The multiple forms of alpha-D-mannosidase in human plasma.
The acidic alpha-D-mannosidase in human plasma closely resembles liver acidic alpha-D-mannosidase in its affinity for concanavalin A-Sepharose, molecular weight and resolution into multiple components on DEAE-cellulose. A combination of chromatography on concanavalin A-Sepharose and gel filtration on Sephadex G-200 and Sepharose 6B suggests that four forms of intermediate alpha-D-mannosidase, which differ either in their molecular weight of affinity for concanavalin A, exist in human plasma. A practical classification and nomenclature for the multiple forms of intermediate alpha-D-mannosidase in plasma based on molecular weight and affinity for concanavalin A is proposed. Multiple forms of intermediate alpha-D-mannosidase were also observed by ion-exchange chromatography on DEAE-cellulose, but there was not a simple correlation between these forms and those obtained with the other separation procedures. The form of intermediate alpha-D-mannosidase least abundant in plasma, approx. 7% of the activity, has very similar properties to the neutral alpha-D-mannosidase in human liver. In contrast, the other three forms of intermediate alpha-D-mannosidase, which account for over 90% of the activity, do not appear to be present in liver, except perhaps in trace amounts.
D002239:Carbohydrate Metabolism, Inborn Errors / Q000097:blood / Q000201:enzymology; D002847:Chromatography, Agarose; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D003208:Concanavalin A; D006801:Humans; D007527:Isoenzymes / Q000097:blood*; D008099:Liver / Q000201:enzymology; D008358:Mannose / Q000378:metabolism; D008361:Mannosidases / Q000097:blood*
D007527:Isoenzymes; D003208:Concanavalin A; D008361:Mannosidases; D008358:Mannose