Grant: Collaborative Health Research Projects

Proprotein convertases (PCs) and their substrates are important players in many human diseases includingcardiovascular 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 thatimpact 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 accuratemeasurement of the level of the different circulating isoforms is key to drug development and the treatment ofdiseases. Unfortunately, they are often present in minute amounts in circulation and have different bioactiveand/or inactive isoforms that need to be distinguished. Conventional antibody based detection approach haveprovided mitigated results. We propose instead to develop microfluidic technologies combined with massspectrometry 1) for the identification of PC substrates and 2) for the quantitative monitoring of some PCs andsubstrates in circulation. We will put in place a platform based on the microfluidic proteomic reactor coupledto 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 multiplereaction 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 theidentification substrates and for rapid and quantitative monitoring of circulating PCs and substrates, as well asa set of proprietary mass spectrometry- based assays.