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)

Normal human red cells incubated with saline extracts of tea develop paroxysmal nocturnal hemoglobinuria-like defects as demonstrated by positive acid and sucrose hemolysis tests. All of a variety of tea preparations tested provoked a sensitivity to complement-dependent hemolysis and, with one exception, a moderate decrease in red cell acetylcholinesterase activity. Complement-dependent hemolysis in teaincubated red cells was inhibited by antisera to C3 and C3 activator, but not by antisera to C4. This suggests that incubation with tea may alter the red cell membrane in a way that specifically potentiates the lytic effects of the alternate pathway of complement, but not the classic pathway. Leupeptin, a protease inhibitor, also prevented complement-dependent hemolysis of red cells incubated with tea. Although the clinical consequences of these observations are unknown, the study was initiated following a report of a young male who had developed an acute limited intravascular hemolytic episode following ingestion of large quantities of a herbal tea.
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PMID:Production paroxysmal nocturnal hemoglobinuria-like red blood cells by tea. 59 68

Postsnyaptic membranes in homogenates of the electric tissue of Narcine were identified by labelling nicotinic acetylcholine receptors in the membranes with radioactive alpha-bungarotoxin. Various media and centrifugation conditions were examined in an attempt to obtain highly purified postsynaptic membranes. The main criterion for purification was approach towards the specific activity of the pure receptor protein, 9--10 nmol toxin-sites/mg protein. Isolation of tissue microsomes with Tris buffer, EDTA and the protease inhibitor phenylmethylsulfonylfluoride (PMSF), conditions which preserve the receptor molecules optimally, yielded about 50% of the tissue toxin-sites, 5% of the protein, 4% of the ATPase and less than 2% of the acetylcholinesterase (AChE). Further separation of vesiculated membranes in continuous density gradients of sucrose showed that the major contaminants of postsynaptic membrane vesicles were damaged mitochondria and tubular vesicles of dorsal electroplaque membranes rich in ATPase. Mitochondria were effectively removed from homogenates by 'differential' centrifugation, and ATPase-rich vesicles could be largely removed by causing their agglutination with calcium ions, or by controlled proteolysis in the absence of PMSF. Partially purified postsynaptic membranes were obtained having about 7 nmol toxin-sites/mg membrane protein. Further purification appears possible by affinity techniques.
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PMID:Postsynaptic membranes in the electric tissue of Narcine: III. Isolation and characterization. 61 3

We report here the possible involvement of a new protease in neurite initiation by PC12h cells. Addition of a leupeptin analogue (Ac-Leu-Leu-Nle-al, ALLNal) to PC12h cells on culture plates coated with collagen type I caused de novo neurite outgrowth. Other protease inhibitors (Ac-Leu-Leu-Met-al, leupeptin, E64c, E64d, soybean trypsin inhibitor, hirudin, aprotinin, diisofluorophosphate, 6-aminocapric acid, and pepstatin A) could not mimic this neurite-initiating action. ALLNal induced the initiation of one or two long neurites from the cell body, and increased the cellular level of acetylcholinesterase to an extent similar to nerve growth factor (NGF). However, ALLNal-induced neuritogenesis is different from that induced by NGF, in which many neurites are induced from a single cell body. In addition, in contrast to neurons induced by NGF, which survive for a long time, ALLNal-induced differentiation was transient, and after 48 h percentage of cells bearing neurites started to decrease. After about 120 h exposure to ALLNal, neurites had mostly disappeared and the acetylcholinesterase activity level was not as great as that produced by NGF. These results provide evidence that ALLNal and NGF elicit neurite initiation by different mechanisms, and suggest the existence of a regulatory system of neuronal differentiation through specific protease-protease inhibitor interaction.
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PMID:The neurite-initiating effect of a tripeptide aldehyde protease inhibitor on PC12h cells. 256 Jul 77

The currently available radioimmunoassays of trypsin measure total immunoreactive trypsin (EC 3.1.1.7), which includes both trypsinogen and alpha 1-protease inhibitor-bound trypsin. Hitherto, the only way to differentiate these two forms of trypsin has been to fractionate them on a gel-filtration column. We describe here a solid-phase immunoenzymometric assay that rapidly measures the amount of cationic trypsin bound to alpha 1-protease inhibitor in the plasma of rats with experimental pancreatitis. The assay specifically measures this complex within the range from 0.2 to 5.0 ng without interference by high concentrations of free alpha 1-protease inhibitor. The high correlation (r = 0.985) of the values obtained by size fractionation and by this assay demonstrates the accuracy of the assay, which is the first single-tube method for determining this form of activated cationic trypsin in plasma.
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PMID:Immunoenzymometric determination of trypsin/alpha 1-protease inhibitor complex in plasma of rats with experimental pancreatitis. 352 80

A single direct injection of a local anesthetic, 0.5% bupivacaine hydrochloride (BPVC) (Marcaine), into rat soleus and extensor digitorum longus (EDL) muscles produced massive fiber necrosis with extensive phagocytosis followed by rapid regeneration, predominantly in the soleus. Since the sarcoplasmic reticulum (SR) was functionally disturbed by BPVC administration as confirmed by an in vitro study, the sarcolemmal lysis seen in the early phase of degeneration was not assumed to simply result from direct damage to the plasma membrane caused by BPVC. The extracellular fluid containing a high concentration of calcium (Ca) ions then permeated into the sarcoplasm through the defective membrane resulting in hyper-contracted myofibrils. Selective damage to the Z-line, an early sign of muscle degeneration, was shown by electron microscopy and SDS gel electrophoresis (preferential loss of alpha-actinin). Administration of leupeptin, a thiol protease inhibitor, proved to be ineffective in inhibiting the necrotic process, because the BPVC induced muscle fiber breakdown was probably too acute and fulminant to demonstrate the inhibitory effect upon the degenerative process. Well preserved satellite cells, peripheral nerves, and acetylcholinesterase activity, and the absence of fibrous tissue proliferation in this system may be responsible for the extremely rapid regeneration with complete muscle fiber type differentiation. Since the sequence of fiber breakdown induced by BPVC administration was similar to that of progressive muscular dystrophy, this chemical will be one of the most useful tools for studying the pathophysiology of fiber necrosis and regeneration in diseased muscle.
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PMID:Pathophysiology of muscle fiber necrosis induced by bupivacaine hydrochloride (Marcaine). 661 29

Multiple molecular forms of acetylcholinesterase (AChE EC 3.1.1.7) from fast and slow muscle of rat were examined by velocity sedimentation. The fast extensor digitorum longus muscle (EDL) hydrolyzed acetylcholine at a rate of 110 mumol/g wet weight/hr and possessed three molecular forms with apparent sedimentation coefficients of 4S, 10S, and 16S which contribute about 50, 35, and 15% of the AChE activity. The slow soleus muscle hydrolyzed acetylcholine at a rate of 55 mumol/g wet weight/hr and has a 4S, 10S, 12S, and 16S form which contribute 22, 18, 34, and 26% of AChE activity, respectively. A single band of AChE activity was observed when a 1M NaCl extract with CsCl (0.38 g/ml) was centrifuged to equilibrium. Peak AChE activity from EDL and SOL extracts were found at 1.29 g/ml. Resedimentation of peak activity from CsCl gradients resulted in all molecular forms previously found in both muscles. Addition of a protease inhibitor phenylmethylsulfonyl chloride did not change the pattern of distribution. The 4S form of both muscles was extracted with low ionic strength buffer while the 10S, 12S, and 16S forms required high ionic strength and detergent for efficient solubilization. All molecular forms of both muscles have an apparent Km of 2 x 10(-4) M, showed substrate inhibition, and were inhibited by BW284C51, a specific inhibitor of AChE. The difference between these muscles in regards to their AChE activity, as well as in the proportional distribution of molecular forms, may be correlated with sites of localization and differences in the contractile activity of these muscles.
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PMID:Characterization of acetylcholinesterase molecular forms in slow and fast muscle of rat. 662 81

1. Experiments were designed to study the effects of ageing on muscarine and NK2 receptor mechanisms in the three different regions of rabbit airway. 2. The pD2 value of acetylcholine changed with age in three different regions while that of carbamylcholine, which is resistant to acetylcholinesterase, did not. 3. The pD2 values of neurokinin A and the activity of protease, a degradative enzyme, changed with age. However, by the pretreatment with phosphoramidon, a protease inhibitor, the regional difference and age related change of the pD2 value of neurokinin A disappeared. 4. In conclusion, the observations about age related changes and regional differences of pD2 value of acetylcholine and neurokinin A were due to the difference of their degradative enzyme activities.
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PMID:Effects of ageing on regional differences in the contractile responses to acetylcholine and neurokinin A in rabbit airway. 795 29

Tegumental extracts from adult worms of Schistosoma mansoni contain an inhibitory activity to the S. mansoni 28-kDa serine protease and to pancreatic elastase. By using biotinylated elastase and streptavidin-agarose, the postulated protease inhibitor has been isolated from the crude worm extract in a single step. Monospecific rabbit antibodies raised against the protease inhibitor have immunoprecipitated a 56-kDa [35S]Met-labeled serine protease inhibitor which was designated Smpi56 (S. mansoni protease inhibitor, 56 kDa). Smpi56 binds tightly to and inhibits the 28-kDa protease of S. mansoni and pancreatic and neutrophil elastase but not papain, pepsin, thrombin, trypsin, chymotrypsin, proteinase K, urokinase and acetylcholinesterase. The biological function of Smpi56 is still not known, but in view of its elastase inhibitory activity it may be speculated that the parasite is employing Smpi56 to protect itself from activated neutrophils. Smpi56 may also potentially protect the parasite from its endogenous 28-kDa protease.
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PMID:Schistosoma mansoni: isolation and characterization of Smpi56, a novel serine protease inhibitor. 811 69

Neurofibrillary tangles and amyloid plaques express acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activity in Alzheimer's disease. We had found that traditional AChE inhibitors such as BW284C51, tacrine and physostigmine were more potent inhibitors of the AChE in normal axons and cell bodies than of the AChE in plaques and tangles. We now report that the reverse pattern is seen with indolamines, carboxypeptidase inhibitor, and the nonspecific protease inhibitor bacitracin. These substances are more potent inhibitors of the cholinesterases in plaques and tangles than of those in normal axons and cell bodies. These results show that the enzymatic properties of plaque and tangle-associated cholinesterases diverge from those of normal axons and cell bodies. The selective susceptibility to bacitracin and carboxypeptidase inhibitor indicates that the catalytic sites of plaque and tangle-bound cholinesterases are more closely associated with peptidase or protease-like properties than the catalytic sites of cholinesterases in normal neurons and axons. This shift in enzymatic affinity may lead to the abnormal protein processing which is thought to play a major role in the pathogenesis of AD. The availability of pharmacological and dietary means for altering brain indolamines raises novel therapeutic possibilities for inhibiting the abnormal cholinesterase activity associated with Alzheimer's disease.
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PMID:Protease inhibitors and indolamines selectively inhibit cholinesterases in the histopathologic structures of Alzheimer's disease. 823 15

Neurofibrillary tangles and amyloid plaques express acetylcholinesterase and butyrylcholinesterase activity in Alzheimer disease. We previously reported that traditional acetylcholinesterase inhibitors such as BW284C51, tacrine, and physostigmine were more potent inhibitors of the acetylcholinesterase in normal axons and cell bodies than of the acetylcholinesterase in plaques and tangles. We now report that the reverse pattern is seen with indoleamines (such as serotonin and its precursor 5-hydroxytryptophan), carboxypeptidase inhibitor, and the nonspecific protease inhibitor bacitracin. These substances are more potent inhibitors of the cholinesterases in plaques and tangles than of those in normal axons and cell bodies. These results show that the enzymatic properties of plaque and tangle-associated cholinesterases diverge from those of normal axons and cell bodies. The selective susceptibility to bacitracin and carboxypeptidase inhibitor indicates that the catalytic sites of plaque and tangle-bound cholinesterases are more closely associated with peptidase or protease-like properties than the catalytic sites of cholinesterases in normal axons and cell bodies. This shift in enzymatic affinity may lead to the abnormal protein processing that is thought to play a major role in the pathogenesis of Alzheimer disease. The availability of pharmacological and dietary means for altering brain indoleamines raises therapeutic possibilities for inhibiting the abnormal cholinesterase activity associated with Alzheimer disease.
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PMID:Protease inhibitors and indoleamines selectively inhibit cholinesterases in the histopathologic structures of Alzheimer disease. 842 6


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