ENGINEERING PROTEINS THAT BIND TO CELL-SURFACE CARBOHYDRATES

Carbohydrate residues covalently linked to plasma membrane proteins an d lipids often provide specific markers at the cell surface. Tradition ally such carbohydrate structures have been identified using antibodie s and lectins. However problems of affinity and lack of specificity ha ve restricted their usefulness. Protein engineering offers a way round these difficulties. In the case of some specialised cell surface carb ohydrate structures, such as polysialic acid, enzymes may be useful an alytical tools. Endosialidases specific for polysialic acid have recen tly been cloned and sequenced. (C) 1997 Elsevier Science B.V.