quantitative proteomic studies to reveal changes in protein quantification and metabolism by comparing the relative abundance of proteins in labeled and non-labeled samples. SILAC has become a very powerful method for studying cellular signal transduction, post-translational modification (such as phosphorylation), protein-protein interaction and gene expression regulation. In addition, SILAC has become an important method of secretology, a global research and secretion pathway of secreted proteins, and can be used to distinguish between proteins secreted by cultured cells and serum pollutants.

• ¹³C-Metabolic Flux Analysis

By culturing cells in media containing a C-labeled metabolic substrate such as glucose, the flow of C-labeled carbon through metabolic pathways can be tracked.

• ¹⁵N-Ammonium Assimilation Method

¹⁵N-Ammonium Assimilation method can introduce ¹⁵N-labeled nitrogen into the amino acids and proteins synthesized by the cells by culturing cells in a medium containing ¹⁵N-labeled ammonium salts.

Analysis Services for Stable Isotope Labeled Amino Acids

After purification, the labeled amino acids or their derivatives can be subjected to quantitative analysis, such as metabolic flux analysis, protein quantification, etc. Quantitative determination can use mass spectrometry, liquid chromatography and other technologies, combined with standard curves or internal standard substances for quantitative calculation and analysis.

Project Workflow

Reference

1. Ong S E, et al. Properties of 13C-substituted arginine in stable isotope labeling by amino acids in cell culture (SILAC)[J]. Journal of proteome research, 2003, 2(2): 173-181.