MOLECULAR-DYNAMICS SIMULATIONS OF A GLYCOPROTEIN - THE LECTIN FROM ERYTHRINA CORALLODENDRON

The structure of the lectin from Erythrina corallodendron (EcorL) has recently been solved crystallographically, with the oligosaccharide po rtion of this glycoprotein unusually well resolved. In general, the st ructure and dynamics of the oligosaccharides in glycoproteins are poor ly understood. The crystal structure of EcorL provides an opportunity to probe the conformational properties of the oligosaccharide using co mputer modeling. Two 300 ps molecular dynamics simulations are reporte d of the oligosaccharide in solution isolated from the protein and bou nd to the protein and surrounded by water. The motions of the oligosac charide are similar both free in solution and bonded to the protein. H owever, different parts of the glycosidic linkage conformational space have been explored by key component disaccharides in the two environm ents. The disaccharide of the ''core'' region shows greater flexibilit y in the isolated oligosaccharide than in the same region in the bound oligosaccharide. Because of the short length of these simulations, it could not be determined whether these differences are due to random c hance or are a true reflection of the influence of the protein on the conformation of the oligosaccharide. (C) 1997 Elsevier Science B.V.