PMSE 113 |
| The ability of sugar multivalent ligands of interacting with lectins and cells is strongly dependent on their size, shape, structure and epitope binding density. For ligand comparative studies it is therefore of importance to have a set of synthetic tools that allows for the synthesis of libraries of polymers having identical macromolecular features, with the relative density of epitope binding units being the only variable. Post-polymerization processes appear to be the only was for achieving this goal, as long as extremely efficient grafting processes are available. In this respect, the use of “clickable” polymers is very promising. In the present work, glycoconjugate was obtained by reaction of maleimide-terminated display with BSA . Several reaction conditions and purification protocols were explored for the conjugation reaction. In particular, both an excess of glycopolymer and BSA protein, 10:1 and 1:10 mol / mol respectively, were successfully employed. In the former case, the excess of unreacted maleimide polymer was removed by repeated SEC purifications, while unreacted BSA and BSA dimer were separated by affinity chromatography using an agarose-immobilized Concanavalin A (Con A) column. Con A is a 26 kDa leptin, (normally forming dimers or tetramers depending on pH) extracted from Jack Beans that specifically recognize a-mannopyranoside sugar moieties. When the mixture obtained from SEC purification was passed through the affinity chromatography column, only the bioconjugate was able to selectively interact with the Con A, while the BSA and BSA dimer were rapidly eluted . Bioconjugate was then released from the column by simply washing the latter with a 1.0 M solution of D-mannose, a monovalent competitive ligand for Con A. |
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Polypeptide and Protein Materials
8:00 AM-11:40 AM, Monday, August 20, 2007 Westin Boston Waterfront -- Commonwealth Blrm C, Oral
Division of Polymeric Materials: Science & Engineering |