Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Endogenous ligands for the hepatic lectin which is specific for mannose and N-acetylglucosamine (mannan-binding protein, MBP) were isolated from rat liver rough microsomes and primary cultured hepatocytes by affinity chromatography on an immobilized MBP column. Western blotting using specific antisera revealed that serum glycoproteins, alpha 1-macroglobulin, alpha 1-antitrypsin, and alpha 1-acid glycoprotein, and a lysosomal enzyme, beta-glucuronidase were the major constituents of the endogenous ligands. These endogenous ligands consisted of high mannose-type oligosaccharides of Man9GlcNAc2 and Man8GlcNAc2, and had rapid turnover rates with an average half-life of 45 min, indicating that they were mainly composed of biosynthetic intermediates of glycoproteins. In view of the identification of the endogenous ligands as the biosynthetic intermediates of glycoproteins, the possible functions of the intracellular lectin are discussed in relation to the intracellular transport of glycoproteins.
 ...
PMID:Isolation and characterization of endogenous ligands for liver mannan-binding protein. 245 42

Oligosaccharides of a non-oligomannoside type were released from porcine alpha-mannosidase by hydrazinolysis, and were fractionated into at least 15 homogeneous oligosaccharides. Most of them are oligosaccharides with galactose and N-acetylglucosamine residues attached to a common core, alpha Man2 beta Man beta GlcNAc(+/- alpha-L-Fuc)beta GlcNAc. About 50% of the oligosaccharides contain one or two outer chains composed of one beta-linked N-acetylglucosamine and two beta-linked galactose residues attached to the core portions, and the others seem to be metabolic intermediates. Based on the results of studies on the binding of alpha-mannosidase to RCA (Ricinus communis agglutinin) I-agarose and MBP (mannan-binding protein)-Sepharose, which are specific for glycoproteins possessing N-acetyllactosamine-type and oligomannoside-type (including oligomannosides with N-acetylglucosamine at the reducing termini) oligosaccharides, respectively, about 85% of the enzyme molecules were found to have both types of oligosaccharides. Similarly, it was shown that of the several acid hydrolases present in the lysosomes purified from rat liver, only alpha-mannosidase has both types of oligosaccharides, and the greater parts of beta-glucuronidase, acid phosphatase and beta-N-acetylhexosaminidase seem to have only oligomannoside-type oligosaccharides.
 ...
PMID:Structures of galactose-containing oligosaccharides of alpha-mannosidase from porcine kidney. 309 80