Chemoenzymatic synthesis of spacer-linked oligosaccharides for the preparation of neoglycoproteins
作者:Raul Gonzalez Lio、Joachim Thiem
DOI:10.1016/s0008-6215(99)00073-7
日期:1999.4
In the present work, the combination of chemical and enzymatic methods to obtain neoglycoproteins is described. Three bovine serum albumin (BSA)-conjugates, BSA-[GalNAc alpha-], BSA-[Gal(beta 1-3)GalNAc(alpha-], and BSA-[Neu5Ac(alpha 2-3)Gal(beta 1-3)GalNAc(alpha-], were prepared, alpha GalNAc derivatives were galactosylated employing crude P-galactosidase from bovine testes. The use of oversaturated donor solutions (pNP beta Gal) enhanced the yields up to 60%. This method was verified using divalent structures as accepters, that rendered di- and tri-galactosylated products. Further treatment of the disaccharides with CMP-Neu5Ac and alpha 2-3 sialyltransferase from pork liver led to formation of trisaccharides. Finally, mono-, di-, and trisaccharides were coupled to BSA employing a thiolic group introduced into the protein for Michael addition to a maleinimide group in the spacer-ann of the saccharide components. The results were monitored by HPLC and MALDI-TOF. (C) 1999 Elsevier Science Ltd. All rights reserved.