Oxygen-18 Labeling Kit for
Protein Quantification using Mass Spectrometry
The University of North Dakota has developed a method for comparative proteomics that maximizes precision
and reproducibility of protein quantification using proteolytic oxygen-18 labeling.
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.
Our Technology:
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.
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
Reference#: UND05-07
US Pat. 7,476,546
US Pat. 8,669,117
US Pat. 8,580,534
For more information, contact:
Michael F. Moore, CLP
Office of Intellectual Property Commercialization & Economic Development
University of North Dakota
(701) 777-6709/ [email protected]