Mannosidosis in Angus cattle. The enzymic defect.
Normal calf alpha-mannosidase activity exists in at least three forms separable by chromatography on DEAE-cellulose and by starch-gel electrophoresis. Two components, A and B, have optimum activity between pH3.75 and 4.75, but component C has an optimum of pH6.6. Components A and B are virtually absent from the tissues of a calf with mannosidosis and the residual activity is due to component C. The acidic and neutral forms of alpha-mannosidase differ in their molecular weights and sensitivity to EDTA, Zn(2+), Co(2+) and Mn(2+). An acidic alpha-mannosidase component (pH optimum 4.0) accounts for most of the activity in normal plasma but it is absent from the plasma of a calf with mannosidosis. Although the acidic alpha-mannosidase component is probably related to tissue components A and B, it can be distinguished from them by ion-exchange chromatography and gel filtration. The optimum pH of the low residual activity in the plasma from a calf with mannosidosis is pH5.5-5.75. The results support the hypothesis that Angus-cattle mannosidosis is a storage disease caused by a deficiency of lysosomal acidic alpha-mannosidase activity.
D000818:Animals; D001921:Brain / Q000201:enzymology; D002239:Carbohydrate Metabolism, Inborn Errors / Q000201:enzymology*; D002417:Cattle / Q000378:metabolism*; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D003035:Cobalt / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D004592:Electrophoresis, Starch Gel; D006026:Glycoside Hydrolases / Q000097:blood / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007527:Isoenzymes / Q000378:metabolism; D007668:Kidney / Q000201:enzymology; D008099:Liver / Q000201:enzymology; D008198:Lymph Nodes / Q000201:enzymology; D008247:Lysosomes / Q000201:enzymology; D008345:Manganese / Q000494:pharmacology; D008358:Mannose; D008970:Molecular Weight; D009928:Organ Specificity; D013050:Spectrometry, Fluorescence; D013154:Spleen / Q000201:enzymology; D015032:Zinc / Q000494:pharmacology
D007527:Isoenzymes; D003035:Cobalt; D008345:Manganese; D004492:Edetic Acid; D006026:Glycoside Hydrolases; D015032:Zinc; D008358:Mannose