A new way to attach sugars to proteins is reported online this week in Nature Chemical Biology. As these particular sugar/protein combinations are key to controlling viral infections and are involved in numerous diseases, such as muscular dystrophy, this work has immediate practical applications in biopharma and glycoprotein research.
It is typically much easier to use bacterial cells to produce large quantities of a desired protein than mammalian cells. However, some proteins, called glycoproteins, also need to have a sugar chain attached to the protein sequence in order to be fully functional. The sugars that can be attached using bacterial cells are significantly different than those found in mammalian cells, therefore limiting the extent to which these helpful bacterial cell cultures can be used to make natural mammalian glycoproteins.
Now Lai-Xi Wang, Markus Aebi and colleagues have created a hybrid E. coli that contains genes from C. jejuni ― another kind of bacteria. These genes work together with normal E. coli genes to create the first sugar link present in mammalian glycoproteins. Though additional, unnecessary sugars are also placed on the sugar chain in cell culture, the team demonstrates that it is easy to use known methods in the lab to take off these extra sugars and replace them with others.
This combined methodology now makes it possible to create a large quantity of correctly-modified glycoproteins for further biological studies or for pharmaceutical preparations.