[Study on the enzymatic properties of N-acetyl-beta, D-glucosaminidase A (NAG A) from the tissue of renal cell carcinomas: comparison of the enzymatic properties with those of normal renal tissues, with special regard to sugar-chain structures].
The enzymatic properties of N-acetyl-beta,D-glucosaminidase A (NAG A) partially purified from the tissues of seven cases of human renal cell carcinomas were studied individually and compared with those of normal renal tissues. In the carcinoma tissues, the Km value of the enzyme toward a synthetic glucosaminide substrate was 0.180 +/- 0.07 mM, the optimal pH of the enzyme ranged from pH 4.7 to 4.9 and the enzyme showed fairly stable for metal ions. These enzyme characteristics were similar to those of the normal tissues. On the contrary, the sugar-chain structures of the enzyme from the carcinoma tissues studied by lectin affinity chromatographies, were statistically different from those of the normal tissues. Namely, both complex type of sugar-chains as well as hybrid type sugar-chains without fucose linkage to the innermost N-acetylglucosamine (GlcNAc) were significantly increased in the enzyme from the carcinoma tissues, while high mannose type sugar-chains and hybrid type sugar-chains with fucose linkage to the innermost GlcNAc were significantly decreased in the carcinoma tissues compared to the normal tissues. These results indicate that the processing of sugar-chains of the enzyme has possibly changed in the carcinoma tissues.
Yoshida
K
K
Department of Urology, Saitama Medical Center, Saitama Medical School.
D000118:Acetylglucosaminidase / Q000737:chemistry* / Q000302:isolation & purification; D002240:Carbohydrate Sequence; D002846:Chromatography, Affinity; D006801:Humans; D007668:Kidney / Q000201:enzymology*; D007680:Kidney Neoplasms / Q000201:enzymology*; D008969:Molecular Sequence Data
D000118:Acetylglucosaminidase