Open AccessHuman α‐ N ‐Acetylglucosaminidase
Author(s) -
FIGURA Kurt
Publication year - 1977
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1977.tb11909.x
Subject(s) - chemistry , exoglycosidase , heparan sulfate , isoelectric point , biochemistry , enzyme , isoelectric focusing , endocytosis , heparin , glycoside hydrolase , alpha (finance) , glycoprotein , cell , glycan , medicine , construct validity , nursing , patient satisfaction
Purified urinary α‐ N ‐acetylglucosaminidase acts as an exoglycosidase. The enzyme removes from heparan sulfate exclusively α‐glycosidically linked N ‐acetylglucosamine residues. The pH optimum of around 4.4 towards heparan sulfate and heparin is similar to that towards synthetic arylglycosides. Urinary α‐ N ‐acetylglucosaminidase can be separated by isoelectric focusing into multiple forms with p I values between 3.3 and 6.0. The multiple forms differ in their recognition and endocytosis by cultivated skin fibroblasts. Forms with p I values of 4.8 ± 0.3 respond best to endcytosis. From these forms up to 0.8 × 10 6 molecules may be recognized and taken up in an hour by a single cell. Sodium periodate treatment reduces the α‐ N ‐acetylglucosaminidase recognition by fibroblasts and suggests that the recognition sites on the enzyme are associated with its carbohydrate moiety. Attempts to modify the recognition of α‐ N ‐acetylglucosaminidase by pretreatment with purified glycosidases failed.