PROTEIN CARBOHYDRATE INTERACTIONS

X-ray structures of protein-carbohydrate complexes reported this year confirm well established rules of protein-carbohydrate interactions: stabilization through a network of hydrogen bonds often involving water molecules, and hydrophobic interactions. The importance of the latter interactions have been tested in a few cases by site-directed mutagenesis experiments. In contrast, new insights have emerged regarding biologically and catalytically relevant carbohydrate-metal interactions. Carbohydrate flexibility and ring opening play crucial roles in catalysis, as demonstrated by the structures of neuraminidase and xylose isomerase.