Physikron technology, positioned between instrumentation and the identification software, brings an innovative and complementary solution to improve the performance of tandem spectrometry.
Thanks to patented algorithms, Physikron technology dramatically improves the number of peptides and proteins identified during a LC/MS/MS acquisition.
Between the measuring instrument and identification software, Physikron technology is made of algorithms able to analyze the primary (precursor) MS spectrum and the secondary MS/MS spectra from shotgun experiments.
Physikron technology analyzes dissociated fragments from all the primary masses included in the selection window. Whereas in a standard approach, only one MS primary mass is used per MS/MS spectrum, Physikron technology produces as many secondary spectra as primary masses in the selection window. Each secondary MS/MS spectrum is thus associated with a primary mass.
Physikron Technology Proteomics Applications
- Biomarker identifications
- Discovery of new therapeutic targets
- Study of Post Translational Modifications (PTMs)
- Cellular and tissular profiling
- Complex samples analysis
- Environmental testing
- Food and beverage testing
- Physikron technology increases significantly the number of proteins identified and the sequence coverage per identified protein
- It does not depend on the type of mass spectrometer used
- It is compatible with every instrument producing high resolution MS/MS mass spectra (Q-TOF, LTQ-Orbitrap, FTICR, IT-TOF…)
- Sample consumption to produce each MS/MS spectrum is reduced
- The width of the primary mass selection corresponds to the instrumental MS resolution of the instrument used
- Setting up Physikron technology is simple and does not require any hardware change
By multiplying the number of secondary spectra by a factor between 2 and 5, Physikron technology increases the MS/MS throughput by the same factor. Fragments that correspond to a specific primary mass are filtered. As a result, the gain in the number of identified proteins by Physikron technology reaches between 25% and 80% (depending on the type of spectrometer used and the complexity of the sample) for the same data compared with standard analysis not using Physikron’s technology.
As example of the performances of the Physikron technology, figure 1 represents the histogram of the number of proteins coming from the same Human Cells sample. The mass spectrometer used is a LC-ESI-LTQ-Orbitrap Velos (Thermo Fischer) and the search engine is Mascot. Data were supplied by Dr Denis Loyaux (System Biology 1 / Exploratory Unit, Sanofi-Aventis, Toulouse France).
Figure 1: Gain achieved on the identification of proteins thanks to Physikron Technology. 1 µg of a human cell lysates sample was analyzed (trypsin digest). The instrument used is a LC-ESI-LTQ-Orbitrap Velos in HCD MS-MS mode. The acquisition time was of 3 hours (HPLC). The precision was of 4 ppm for the MS data produced (30000 MS resolution) and 10 ppm for the MS/MS data produced (7500 MS-MS resolution).
Number of proteins identified from a standard and Physikron analysis compared as a function of the precursor mass window width. MS/MS data shown on the plot are produced from a Human Cell sample by a LC-ESI-LTQ-Orbitrap Velos (Thermo Fisher) in the MS/MS HCD high resolution mode. The search engine used is Mascot. Data were supplied by Dr Denis Loyaux (System Biology 1 / Exploratory Unit, Sanofi-Aventis, Toulouse France).
Figure 2 : Evolution of the number of proteins identified according to the width of the selection window for the precursor mass
Physikron technology with the Velos HCD high resolution mode identifies more proteins than the standard LTQ low resolution mode. It allows for the advantages of HCD standard mode (high resolution with small mass fragments not detected in LTQ mode).