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Oxygen-18 Labeling Kit for Protein Quantification using Mass Spectroscopy

Technology Benefits

Advantages: Provides extremely accurate measurements of proteins by minimizing procedural errors Suitable for membrane proteins, and more precise quantification than possible with 2-dimensional gels Can be used to develop a protein labeling kit as a simple and dependable comparative proteomics tool

Technology Application

protein quantification

Detailed Technology Description

The proteolytic 18O labeling method allows estimation of the relative abundance of individual proteins between two samples based on analysis of peptides. This technique utilizes a protease and water (H216O and H218O) to produce labeled peptides; peptides in one sample incorporates 16O by labeling in H216O, and the other sample incorporates 18O by labeling in H218O. The samples are mixed in a 1:1 ratio and analyzed using mass spec to identify and quantify the proteins from which the peptides originated. A kit based on this technology would provide scientists easy access to the mass spectrometry based quantitative proteomics technique. The suggested kit provides trypsin, 16O- and 18O-water, a buffer solution for tryptic digestion, and a reagent to inactivate trypsin.

Industry

Disease Diagnostic/Treatment

Sub Category

Cancer/Tumor

*Abstract

Common Artifacts Occuring in Comparative Proteomics:Proteolytic 18O labeling is a commonly used method for protein quantification. However, this technique often suffers from 1) incomplete 18O labeling due to inefficient labeling reaction conditions, and 2) the 18O to 16O back exchange reaction after the labeling reaction due to residual protease activity. As a result, peptides may be labeled with 0, 1, or 2 18O, when the goal is for all peptides to be labeled with two 18O. Our patented method leads to almost 100% labeling of peptides with 2 18O, enabling highly accurate proteomic analysis.

*Principal Investigator

Name: Masaru Miyagi

Department:

Country/Region

USA