A Fluorescence-Based Competitive Antibody Binding Assay for Kynurenine, a Potential Biomarker of Kidney Transplant
Max Borgolte1,2, Isabel Quint1,3, Lars Kaiser1,4
1Institute of Precision Medicine, Furtwangen University, Jakob-Kienzle Str. 17, 78054 Villingen-Schwenningen, Germany.
Abstract:
Kynurenine is a tryptophan metabolite linked to several inflammatory processes including transplant failure, a significant challenge in transplant medicine. The detection of small molecules such as kynurenine, however, is often complex and time consuming. Herein, we report the successful synthesis of a fluorescently labelled kynurenine derivative, showing proper fluorescence and anti-kynurenine antibody binding behavior in a magnetic bead immunoassay (MIA). The fluorescent kynurenine-rhodamine B conjugate shows a KD-value of 5.9 µM as well as IC50 values of 4.0 µM in PBS and 10.2 µM in saliva. We thus introduce a rapid test for kynurenine as a potential biomarker for kidney transplant failure.
