Grant: Collaborative Health Research Projects (NSERC partnered)

"Proprotein convertases (PCs) and their substrates are important players in many human diseases including cardiovascular diseases, neurodegenerative diseases, mental health, cancer/metastasis and viral infections. Some convertases (PCSK9) and PC-substrates are secreted in circulation and have local or distal effects that impact human health. Changes in their circulating isoforms and levels can have drastic effects on health. Difference in isoforms due to single cleavage can lead to gain or loss of function. Therefore, the accurate measurement of the level of the different circulating isoforms is key to drug development and the treatment of diseases. Unfortunately, they are often present in minute amounts in circulation and have different bioactive and/or inactive isoforms that need to be distinguished. Conventional antibody based detection approach have provided mitigated results. We propose instead to develop microfluidic technologies combined with mass spectrometry 1) for the identification of PC substrates and 2) for the quantitative monitoring of some PCs and substrates in circulation. We will put in place a platform based on the microfluidic proteomic reactor coupled to mass spectrometry for the discovery of novel PC substrates, with an initial focus on the substrates of PC7. As well, we will develop another platform based on larger-capacity proteomic reactor coupled to multiple reaction monitoring (MRM) mass spectrometry for the rapid and absolute quantitation of circulating PCs (PCSK9) and circulating PC substrates. The outcome of this project will be: Novel platforms for the identification substrates and for rapid and quantitative monitoring of circulating PCs and substrates, as well as a set of proprietary mass spectrometry- based assays."