Demonstration and some properties of N-acetyl-beta,D-hexosaminidase (HEX) C isoenzyme in human renal tissues: relative increase of HEX C activity in renal cell carcinoma.
The present study has demonstrated the presence of hexosaminidase (HEX) C activity in human renal tissues by an electrophoretic method. At the same time, its enzymatic properties, obtained as unbound fraction of renal tissue extracts passed through a concanavalin A Sepharose column, have been compared with those of HEX A and B. HEX C had the fastest electrophoretic mobility among HEX isoenzymes. The optimal pH of HEX C was 6.5, while that of HEX A and B was 4.9. The Km value of HEX C for synthetic glucosaminide substrate was 1.16 mmol/l, while that of HEX A and B was 0.18 mmol/l and 0.22 mmol/l, respectively. HEX C was inactive for a synthetic galactosaminide substrate, while HEX A and B were active. The percentage of HEX C activity to the total was 7.9 +/- 2.9% and 13.8 +/- 3.0% in the normal and the neoplastic tissues, respectively. A significant difference was observed between them (P < 0.01). These results indicate that the enzymatic properties of HEX C is quite different from those of A and B and also suggest that the determination of HEX C may become one of the useful clinical markers of the human renal cell carcinoma.
Yoshida
K
K
Department of Urology, Saitama Medical Center of Saitama Medical School, Japan.
D000328:Adult; D000368:Aged; D002292:Carcinoma, Renal Cell / Q000201:enzymology*; D002847:Chromatography, Agarose; D002848:Chromatography, DEAE-Cellulose; D004588:Electrophoresis, Cellulose Acetate; D054818:Hexosaminidase A; D006801:Humans; D007668:Kidney / Q000201:enzymology*; D007680:Kidney Neoplasms / Q000201:enzymology*; D008875:Middle Aged; D001619:beta-N-Acetylhexosaminidases / Q000032:analysis* / Q000378:metabolism
D054818:Hexosaminidase A; D001619:beta-N-Acetylhexosaminidases