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)

Ibotenic acid was injected unilaterally into the baboon caudate-putamen (CP) to achieve a neural degeneration model in the primate, with a neuropathology similar to Huntington's disease. Four to six weeks later injections of cell suspensions of striatal precursor cells, obtained by dissection of the fetal rat striatal region (13-15 days gestational age), were made into the excitotoxically lesioned CP of 3 baboons immunosuppressed by Cyclosporin A. Morphological analysis indicated that in one of the baboons, which had the largest lesion of the CP and the shortest survival time (6 weeks after implantation), there was a surviving striatal implant. The implanted neurons grew in high densities in cellular aggregates within the host gliotic CP. These neurons had a neuronal size phenotypical for rat striatum, i.e. on average about a 25% smaller neuronal cell diameter than a similar population in the baboon caudate-putamen. Glial-fibrillary-acid-protein immunoreactivity was present on large astrocytes within the striatal implant, with a distinct border towards the lesion-induced astrogliosis of the host. Neuronal markers for acetylcholinesterase and Leu-enkephalin were distributed in a typical patchy manner in the striatal implants along with fiber staining for tyrosine-hydroxylase-like immunoreactivity (TH) possibly derived from afferent host dopaminergic axons. Some of these fibers in the implants came from intrinsic TH-positive neuronal somata, probably of neocortical fetal origin and transiently expressing the enzyme. In conclusion, the results indicate that neuronal replacement can be achieved by cross-species implantation of fetal striatal precursor cells to the previously neuron depleted primate CP under immunosuppression but that the survival and growth of such implants may be variable and subject to unfavourable trophic conditions.
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PMID:A primate model of Huntington's disease: cross-species implantation of striatal precursor cells to the excitotoxically lesioned baboon caudate-putamen. 252 13

Acetylcholinesterase (AChE, EC 3.1.1.7) purified from the electric organ of eel possesses a protease activity resembling that of a neuropeptide processing enzyme. To examine whether any mammalian AChEs possess a similar protease activity, the enzyme was purified, 110,000-fold from foetal bovine serum. Purified serum AChE cleaved 2 synthetic peptide substrates in a manner resembling the combined actions of trypsin-like and carboxypeptidase B-like enzymes. A synthetic fragment of preproenkephalin A (residues 97-107) containing a complete methionine-enkephalin sequence was cleaved by serum AChE to yield free methionine-enkephalin. The carboxypeptidase action of AChE was weakly stimulated by the presence of 100 microM CoCl2 suggesting the requirement of a metal ion for complete activity. The results support the hypothesis that in many tissues AChE may act as a neuropeptide processing enzyme.
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PMID:Serum acetylcholinesterase possesses trypsin-like and carboxypeptidase B-like activity. 322 17

The effect on enkephalin degradation of the four highly potent organophosphorus anticholinesterases, soman, sarin, tabun and DFP was studied in synaptosomal fractions of rat brain striata. None of the agents effected any of the enkephalin degrading enzymes, the puromycin sensitive aminopeptidase, the p-hydroxymercurybenzoate (p-HMB) sensitive dipeptidyl aminopeptidase or the phosphoramidon sensitive enkephalinase. Furthermore, no peptidase function of acetylcholinesterase was found, when Leu-enkephalin was used as substrate at low concentrations (27 nM). Supporting the in vitro data, no difference was obtained in the striatal levels of Met- and Leu-enkephalin between rats receiving a high single dose of soman and controls. The results show that the analgesic effect of anticholinesterases are more likely due to mechanisms other than inhibition of enkephalin degradation.
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PMID:Organophosphorus anticholinesterases do not mediate analgesia through inhibition of enkephalin degradation. 351 93

Teratocarcinoma cells have been used as a model to study differentiation and development in vertebrates. Treatment with retinoic acid (RA) and dibutyryl cyclic AMP can in some embryonal carcinoma (EC) cell lines lead to neural differentiation, as judged by neurofilament expression and by the induction of enzymes involved in cholinergic transmission. Short-term culture of F9 line cells with RA and dibutyryl cyclic AMP results in a biochemically demonstrable rise in acetylcholinesterase (AChE) activity. We now report that long-term culture of F9 cells with RA and dibutyryl cyclic AMP induces neurofilament expression, demonstrated by immunofluorescence with specific antibodies. Furthermore, if nerve growth factor (NGF) is also added, the developing neurone-like cells exhibit immunoreactivity to tyrosine hydroxylase, a rate-limiting enzyme of catecholamine synthesis specific for adrenergic neurones. Immunoreactivity for Leu-enkephalin-like peptides is also induced. These results suggest that F9 cells can differentiate into cells with adrenergic characteristics.
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PMID:Nerve growth factor induces adrenergic neuronal differentiation in F9 teratocarcinoma cells. 613 54

The neurochemical anatomy of the human nucleus accumbens was studied by comparing the distributional patterns of [3H]DAMGE (mu opioid receptor), [3H]bremazocine (kappa opioid receptor), [3H]SCH-23390 (D1-like dopamine receptor), [3H]7-OH-DPAT (D3 dopamine receptor) binding, preproenkephalin mRNA and acetylcholinesterase activity in sections of post mortem human striatum. Our results demonstrate the presence of at least two neurochemically distinct divisions within the human nucleus accumbens, which may be homologous to the 'shell' and 'core' divisions of the nucleus as found in the rat.
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PMID:Evidence for two neurochemical divisions in the human nucleus accumbens. 770 1

Purified human serum butyrylcholinesterase, which exhibits cholinesterase, aryl acylamidase, and peptidase activities, was cross-reacted with two different monoclonal antibodies raised against human serum butyrylcholinesterase. All three activities were immunoprecipitable at different dilutions of the two monoclonal antibodies. At the highest concentration of the antibodies used, nearly 100% of all three activities were precipitated, and could be recovered to 90-95% in the immunoprecipitate. The peptidase activity exhibited by the purified butyrylcholinesterase was further characterized using both Phe-Leu and Leu-enkephalin as substrates. The pH optimum of the peptidase was in the range of 7.5-9.5 and the divalent cations Co2+, Mn2+, and Zn2+ stimulated its activity. EDTA and other metal complexing agents inhibited its activity. Thiol agents and -SH group modifiers had no effect. The serine protease inhibitors, diisopropylfluorophosphate and phenyl methyl sulfonyl fluoride, did not inhibit. When histidine residues in the enzyme were modified by diethylpyrocarbonate, the peptidase activity was not affected, but the stimulatory effect of Co2+, Mn2+, and Zn2+ disappeared, suggesting the involvement of histidine residues in metal ion binding. These general characteristics of the peptidase activity were also exhibited by a 50 kD fragment obtained by limited alpha-chymotrypsin digestion of purified butyrylcholinesterase. Under all assay conditions, the peptidase released the two amino acids, leucine and phenylalanine, from the carboxy terminus of Leu-enkephalin as verified by paper chromatography and HPLC analysis. The results suggested that the peptidase behaved like a serine, cysteine, thiol-independent metallopeptidase.
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PMID:The peptidase activity of human serum butyrylcholinesterase: studies using monoclonal antibodies and characterization of the peptidase. 842 27