Plasma alpha-D-mannosidase in mucolipidosis II and mucolipidosis III.
There is a marked increase in the acidic alpha-D-mannosidase in the plasma of a patient with mucolipidosis II and of a patient with mucolipidosis III. A small proportion (3--4%) of this acidic alpha-D-mannosidase does not bind to concanavalin A-Sepharose, suggesting an alteration in the glycosylation and some of the enzyme in these disorders. A slight elevation in intermediate alpha-D-mannosidase was also demonstrated in these samples by using a differential assay for the acidic and intermediate alpha-D-mannosidase activities. A combination of chromatography on concanavalin A-Sepharose and Sephadex G-200 showed that intermediate alpha-D-mannosidase components I2 and I4, which account for approximately 80% of the intermediate activity in normal plasma, were also present in ML II and ML III plasma. The minor intermediate alpha-D-mannosidase components in normal plasma, I1 and I3 were either present in small amounts or not detected. These results suggest that a defect in intermediate alpha-D-mannosidase is unlikely to be the primary defect in these disorders.
D000293:Adolescent; D002846:Chromatography, Affinity; D006801:Humans; D007223:Infant; D008297:Male; D008361:Mannosidases / Q000097:blood* / Q000302:isolation & purification; D009081:Mucolipidoses / Q000201:enzymology*
D008361:Mannosidases