Multiplexing Protein Quantification Core

Michael Kinter, Ph.D.

Michael Kinter, Ph.D.

Aging and Metabolism Research Program

Oklahoma Medical Research Foundation

mike-kinter@omrf.org

The Multiplexing Protein Quantification Core of the Oklahoma Nathan Shock Center uses LC-tandem MS with selected reaction monitoring (SRM) to measure protein abundance. SRM is unique among the various quantitative mass spectrometry methods because, like Western blots, proteins are carefully selected and targeted for quantification. Targeting is achieved by designing the SRM method to measure the abundance of several peptides, which are unique to the protein when digested with trypsin. These peptides can be detected in complex samples, such as whole tissue homogenates, based on their sequence-specific fragmentation reactions driven by collision-induced dissociation (CID). The peptides are identified as chromatographic peaks at characteristic retention times and the abundance calculated based on the integrated area of those peaks.

Two key features of SRM make this a powerful new tool for Geroscience research.  First, SRM is a high throughput method where one can measure ~30 proteins in a single assay. The Core has developed panels of protein assays that allow investigators to interrogate entire pathways such as antioxidant proteins, β-oxidation, glycolysis, TCA-cycle, and others with new assay panels continuously being developed.  Second, assays for proteins involved in any pathway can be designed and validated for proteins from any animal.  The Core will provide two services:

  • Quantification of proteins in various pathways for tissues/cells from laboratory rodents as well as other animal models. Currently, we have panels of proteins to the pathways shown below for mice/rats and Drosophila. Cost: $60/sample for the first panel of proteins, and $30 for each additional panel of proteins.
  • Develop panels of proteins to pathways for individual investigators.  These panels of proteins can be developed for almost any animal.   In additions to rats and mice, we are especially interested in developing panels of proteins for animals used in aging research, such as invertebrates (yeast, C. elegans, Drosophila) and exceptionally long-lived species (e.g., naked mole rats, bats, birds, etc.).  Once these panels of proteins have been developed for the investigator, they will be available to the research community. Cost: ~$1,000 to develop a panel of 20 proteins.

Panels of Proteins Currently Available for Mice/Rats: