ELECTROCHEMICAL DETECTION OF LECTIN USING A GALACTOSAMINE LABELED WITH DAUNOMYCIN

To detect a lectin from soybean, an electrochemical procedure was deve loped by the use of a labeling of galactosamine. Because the lectin ha s binding sites to galactosamine, galactosamine labeled with daunomyci n having electroactivity was prepared. When labeled galactosamine (LG) combines with lectin, the part of daunomycin is taken in the binding sites of the lectin and becomes electroinactive. Therefore, the concen tration of the lectin can be estimated by measuring the peak current o f the LG. On the other hand, a competitive reaction to the lectin of g alactosamine and the LG makes a detection of galactosamine possible. T his method has merit that does not require a separation procedure of t he free LG from the bound one. An effect of length of spacer between d aunomycin and galactosamine was also investigated. It was found that a dsorption of reagent on the electrode increased due to introduction of the spacer. Furthermore, the electrode response of the LG was influen ced by the type of the spacer. (C) 1998 Elsevier Science B.V. All righ ts reserved.