FLUORESCENT MODIFICATION OF THE MONOCLONAL ANTIBODIES OLIGOSACCHARIDES BY FLUORESCEIN-5-THIOSEMICARBAZIDE

Abstract

Introduction Monoclonal antibodies (Mabs) are a good tool for diagnosing human pathologies. They are used as conjugates with fluorescent and other dyes. The classical approach of creating such conjugates is reduced to chemical reactions using the protein base of the Mab. At the same time, for a number of Mabs, conjugate production is accompanied by embedding the label into the antigen binding site, which leads to a decrease or complete loss of the specific activity of the conjugate. To get out of this situation, the synthesis of fluorescent conjugates by methods of carbohydrate chemistry through spatially distant from the active center oligosaccharides of antibodies is proposed. Objective To obtain high activity ICO series Mab conjugates based on the reaction of covalent inclusion of the fluorescent label in the oligosaccharide sequence of the Mab. Materials and methods We used Mab series ICO of high purity. Oligosaccharides Mabs oxidized to aldehyde groups, were subjected to interaction with fluoriscine-5-thiosemicarboside, followed by the reduction of hydrazone derivative borgidrides. The resulting covalent conjugate was investigated in a flow cytometry. Results The synthesis of a fluorescent conjugate using monoclonal antibodies oligosaccharides was worked out. Modified monoclonal antibodies retain specific binding to target cells inherent in the native antibody. The resulting conjugates remained active for a long time during storage. Conclusion An alternative method for conjugation of immunofluorescent, allowing to obtain conjugates of high activity, has been developed.