A group of Ontario-based scientists has developed a new approach for protein quantification based on AB Sciex Qtrap and Eksigent technologies with multiple-reaction monitoring (MRM).
The approach enables scientists to assess the time course of the protein interactions associated with specific cellular responses, improving the understanding of signalling pathways implicated in cancer and other complex illnesses.
The study was published online in the 'Nature Biotechnology' journal and highlights the combination of standard affinity purification (AP) with MRM, which is also known as selective reaction monitoring (SRM).
Prior to the study, researchers have had little quantitative data regarding the kinetics with which protein networks assemble and dissolve to generate specific cellular responses.
It has been particularly difficult to assess the role and effects of adaptor proteins that link activated receptors to their cytoplasmic effectors.
The scientists, from the Samuel Lunenfeld Research Institute of Mount Sinai Hospital, collaborated with AB Sciex scientists to utilise the Qtrap 5500 system coupled to an Eksigent NanoLC Ultra and CHIPLC nanoflex liquid chromatography system to design a new approach, which they used to investigate changes in protein interactions with the adaptor protein GRB2, an important hub in growth factor signalling.
Large numbers of proteins, as well as the dynamics with which they react, can be measured and quantified with the AP-ARM method, the researchers said.
The Qtrap 5500 system combines quantitative and qualitative analysis on a single platform, integrating a triple quadrupole for quantitative analysis with a linear accelerator trap to confirm results within the same experiment.
It is suitable for biomarker and proteomics applications.