| Abstract: | Golgi endo‐α‐mannosidase (G‐EM) catalyzes an alternative deglucosylation process for N‐glycans and plays important roles in the post‐endoplasmic reticulum (ER) quality control pathway. To understand the post‐ER quality control mechanism, we synthesized a tetrasaccharide probe for the detection of the hydrolytic activity of G‐EM based on a fluorescence quenching assay. The probe was labeled with an N‐methylanthraniloyl group as a reporter dye at the non‐reducing end and a 2,4‐dinitrophenyl group as a quencher at the reducing end. This probe is hydrolyzed to disaccharide derivatives by G‐EM, resulting in increased fluorescence intensity. Thus, the fluorescence signal is directly proportional to the amount of disaccharide derivative present, allowing the G‐EM activity to be evaluated easily and quantitatively. |
