Tuning into enzymes

Sugar-modified proteins, glycoproteins, account for more than half of our body's protein roster as well as a wide range of pharmaceuticals. But, the natural glycoproteins tend to have a non-uniform sugar component, whereas for research applications it would be simpler and easier if they were more regular in nature. Now, Carlo Unverzagt at the University of Bayreuth, in Germany, and colleagues have used a new strategy to synthesize ribonuclease C (RNase C), a glycosylated bovine pancreatic enzyme, with a sugar "antenna". They used "native chemical ligation" to build the molecule rather than conventional solid-phase peptide synthesis. The approach will extend the use of RNase C as a model of glycoproteins.