PROTEIN CARBOHYDRATE INTERACTIONS

X-ray structures of protein-carbohydrate complexes reported this year confirm well established rules of protein-carbohydrate interactions: s tabilization 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 mutagen esis experiments. In contrast, new insights have emerged regarding bio logically and catalytically relevant carbohydrate-metal interactions. Carbohydrate flexibility and ring opening play crucial roles in cataly sis, as demonstrated by the structures of neuraminidase and xylose iso merase.