Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.1.7 (acetylcholinesterase)
 28,390 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Plasma membrane receptors are crucial for nonself tissue recognition. Using concanavalin A (Con A), wheat germ agglutinin, peanut agglutinin, soybean agglutinin (SBA), and winged pea agglutinin, five lectin-binding receptor molecules have been recognized on the plasma membrane of the granulocyte (immunocyte) of the horseshoe crab, Limulus polyphemus. Only Con A and SBA caused capping of surface receptors. On the basis of the known functions of these lectin-binding receptor molecules in other invertebrates and vertebrates, their roles in phagocytosis, encapsulation, signaling, and possibly in complement pathway activation are postulated. In addition to lectin-binding receptors, Na+,K(+)-ATPase and acetylcholinesterase were detected on the plasma membrane. Because Limulus dates back to some 200 million years, the antiquity of these molecules is suggested. Furthermore, some of the lectin-binding surface receptors have the potential to be used as markers to separate different kinds of hemocytes in higher arthropods and to distinguish between normal and neoplastic cells in humans.
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PMID:Lectin-binding receptors, Na+,K(+)-ATPase, and acetylcholinesterase on immunocyte plasma membrane of Limulus polyphemus. 184 29

We studied 5'-nucleotidase in preparations of synaptic plasma membranes from bovine caudate nucleus. The best substrates for this membrane-bound enzyme were purine nucleotides, particularly 5'AMP. Effects of metal cations and chelating agents suggest that 5'-nucleotidase is a metalloprotein. Optimal conditions for solubilization of the 5'-nucleotidase were found by using a low concentration of the zwitterionic detergent sulfobetaine 14. In contrast, another membrane-bound enzyme, acetylcholinesterase, was not solubilized under these conditions, but only in the presence of Triton X-100. The effects of lectins (concanavalin A, Lens culinaris agglutinin, wheat germ agglutinin, and Limulus polyphemus agglutinin) showed that both enzymes are glycoproteins. Sequential hydrolysis with specific glycosidases produced modifications of the effect of lectins on these enzymes. The results suggest the presence of a complex-type glycosylation, with a fucose residue on the internal N-acetyl-D-glucosamine of the pentasaccharide core.
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PMID:5'-Nucleotidase from bovine caudate nucleus synaptic plasma membranes: specificity for substrates and cations; study of the carbohydrate moiety by glycosidases. 632 59

The binding of 125I-labelled alpha-bungarotoxin in the central nervous system of the horseshoe crab, Limulus polyphemus, was investigated. Comparative binding studies in various tissues of L. polyphemus demonstrated a selective association of the toxin with nervous tissues. The greatest enrichment of toxin binding in subcellular fractions of brain tissue was observed in a fraction enriched in mitochondria and acetylcholinesterase-containing membranes. Autoradiographic studies revealed the localization of alpha-bungarotoxin binding to the longitudinal connectives and neuropile regions of the abdominal ganglia. Three toxin binding components with approximate sedimentation coefficients of 9 S, 15.4 S and 17.4 S were present in solubilized extracts of brain tissue. 125I-labeled alpha-bungarotoxin binding to these components was inhibited 72%, 47%, 9% and 0% by 10 microM concentrations of (+)-tubocurarine, nicotine, scopolamine and pilocarpine, respectively. The apparent formation of the 15.4 S and 17.4 S proteins from the 9 S protein was obtained. The 15.4 S and 17.4 S components are suggested as aggregates of the 9 S protein. This 9 S protein is proposed as an acetylcholine receptor from the central nervous system of L. polyphemus.
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PMID:Alpha-bungarotoxin binding in the central nervous system of Limulus polyphemus. 743 77