Fluorometric determination of sugars using fluorescein-labeled concanavalin A-glycogen conjugates.
The fluorescence of fluoresceinisothiocyanate-labeled concanavalin A (FITC-Con A) was quenched by forming an FITC-Con A-glycogen conjugate and dequenched upon addition of sugars to the conjugate solution due to disaggregation of the conjugate. However, fluorescence quenching was barely observed upon formation of FITC-Con A-dextran conjugate. The sugar-induced fluorescence response of the FITC-Con A-glycogen conjugate depended significantly on the type of sugar: methylated alpha-D: -glucose and alpha-D: -mannose both induced high and rapid responses, while the responses to D: -mannose and D: -glucose were moderate. In contrast, no response was observed in the presence of D: -galactose due to a lack of affinity to Con A. Thus, it is apparent that D: -glucose and other sugars can be detected via the fluorescence of the FITC-Con A-glycogen conjugate.
Sato
Katsuhiko
K
Graduate School of Pharmaceutical Sciences, Tohoku University, Aramaki, Aoba-ku, Sendai, 980-8578, Japan. junanzai@mail.pharm.tohoku.ac.jp
Anzai
Jun-Ichi
J
D015374:Biosensing Techniques; D003208:Concanavalin A / Q000737:chemistry / Q000378:metabolism*; D003911:Dextrans / Q000032:analysis / Q000378:metabolism; D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry*; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry*; D005947:Glucose / Q000032:analysis* / Q000378:metabolism; D006003:Glycogen / Q000737:chemistry* / Q000378:metabolism
D003911:Dextrans; D005456:Fluorescent Dyes; D003208:Concanavalin A; D006003:Glycogen; D016650:Fluorescein-5-isothiocyanate; D005947:Glucose