Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.20 (alpha-glucosidase)
 4,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chemical galactosylation of human liver tissue lysosomal alpha-glucosidase was carried out. As a result of the modification some physicochemical properties of the enzyme were altered, while its stability and catalytic activity were maintained. An ability of the galactosylated alpha-glucosidase to interact with asialoglycoprotein receptor from mice liver tissue was studied in vitro. The reaction required Ca2+. A specific inhibitor of the receptor, N-acetyl galactosamine, as well as high concentrations of native glycoproteins and neoglycoproteins containing terminal galactose inhibited the receptor binding of the 125I-galactosylated alpha-glucosidase. Native alpha-glucosidase was not bound with the receptor. Antireceptor antibodies inhibited similarly binding of both native ligand, asialoorosomucoid and the galactosylated alpha-glucosidase. These data on specific interaction between the galactosylated form of alpha-glucosidase and asialoglycoprotein receptor are discussed in connection with the problem of directed transport of the enzyme into liver parenchymatous cells by means of receptor-dependent endocytosis, which may be of importance in development of enzymotherapy of hereditary lysosomal enzymopathies.
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PMID:[Chemical galactosylation of acid alpha-glucosidase to provide directed transport of the enzyme into lysosomes of liver parenchymal cells]. 282 27

An asialoglycoprotein receptor was isolated from murine liver and purified more than 1600-fold using 2-fold affinity chromatography on asialoorosomucoid-Sepharose. The purified receptor did not interact with 125I-orosomucoid, but bound to 125I-asialoorosomucoid. The binding of the receptor to asialoorosomucoid was saturable. The dissociation constant of the receptor-asialoorosomucoid complex was 0.4 X 10(-9) M. The molecular mass of the receptor, as determined with the use of specific antibodies by the immunoblotting method, was 43 kDa. High concentrations of unlabeled asialoorosomucoid and of n-aminophenyl-beta-D-galactosyl derivatives of bovine serum albumin, ovalbumin and acid alpha-glucosidase from human liver inhibited the binding of the receptor to 125I-asialoorosomucoid almost completely. The binding of the receptor to 125I-galactolyzed alpha-glucosidase was pH-dependent, with the pH optimum at 8.0-9.0. It was shown that, as in the case of 125I-asialoorosomucoid, the binding of the 125I-galactosyl derivative of alpha-glucosidase occurred in the presence of Ca2+ and was inhibited by N-acetylgalactosamine. Glycoproteins containing galactose as a terminal residue inhibited the interaction of the receptor with 125I-galactolyzed alpha-glucosidase. The possibility of directed transport of the galactolyzed alpha-glucosidase derivative into parenchymous liver cells using receptor-mediated endocytosis is discussed.
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PMID:Interaction of hepatic asialoglycoprotein receptor with asialoorosomucoid and galactolyzed lysosomal alpha-glucosidase. 352 76