Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

The extraocular muscles of the carp Carassius contain two types of muscle fibre. Large white fibres have ribbon-shaped peripheral myofibrils and triads located at the Z line. Small red fibres, rich in mitochondria, have polygonal-shaped myofibrils and triads at the A-I junction. Silver- and cholinesterase-stained preparations show that the large fibres are innervated by axons which spiral around them and exhibit intense cholinesterase activity over long distances. Axons supplying small muscle fibres run across bundles of fibres, making one contact with each fibre. By electron microscopy the nerve endings on each fibre type appear identical, both having a smooth post-junctional muscle membrane. The differences in structure and innervation pattern of the two fibre types are discussed in relation to their possible functional roles.
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PMID:Structure and innervation of extraocular muscles of Carassius. 118 53

Recent studies suggest that the nature of events leading to the formation, maintenance, and elimination of synapses may be regulated by cascade-type, locally expressed proteases and protease inhibitors acting on adhesive extracellular matrix components. We have identified a molecule in conditioned medium of murine skeletal muscle cells that in molecular weight, target protease inhibition, heparin-binding and cross-reactivity with authenic antisera is similar to the human serine proteinase inhibitor, protease nexin I. Protease nexin I is a 43-50 kDa glycoprotein of the serpin superfamily (arg-serpin class). Purified anti-protease nexin I antibody (anti-47 kDa) stains adult mouse skeletal muscle in discrete foci that precisely superimpose on synaptic neuromuscular junctions. Protease nexin I appears in patches on surfaces of cultured mouse skeletal myotubes, but not on myoblasts. These patches co-localize with acetylcholine receptor clusters and acetylcholinesterase staining during cellular maturation in culture. Evidence that protease nexin I is a synaptic, extracellular antigen is particularly intriguing since it has been shown to be identical, in structure and activity, with a factor released by glial cells, called glia-derived nexin that stimulates mouse neuroblastoma cell neurite outgrowth and inhibits granule cell migration. Protease nexin I inhibits both tumor cell and myoblast plasminogen activator-mediated destruction of extracellular matrix. Thus, such observations as presented in this report provide further evidence for involvement of cascade proteolytic systems, and their post-translational regulation by specific serpins, in the remodeling that occurs in synapse formation and elimination.
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PMID:Plasminogen activators and inhibitors in the neuromuscular system: III. The serpin protease nexin I is synthesized by muscle and localized at neuromuscular synapses. 203 25

The effect of eight doses of 10,000, 20,000 and 30,000 UI of vitamin D2 administered every other day to three groups of rats, on the activities of some enzymes in the animals' liver was evaluated. In general terms, findings revealed a decrease in the activities of glucose-6-phosphatase, phosphorylase and arginase. Likewise, an increase of the activities of maltase and of glutamic oxaloacetic and glutamic pyruvic transaminases was observed. Furthermore, the activities of cholinesterase and alpha-amylase also varied depending on the vitamin D2 doses administered.
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PMID:[Effect of hypervitaminosis D on the activity of various enzymes in the rat liver]. 282 Mar 34

Acetylcholinesterase (EC 3.1.1.7) has been shown to possess an intrinsic peptidase activity. [Chubb et al. (1983), Neuroscience 10, 1369-1383]. To examine this activity further, the breakdown of a model hexapeptide (leu-trp-met-arg-phe-ala) LWMRFA was studied. Affinity-purified eel acetylcholinesterase rapidly cleaved the hexapeptide in a trypsin-like manner to produce two peptides (LWMR and FA). Acetylcholinesterase more slowly cleaved the C-terminal alanine residue from the peptide to yield LWMRF. Although the enzyme showed preference for cleaving the hexapeptide at its C-terminal, it was also able to cleave the N-terminal leucine residue form the tryptic product LWMR. Hydrolysis of the peptide at the tryptic site (arg4-phe5) was strongly inhibited by the trypsin inhibitor diisopropylfluorophosphate. Cleavage of the C-terminal alanine was only poorly inhibited by diisopropylfluorophosphate, but more strongly inhibited by metal-ion chelating agents, and it was increased in the presence of Zn2+ and Co2+. The pH optimum for cleavage at the tryptic site was 6, while that for the carboxypeptidase site was 8-9. These results show that acetylcholinesterase can hydrolyse peptides like a trypsin-like endopeptidase and a Zn2+- or Co2+-dependent exopeptidase, and they suggest that these two peptidase activities are associated with two separate active sites on the acetylcholinesterase molecule. As both peptidase activities eluted with acetylcholinesterase from a TSK 4000SW column when it was chromatographed by high-performance liquid chromatography, it is unlikely that the presence of either peptidase activity could be attributable to a contaminant in the acetylcholinesterase preparation. We suggest that acetylcholinesterase may be involved in the breakdown of bioactive peptides or their precursors in neuroendocrine cells.
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PMID:Acetylcholinesterase exhibits trypsin-like and metalloexopeptidase-like activity in cleaving a model peptide. 330 51

In this study, the effect of sixteen different enzymes on serum C1 and its subcomponents was investigated. The sixteen enzymes could be divided into three groups. First, enzymes which activate native C1: trypsin (optimal concentration 2.4 x 10(-4) mM); alpha-chymotrypsin (2.3 x 10(3) mM); thrombin (1.0 x 10(-5) mM); plasmin (1.9 x 10(-5) mM); elastase (5.8 x 10(-5) mM); pronase (3.0 x 10(-6) mM). All these enzymes are serine esterase and activate native serum C1 bound to EAC4 at the given concentration within 10 min at 30 degrees C. Furthermore, native C1 inhibited by a pentosanpolysulfoester, Sp54, is unable to undergo the internal activation but can be externally activated by the serine esterases. Second, enzymes which do not activate native C1 but result in a dose and time-dependent loss of C1 activity: collagenase; pepsin; carboxypeptidase B. Third, enzymes which have no effect on C1 and C1: Lysozyme; neuraminidase; beta-galactosidase; L-amino acid oxidase; arginase; streptokinase, and acetylcholinesterase.
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PMID:Activation of the first component of complement, C1: comparison of the effect of sixteen different enzymes on serum C1. 619 90

In the sheep medulla oblongata, on the induction of polarity by the applied voltage gradient of direct current along the length, the enzymes such as acetylcholinesterase and glutamate dehydrogenase showed anodal transport while the enzyme arginase showed cathodal transport indicating the possession of negative and positive charge densities on the enzymes. These studies indicated that the glutamate bound metabolism, one towards ammonia formation and the other towards the energy production and neural transmission, have opposed electro-characteristics. The acetylcholinesterase system had anodal characteristics coupled to the glutamate dehydrogenase patterns. The existence of two charge based compartmentation is envisaged in the neural tissue.
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PMID:A biphasic compartmentation of neuro-transmission associated metabolic patterns during electro-induced axoplasmic transport in sheep medulla oblongata. 619 98

Glycosyl-phosphatidylinositol-specific phospholipase D (GPI-PLD) is an amphiphilic protein which, in serum, is associated with high-density lipoproteins (HDL). It is shown that the major component of the HDL fraction, apolipoprotein A-I (apo A-I), is responsible for this association. In the absence of apo A-I, purified GPI-PLD occurred as virtually inactive aggregates which became disaggregated by apo A-I. The enzyme/apo A-I complex efficiently hydrolyzed the solubilized GPI-anchored substrate, acetylcholinesterase. Triton X-100 was also able to dissociate aggregated GPI-PLD, however, it strongly inhibited enzyme activity at detergent concentrations above the critical micellar concentration.
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PMID:Glycosyl-phosphatidylinositol-specific phospholipase D. Interaction with and stimulation by apolipoprotein A-I. 833 9

Inorganic sulfites are chemical compounds with antioxidative, antibacterial and antimycotic properties diffusely employed in agro-food and pharmaceutical industries. In spite of their continuous use there still are many questions regarding their safety, and their possible influence in several nutrients and enzymatic systems, as according to reports in the literature cited. In this study it is determined the effect of increasing doses of sodium bisulphite, 10 to 50 mg/kg/day, injected intramuscularly during seven days on the activity of the following serum enzymes: phosphohexoseisomerase (PHI), gamma-glutamyltranspeptidase (gamma-GT), cholinesterase (CHE), arginase, acid maltase (AM), alkaline phosphatase (AIP), lactic dehydrogenase (LDH), transaminases (GOT and GPT) and 5'-nucleotidase (5'-N) on male Wistar rats (treated groups). The results indicate that in rats treated with sodium bisulphite there is a significant increase (p < 0.05) in the activity of PHI, gamma-GT, arginase, AIP, GOT, GPT and 5'-N as well as an equally significant decrease (p < 0.05) in the activity of LDH, AM and CHE; these variations are proportional to the doses of the compound applied. These findings indicate there is cellular damage to rat liver, kidney or others organs as a result of bisulphite injected or by its metabolic derivatives. It is suggested that measurements of serum levels of LDH, AM and CHE are particularly helpful in the clinical assessment of pathologies caused by sulfites in allergology.
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PMID:[Changes in serum enzymes in rats treated with sodium bisulfite]. 1146 Jul 97

In the present work the effect of intramuscular administration of 30.000, 50.000 and 100.000 IU of vitamin A palmitate daily for seven days, respectively, on the liver enzyme activity in 45 white male Wistar rats, aged 12 weeks and weighing 180-200 g, have been studied. The group control was integrated by 15 healthy rats with similar characteristics (strain, gender, age and weight) to treated animals. Food and water consumption and body weights were recorded at the end of the experimental period. Rats were observed for clinical signs of toxicity. At the end of the study, rats were sacrificed under ether anesthesia. Liver samples were taken for the determination of enzyme activity. Administration of excess of vitamin A produced a significant (p < 0.05) increase in the content of liver vitamin A, determined diverse and variable clinical signs (such as, anorexia, loss of body weight, alopecia, conjunctivitis, external and internal hemorrhages, skin abnormalities and death) and increased (p < 0.05) the activity of the following enzymes: alanine aminotransferase, aspartate aminotransferase, acid maltase (acid alpha-1,4-glucosidase), acid proteases, lactate dehydrogenase and alkaline phosphatase while glucose-6-phosphatase, glycogen phosphorylase, alpha-amylase, cholinesterase and arginase decreased (p < 0.05) as compared with untreated controls. These changes depend on the doses given of vitamin A. In conclusion, our results provide evidence that short-term administration of high doses of vitamin A determined diverse and variable clinical signs and produces a marked alteration of activity of liver enzymes.
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PMID:[Clinical and biochemical alterations in rats treated with high doses of vitamin A]. 1827

This study examined the effects of oral administration of an enzymatic protein hydrolysate from green microalga Chlorella vulgaris (Cv-PH) on the nutritional recovery of malnourished Balb/c mice after a 3-day fasting period. Mice were refed with commercial diet supplemented or not supplemented with Cv-PH (500 mg/kg) for 8 days. Regardless of the diet used during refeeding, animal body weights and serum protein concentrations did not differ between groups. Mice given Cv-PH had a significant increase in hemoglobin concentrations. Most serum amino acid levels were similar in the control and Cv-PH animals. Starved mice refed with Cv-PH showed normal liver functions, as judged by liver weight, protein concentration, and the enzymatic activities of cholinesterase and arginase. Cv-PH increased DNA, protein content, and gut-mucosal weight. In addition, brush-border oligosaccharidase activities were also higher in the Cv-PH group. These findings suggest that Chlorella protein hydrolysate can be used to develop specific formulations suitable for pharmacologic nutrition.
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PMID:Oral administration of an enzymatic protein hydrolysate from the green microalga Chlorella vulgaris enhances the nutritional recovery of malnourished mice. 2166 89


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