MRM-MS for Protein Quantification and Quantitation
Blog Oct 22, 2013
Agilent and MRM Proteomics recently announced the launch of MRM Proteomics' PeptiQuant MRM Assay Kits for quality control in quantitative plasma proteomic analyses based on multiple-reaction monitoring.
We caught up with Andrew Munk, CEO of MRM Proteomics, to understand more about this product release and the partnership with Agilent.
AB: Can you tell me about MRM Proteomics?
Andrew Munk (AM): MRM Proteomics provides advanced quantitative proteomic services and kits to the pharmaceutical, biotechnology and diagnostics industries. The company’s core expertise is in the use of innovative mass spectrometry based technology platforms for protein biomarker discovery/ validation and clinical diagnostics development.
We specialize in highly multiplexed quantitation of proteins (100+) in complex biological samples such as blood, cerebrospinal fluid (CSF), urine and other fluids/lysates through the use of Multiple Reaction Monitoring-Mass Spectrometry (MRM-MS) assays.
We have developed quantitative MRM-MS assays for 100s of human proteins (all with internal standards). ELISAs are not available for a large number of these proteins. Our MRM assays (existing and customized) have several significant advantages over other protein/biomarker quantification methods including short assay development time (6 to 12 weeks), no antibody development required and absolute molecular specificity.
What differentiates us as a company is that MRM Proteomics’ workflows utilize minimal sample volumes (20 ul) and are capable of unparalleled specificity and sensitivity, without the need for depletion of high-abundance proteins. Furthermore, we use stable isotope-labeled (SIS) peptides as internal standards in all our protein quantitation assays which is not the case for most companies using MRM-MS. Using this approach we can achieve ng-pg/ml levels of sensitivity and screen for chemical interferences which can’t be done without using internal standards.
AB: How did the collaboration with Agilent come about?
AM: Agilent and our CSO, Christoph Borchers, have a long term working relationship around quantitative proteomics. When MRM Proteomics was established it was a natural evolution in the relationship. Agilent sees great value in the MRM Assay kits provided by MRM Proteomics and so was very happy to be a co-marketing partner.
AB: How does your range of products complement Agilent’s mass spec platforms?
AM: MRM Proteomics kits were first developed on Agilent’s LC/MS QQQ which means methods were immediately available for other Agilent QQQ users. The kits allow Agilent’s QQQ users to assess instrument performance with a complex but well characterized standard.
AB: What do you see as the biggest challenges facing laboratories undertaking protein quantification and targeted proteomics? How do the MRM Proteomics' PeptiQuant MRM Assay Kits help alleviate these?
AM: Mass spectrometry (MS) is becoming increasingly important in biomedical and biological research, especially with the launch of large scale initiatives such as the Human Proteome Project, which depends on mass spectrometry as one of the main technology platforms for identifying, quantifying, and characterizing the human proteome. Targeted quantitative proteomics using Multiple Reaction Monitoring (MRM) sometimes called Selected Reaction Monitoring (SRM) is only one of the protein quantitation methods in use, but it is experiencing nearly exponential growth.
The mass spectrometry and proteomics communities currently lack standardized protocols and reagents (kits) to ensure high quality data that can be reproduced by laboratories across the world using different MS technologies. The Human Proteome Organization (HUPO) has recognized standardization of MS-based proteomics as critical for long-term success of omics programs.
Proteomics is evolving from a qualitative science to a quantitative science, and this transition is required if proteomics is going to successfully make the transition into a widely used and clinically-useful technique. Plasma is the most commonly-used biofluid for clinical analysis. It is also one of the most complex, due not only to the presence of more than 2000 proteins, but also the wide dynamic range of concentrations present, >1010. The challenge of "quality control" in proteomics data has been the subject of several HUPO and HPP focus groups, in addition to policy changes on the part of Molecular and Cellular Proteomics, one of the leading proteomics journals. Because of the large number of combinations of instruments, techniques, reagents, and software, this is a daunting prospect, but the concept of quality control or even "accreditation" is intriguing.
The idea behind the development of our PeptiQuant™ targeted proteomics quality control kits was to provide a first step towards standardisation and quality control of mass spectrometry based targeted quantitative proteomics. We envision utilization of these kits as a key component to fulfill the minimum requirement for quantitative proteomics experiments involved in the Human Proteome Project and other large scale proteomics projects.