Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.5 (5'-nucleotidase)
 3,167 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Glycosylation and carbohydrate processing of ecto-5'-nucleotidase were studied in cultured human chorionic cells using metabolic labelling and immunoprecipitation with monoclonal antibodies. Tunicamycin blocks glycosylation altogether leading to a reduction in molecular mass of 9,500 Da. The same result is obtained by digesting the mature 72,000-Da protein with endoglycosidase F. Using various inhibitors of the carbohydrate-trimming reactions like deoxynojirimycin, deoxymannojirimycin and swainsonine smaller molecular mass reductions are observed and the oligosaccharide side chains are kept in a configuration sensitive to endoglycosidase H digestion. Digestion of mature 5'-nucleotidase with endoglycosidase H leads to a much smaller (2,000 Da) reduction in molecular mass. It is calculated that, in addition to the phosphatidylinositol-glycan anchor structure, ecto-5'-nucleotidase of human chorionic cells should carry 4 oligosaccharide side chains per subunit, 3 of which should be of the complex and one of the high mannose type. Interference with carbohydrate processing by various inhibitors does not seem to influence the distribution of ecto-5'-nucleotidase between the cell surface and intracellular membranes nor does it block the transfer of the enzyme to the phosphatidylinositol glycan anchor.
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PMID:Glycosylation and processing of carbohydrate side chains of ecto-5'-nucleotidase in cultured human chorionic cells. 214 Feb 64

The synthesis and degradation of 5'-nucleotidase has been studied in rat hepatocytes. Primary cultures of rat hepatocytes were established with the cells showing evidence of polarity after 24-36 h in culture. After a 30 h lag period 5'-nucleotidase activity increased to a plateau level similar to the activity found in whole liver. The half life of the enzyme after reaching the plateau of activity was 22.8 h. Pulse-chase biosynthetic labelling studies of 5'-nucleotidase in the cultured hepatocytes using [35S]methionine showed that the 5'-nucleotidase monomer was synthesised as an Mr 67,000 form which was converted to the mature Mr 72,000 form. [35S]Methionine labelling studies in the presence of tunicamycin showed that the unglycosylated protein monomer was an Mr 57,000 form. The immature Mr 67,000 form of 5'-nucleotidase was sensitive to endoglycosidase H, whereas the mature form was sensitive only to endoglycosidase F. The data presented are consistent with 5'-nucleotidase in a polarised cell being synthesised and processed like other membrane glycoproteins, in contrast to earlier reports.
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PMID:The synthesis and turnover of 5'-nucleotidase in primary cultured hepatocytes. 302 39