Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.1 (alkaline phosphatase)
 47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ligatin is a filamentous, baseplate protein that binds and localizes peripheral glycoproteins to the external cell surface. Glycoproteins coisolated with ligatin from embryonic chicken neural retina and radiolabeled with 32P are retained by an affinity column containing covalently bound retinal ligatin. Elution is achieved preferentially by alpha-glucose 1-phosphate and, to a limited extent, by mannose 6-phosphate. Treatment with endo-beta-N-acetylglucosaminidase H prevents the proteins from binding to the column and results in the release of high-mannose-type oligosaccharides containing 32P. The simplest of these oligosaccharides is unaffected by alkaline phosphatase unless the treatment is preceded by mild acid hydrolysis. Enzymatic and chemical analyses suggest that the phosphate is present in phosphodiester bonds linking penultimate mannose residues to terminal glucose residues.
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PMID:Retinal ligatin recognizes glycoproteins bearing oligosaccharides terminating in phosphodiester-linked glucose. 680 52

Ligatin, a receptor that recognizes phosphorylated sugars, was isolated from plasma membranes of mouse macrophages, rat ileum, and rat brain. Several acidic hydrolases including N-acetyl beta-D-glucosaminidase (beta-NAG) were solubilized with this receptor. The solubilized beta-NAG bound to ligatin in vitro as demonstrated by affinity chromatography using the immobilized receptor. beta-N-Acetyl D-glucosaminidase-ligatin complexes were dissociated by low concentrations of mannose 6-phosphate (Man6P) and/or glucose 1-phosphate (Glc 1P). The effectiveness of these two phosphomonosaccharides varied depending on the source of the enzyme: ileal beta-NAG-ligatin complexes showed a four-fold preferential dissociation with Man6P; macrophage complexes showed a 160-fold preferential dissociation with Glc 1P. Brain complexes dissociated with nearly equal preference for Man6P and Glc 1P. Heterologous complexes displayed the specificity characteristic of the source of the enzyme regardless of the source of the ligatin. Treatment of the solubilized hydrolases with endoglucosaminidase H released phosphorous-32 label from these enzymes and prevented binding of beta-NAG to ligatin. However, treatment of the solubilized hydrolases with alkaline phosphatase reduced the binding of beta-NAG to ligatin by no more than 30%. This apparent resistance of beta-NAG to dephosphorylation was consistent with the chromatographic behavior of QAE of 3H-labeled acidic oligosaccharides isolated from the solubilized hydrolases. The oligosaccharides that contain phosphorylated hexose were less acidic than phosphomonoesters and were insensitive to alkaline phosphatase until subjected to acid hydrolysis. These results suggested the presence of a phosphodiester on beta-NAG analogous to the NAC glucosamine 1 P6 mannose present on beta-glucuronidase isolated from mouse lymphoma cells (Tabas I, Kornfield, S: J Biol Chem 255: 6633, 1980).
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PMID:Ligatin binds phosphohexose residues on acidic hydrolases. 729 41