The importance of changing proteins to glycoproteins
Advancing knowledge about changes to proteins after they have been produced in tissues has highlighted the importance of glycosylation. Addition of a saccharide element (the glycan) to a protein results in formation of a glycoprotein, a group of molecules that have a range of functions including roles in cell structure and self recognition. Project scientists set up a 'carousel' for the results of samples' diagnosis through a series of laboratories. This included a database for results and tools for testing and diagnosis. To raise awareness, the network disseminated information to clinicians and professionals. Part of this initiative involved four annual meetings for doctors and researchers. Referral centres set up across Europe helped to collect samples as well as offer support to physicians and CDG individuals and their families. Laboratories in the diagnostic carousel were able to introduce novel testing procedures. New technologies included a test for O-glycan defects. O-glycan is important physiologically in many roles, the main one being in secretions from cell surfaces and body fluids. Ion-mobility and mass spectrometry were used to analyse N-glycans as well as identify genes related to CDG. Overall, more than 20,000 patients with unexplained symptoms were tested for CDG. Tests revealed several different new types of glycosylation disorder, a substantial success for the project. Around 200 unsolved cases represent a pool for the collection of new samples that may yet reveal more about this emerging group of diseases. Further work lies ahead as the biochemical pathways are very complex and genetic typing is difficult. Building on the project results and defining more chemical cascades promises to deliver new therapies.