Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.1.8 (cholinesterase)
 12,691 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have determined partial N-terminal sequences of acetylcholinesterase (AChE) catalytic subunits from Torpedo marmorata electric organs and from bovine caudate nucleus. We obtain identical sequences (23 amino acids) for the soluble ('low-salt-soluble' or LSS fraction) and particulate ('detergent-soluble', or DS fraction) amphiphilic dimers (G2 form) and for the asymmetric, collagen-tailed forms ('high-salt-soluble', or HSS fraction, A12 + A8 forms). There are two amino acid differences, at position 3 (Asp/His) and 20 (Ile/Val), with the sequences obtained for T. californica by MacPhee-Quigley et al. [(1985) J. Biol. Chem. 260, 12185-12189] for the soluble G2 form and the lytic G4 form which is derived from asymmetric AChE. The bovine sequence (12 amino acids) presents an identity of 4 amino acids (Glu-Leu-Leu-Val) with that of Torpedo, at positions 5-8 (Torpedo) and 7-10 (bovine). There is also a clear homology with the sequence of human butyrylcholinesterase [(1986) Lockridge et al. J. Biol. Chem., in press] indicating that these enzymes probably derive from a common ancestor.
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PMID:Identical N-terminal peptide sequences of asymmetric forms and of low-salt-soluble and detergent-soluble amphiphilic dimers of Torpedo acetylcholinesterase. Comparison with bovine acetylcholinesterase. 379 44

A new antiaggregating chemical, alpha-(p-(fluoren-9-ylidenemethyl)phenyl)-2-piperidineethanol (RMI 10,393), designated FYPE, was found to be an effective inhibitor of platelet aggregation induced by adenosine diphosphate (ADP), thrombin, collagen, or epinephrine. Effects of the antiaggregant on platelets were concentration dependent. Aggregation was prevented by low concentrations of FYPE that produced in the platelet only minor ultrastructural changes consisting of loss of microtubules and of discoid shape. Low levels of FYPE that prevented platelet aggregation had no effect on platelet ATPase activities but did alter clot retraction, the thrombin-induced shift in electrophoretic mobility and platelet cholinesterase activity. Market decrease in ADP release and increase in adenyl cyclase activity were produced by low levels of FYPE. This study provides a model for evaluation of platelet antiaggregating compounds in vitro.
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PMID:Effect of a new antiaggregating chemical on the structure and function of the human platelet. 425 15

Acetylcholinesterase (EC 3.1.1.7.; AChE) and butyrylcholinesterase (EC 3.1.1.8.; BuChE) from chicken muscle exist as sets of structurally homologous forms with very similar properties. The collagenase sensitivity and aggregation properties of the 'heavy' forms of both enzymes indicate that they possess a collagen-like tail, and their stepwise dissociation by trypsin confirms that they correspond to triple (A12) and double (A8) collagen-tailed tetramers. In addition to this dissociating effect, trypsin digests an important fraction of the catalytic units of AChE, in a progressive manner, removing as much as 30% of the enzyme's mass, without inactivation of the tetramers and of the tailed molecules. The trypsin-modified AChE forms closely resemble the corresponding mammalian AChE forms in their hydrodynamic properties. It is not known whether the trypsin-digestible peptides, which do not appear to be involved in the ionic or hydrophobic interactions of the enzymes, are a fragment of the catalytic subunit or whether they constitute distinct polypeptides.
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PMID:The quaternary structure of chicken acetylcholinesterase and butyrylcholinesterase; effect of collagenase and trypsin. 625 92

Molecular forms of acetylcholinesterase and pseudocholinesterase were analyzed directly in the micro-dissected individual endplates of a slow-tonic chicken muscle. The major form in the endplate is the L2(6.5 S) form, while the collagen-tailed H2c (20 S) form, normally considered to be the synaptic form, is a very minor component, in contrast to its predominance at the chicken fast-twitch fibre endplate. The same is true for pseudocholinesterase at these endplates. Outside the tonic fibre endplates the same forms occur as at the endplates, but at a very much lower concentration. The enzyme at the tonic fibre endplate cannot be attached to the basal lamina by a collagen tail, but appears to have a hydrophobic attachment. Acetylcholinesterase is functional at tonic fibre endplates, but the absence of the collagen-tailed form may account for the lower efficiency of the enzymic removal of acetylcholine there.
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PMID:Molecular forms of acetylcholinesterase in synaptic and extrasynaptic regions of avian tonic muscle. 673 21

Purified cultures of neurons and non-neuronal (glial) cells were prepared from the cerebral hemispheres of 10-day chick embryos by a method previously used for embryonic chick sympathetic ganglia 16. This technique separates these cell types on the basis of both: (1) differences in the adhesiveness of neurons and non-neuronal cells to a collagen substrate; and (2) the capacity of neurons to form homotypic aggregates. Purity of the cerebral non-neuronal cultures was determined to be greater than or equal to 99.5% by microscopic examination, while that of the cerebral neuronal cultures was only 92%. Modification of the technique by periodic redissociation of the neuronal aggregates during cell separation increased the purity of the neuronal cultures to greater than or equal to 97% as determined both by microscopic examination and by measurement of levels of butyrylcholinesterase, an enzyme present in the non-neuronal cells. Highly purified cultures of neurons were also prepared from the optic lobes of 10-day chick embryos (greater than or equal to 98%), but attempts to obtain non-neuronal cultures of reasonable density from this tissue were unsuccessful. In addition, highly purified non-neuronal cultures (greater than or equal to 99.5%) were prepared from the dorsal root ganglia of 12-day chick embryos, but cultures enriched with dorsal root neurons could only be partially purified (82%). Specific activity of butyrylcholinesterase in cerebral non-neuronal cells was found to vary inversely with the density of non-neuronal cells.
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PMID:Preparation and partial characterization of highly purified primary cultures of neurons and non-neuronal (glial) cells from embryonic chick cerebral hemispheres and several other regions of the nervous system. 707 61

The structure of the myenteric plexus in the lower esophageal, pyloric and ileo-caecal sphincters of cats is studied in semi-thin sections through impregnation and demonstration of cholinesterase. The plexus ganglia are shown to be well formed structures, with varied sizes and shapes, in the collagen between the muscle layers of the sphincters. Impregnation reveals clearly in them Dogiel's neurones of 1st and 2nd type. The neurones and the nerve bundles of the plexus manifest intensive cholinesterase activity. The morphological data obtained are discussed in view of some functional specificities of the sphincter regions.
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PMID:Structure of the myenteric plexus in the sphincters of cat gastro-intestinal tract. IV. Light-microscopic characteristics. 743 17

We obtained a cDNA clone encoding one type of catalytic subunit of acetylcholinesterase (AChE) from rat brain (T subunit). The coding sequence shows a high frequency of (G+C) at the third position of the codons (66%), as already noted for several AChEs, in contrast with mammalian butyrylcholinesterase. The predicted primary sequence of rat AChE presents only 11 amino acid differences, including one in the signal peptide, from that of the mouse T subunit. In particular, four alanines in the mouse sequence are replaced by serine or threonine. In northern blots, a rat AChE probe indicates the presence of major 3.2- and 2.4-kb mRNAs, expressed in the CNS as well as in some peripheral tissues, including muscle and spleen. In vivo, we found that the proportions of G1, G2, and G4 forms are highly variable in different brain areas. We did not observe any glycolipid-anchored G2 form, which would be derived from an H subunit. We expressed the cloned rat AChE in COS cells: The transfected cells produce principally an amphiphilic G1a form, together with amphiphilic G2a and G4a forms, and a nonamphiphilic G4na form. The amphiphilic G1a and G2a forms correspond to type II forms, which are predominant in muscle and brain of higher vertebrates. The cells also release G4na, G2a, and G1a in the culture medium. These experiments show that all the forms observed in the CNS in vivo may be obtained from the T subunit. By co-transfecting COS cells with the rat T subunit and the Torpedo collagenic subunit, we obtained chimeric collagen-tailed forms. This cross-species complementarity demonstrates that the interaction domains of the catalytic and structural subunits are highly conserved during evolution.
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PMID:Cloning and expression of a rat acetylcholinesterase subunit: generation of multiple molecular forms and complementarity with a Torpedo collagenic subunit. 841 55

In order to elucidate the clinical significance of serum hyaluronan in chronic viral hepatitis, serum hyaluronan concentrations were measured using a sandwich enzyme binding assay in 115 patients with chronic viral hepatitis. These findings were examined in relation to the results of laboratory liver tests, levels of serum markers for fibrosis and liver histological findings. Serum hyaluronan levels increased with the progress of liver disease, particularly in liver cirrhosis. There were no significant differences in serum hyaluronan levels among the cirrhotic patients according to Child's grade. Multivariate analysis showed that the significant independent predictors of serum hyaluronan were serum aspartate aminotransferase (P = 0.020), serum alanine aminotransferase (P = 0.008), serum cholinesterase (P < 0.001), particularly serum type IV collagen 7S domain (P < 0.0001), and the histological degree of liver fibrosis (P < 0.0001). These findings suggest that elevated serum hyaluronan levels are closely related to the severity of liver fibrosis. We assessed the predictive value of serum hyaluronan in differentiating cirrhosis from chronic hepatitis, constructing receiver operating curves; we found that serum hyaluronan was a better test for diagnosing cirrhosis than serum type IV collagen 7S domain and laboratory liver tests.
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PMID:Clinical significance of serum hyaluronan in patients with chronic viral liver disease. 874 18

The collagen-tailed or asymmetric forms (A) represent a major component of acetylcholinesterase (AChE) in the neuromuscular junction of higher vertebrates. They are hetero-oligomeric molecules, in which tetramers of catalytic subunits of type T (AChET) are attached to the subunits of a triple-stranded collagen "tail." We report the cloning of a rat AChE-associated collagen subunit, Q. We show that collagen tails are encoded by a single gene, COLQ. The ColQ subunits form homotrimers and readily form collagen-tailed AChE, when coexpressed with rat AChET. We found that the same ColQ subunits are incorporated, in vivo, in asymmetric forms of both AChE and butyrylcholinesterase. A splice variant from the COLQ gene encodes a proline- rich AChE attachment domain without the collagen domain but does not represent the membrane anchor of the brain tetramer. The COLQ gene is expressed in cholinergic tissues, brain, muscle, and heart, and also in noncholinergic tissues such as lung and testis.
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PMID:The mammalian gene of acetylcholinesterase-associated collagen. 927 46

Chronic liver disease is often accompanied by hypoxaemia. We investigated the clinical factors that were related to the arterial oxygen tension (PaO2) in 40 women, all non-smokers with chronic liver disease. They were positive for hepatitis C virus (HCV) antibody and had no evidence of cardiopulmonary disease. Arterial blood was collected from patients at rest (> 15 min) for analysis of blood gases. We determined the correlation between blood gas tension and the clinical variables, i.e. the presence or absence of skin manifestations such as cutaneous spider nevi and palmar erythema, the presence or absence of splenomegaly, vital capacity, forced expiratory volume in one second, V25/body height, serum alanine aminotransferase (AST), serum asparate aminotransferase (ALT), serum cholinesterase, serum gamma-globulin/total protein, excretion of indocyanine green at 15 min (15-min retention rate, ICG level), blood level of ammonia, blood level of endotoxin, plasma level of glucagon and the serum level of type IV collagen-7S. The mean level of PaO2 was 78 +/- 11 (range: 43-95) torr. The mean alveolar-arterial oxygen tension gradient (A-aDO2) was 19 +/- 13 (range: 2-60) torr. Multiple regression analysis used PaO2 and A-aDO2 as objective variables, and the clinical findings as explanatory variables. The explanatory variables that were significantly correlated with blood gas values were ICG level, blood level of endotoxin and presence of skin manifestations. The ICG level showed a high correlation with blood gas values; the ICG level increased, the PaO2 decreased (r = -0.69), while the A-aDO2 showed a high positive correlation (r = +0.78, P < 0.001). Findings suggest that a reduction in hepatic blood flow and hepatocellular function interfere with the inactivation of vasoactive substances such as endotoxin by the liver, leading to the development of skin manifestations, the dilatation of intrapulmonary capillaries and the induction of hypoxaemia.
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PMID:Clinical factors that affect blood gases in non-smoking women with chronic liver disease. 951 26


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