Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have used a set of overlapping cloned segments defining a 315 kb (X 10(3) base-pairs) region of Drosophila melanogaster chromosomal DNA to map the sequences associated with the polytene band-interbands (chromomeric units) and with the lethal complementation groups contained within this region. The molecular map positions of the 13 +/- 1 chromomeric units from the 87D5-6 to 87E5, 6 region of the third chromosome were determined by in situ hybridization of selected segments to the polytene chromosomes. The length of the largest chromomeric unit within the 315 kb region is approximately 160 kb, while that for the smallest is less than 7 kb and may be as short as 3 kb. By mapping the breakpoints of deletions within the 315 kb region, we have located its 12 lethal complementation groups, which include the genes coding for acetylcholinesterase (Ace) and xanthine dehydrogenase (rosy). Comparison of the two molecular maps indicates a one-to-one topographical correlation between the genetic and chromomeric units.
J Mol Biol 1983 Jul 25
PMID:Molecular mapping of genetic and chromomeric units in Drosophila melanogaster. 622 22

By measuring the permeability across the lipid bilayer in the presence and absence of membrane-bound protein or glycoprotein it should be possible to get an impression concerning their ability to penetrate into the membrane bilayer. Proteins such as phospholipase A2 and acetylcholinesterase markedly increase the permeability in contrast to glycoproteins (ovomucoid and orosomucoid) and cytochrome C. The results may serve as an indication of the type of interaction between lipids and membrane components.
Mol Biol Rep 1982 Apr 16
PMID:Glycoprotein and protein induced changes in liposome permeability. 628 80

The actions of pyridostigmine (Pyr), an anticholinesterase agent, were studied on the acetylcholine (ACh) receptor-ion channel complex and on the electrically excitable membrane of the frog cutaneous pectoris and sartorius muscles and the chronically denervated soleus muscle of the rat. Pyr at concentrations of 0.2-0.4 mM potentiated the indirect evoked muscle twitch and at concentrations greater than or equal to 0.8 mM depressed the indirect twitch with an IC50 of about 2 mM. Twitch depression produced by Pyr was reversed slowly, and after a 60-min wash only 59% of the control muscle twitch had returned. Pyr did not affect either the membrane potential or the muscle action potential. Pyr had several effects at the neuromuscular junction of the frog and rat. It decreased the peak amplitude of the end-plate current (EPC) in a voltage- and concentration-dependent manner. In contrast to diisopropylfluorophosphate, which depresses the EPC amplitude and induces a double exponential decay of the EPC and miniature end-plate current (MEPC), Pyr produced a marked prolongation of the time constants of EPC and MEPC decay while maintaining a single exponential decay. The decrease caused by Pyr of indirect twitch tension, EPC amplitude, and ACh sensitivity indicates mechanisms which limit the number and/or properties of conducting channels. The drug decreased channel conductance and prolonged channel lifetime as revealed by Fourier analysis of ACh-induced end-plate current fluctuations. An altered form of the conducting species induced by Pyr appears to be responsible for either the apparent agonist-induced depolarization or its ability to increase the affinity of ACh for its recognition site. Pyr was also found to inhibit the binding of ACh and alpha-bungarotoxin to receptor-rich membrane from the electric organ of Torpedo nobiliana, and to have a higher affinity for the receptor than for the ion channel binding sites. These actions are distinct from acetylcholinesterase inhibition caused by the agent. Strong evidence suggests that the direct influences of the agent on neuromuscular transmission involve at least three distinct, although possibly interacting, mechanisms: (a) a weak agonist action, (b) the formation of desensitized receptor-complex intermediates, and (c) the alteration of the conductance properties of active channels.
Mol Pharmacol 1984 Jan
PMID:The nature of the interactions of pyridostigmine with the nicotinic acetylcholine receptor-ionic channel complex. I. Agonist, desensitizing, and binding properties. 632 55

A chromosomal walk is described that covers 315 X 10(3) base-pairs of DNA from the 87DE region of the third chromosome of Drosophila melanogaster. The walk includes the DNA for the rosy and Ace loci, which code for xanthine dehydrogenase and acetylcholinesterase, respectively. Several dispersed repetitive elements were encountered in the walk. In every case, their positions in the chromosome differed in different strains, and so they are all presumed to be transposable elements. Several rearrangement breakpoints have been localized within the walk, including the break for In(3R) Cbx+R1 (87E1, 2-89E1, 2). One breakpoint fusion fragment of this inversion was isolated to jump from 87E into the cluster of homeotic genes of the bithorax complex, at 89E1-4.
J Mol Biol 1983 Jul 25
PMID:Chromosomal walking and jumping to isolate DNA from the Ace and rosy loci and the bithorax complex in Drosophila melanogaster. 641 77

An ultrastructural, histochemical, and biochemical study of the electric organ of the South American Torpedinid ray, Discopyge tschudii, was carried out. Fine structural cytochemical localization of acetylcholinesterase (AChE) indicated that most of the esterase was associated with the basal lamina. Electron microscopy indicated no marked differences in the electrocyte ultrastructure between Discopyge and Torpedo californica. Discopyge electric organ possessed three molecular forms, two asymmetric forms (16 S and 13 S) and one globular hydrophobic form (6.5 S). The asymmetric 16 S AChE form was solubilized by heparin, a sulfated glycosaminoglycan, suggesting that heparin-like macromolecules are involved in the binding of the enzyme to the basal lamina. Our results show that cell-free translated AChE peptides, synthesized using Discopyge electric organ poly(A+) RNA, correspond to a main band of 62,000 daltons which probably represents the catalytic subunit of the asymmetric AChE.
Cell Mol Neurobiol 1984 Jun
PMID:The electric organ of Discopyge tschudii: its innervated face and the biology of acetylcholinesterase. 648 42

Separation of the external membranes from freshly converted mechanical schistosomula of Schistosoma mansoni was achieved by osmotic shock under hypertonic conditions, followed by mechanical shearing and ultracentrifugation. Prior to treatment, the schistosomula were surface labeled by introduction of N-DNP-epsilon-aminocaproylphosphatidylethanolamine molecules into their lipid bilayer followed by anti-DNP antibodies and stained with either 125I-protein-A or ferritin labeled secondary anti-DNP antibodies. This label provided a membrane marker by which the purity of the preparation could be assessed at each stage. Fluorescence staining with FITC-conjugated secondary antibodies prior to treatment revealed that the homogeneously stained membrane of the intact schistosomula became swollen and ruptured after the osmotic shock. The isolated membrane pellet was intensely fluorescent. Electron microscopical examination revealed mostly vesicles, some of them with organized multilayer assembly. The vesicles were ferritin labeled, indicating that they originated from the outer surface membrane of the schistosomula. A 100 fold enrichment in the alkaline phosphatase activity and about 300 fold enrichment in acetylcholinesterase activity in the membrane preparations, as compared to the intact schistosomula, was found. The isolated tegument was analyzed by SDS-polyacrylamide gel electrophoresis. The pattern obtained showed three major bands, of molecular weights 69 000, 45 000 and 12 000 alongside with a large number of minor bands. Immunoprecipitation of the isolated 125I-labeled membrane antigens with antisera from chronically infected mice revealed these three major bands together with three other bands of molecular weight 38 000, 23 000 and 16 000.
Mol Biochem Parasitol 1984 Nov
PMID:Isolation and partial characterization of the tegumental outer membrane of schistosomula of Schistosoma mansoni. 652 92

A fluorescent acyldicholine, bis-(choline)N-[4-nitrobenzo-2-oxa-1,3-diazol-7-yl]-iminodiprop ionate (BCNI), was synthesized and its capacity to associate with acetylcholinesterase and the nicotinic acetylcholine receptor examined. The fluorescent bisquaternary diester competitively inhibits acetylcholinesterase with a Ki of 0.46 microM. Binding is accompanied by a large decrease in BCNI fluorescence and a 40% reduction in enzyme tryptophanyl fluorescence due to spectral overlap between BCNI absorption and the fluorescence emission of tryptophanyl residues on the enzyme. BCNI titrations show a stoichiometry of one site per subunit and a dissociation constant of 0.2 microM. BCNI also inhibits the initial rate of alpha-toxin binding to the membrane-associated nicotinic acetylcholine receptor and yields a protection constant (Kp) of 0.26 microM. Prior exposure of BCNI to the receptor increases the affinity of the complex, and after equilibration Kp is found to be 0.11 microM. Fluorescence titrations reveal that BCNI binds with 1:1 stoichiometry to alpha-toxin sites on the receptor with a dissociation constant of 0.22 microM. Agonists and antagonists, but not local anesthetics, compete with BCNI binding. BCNI behaves as a competitive antagonist on receptors from the snake neuromuscular junction and from BC3H-1 cells. The 4-nitrobenzo-2-oxa-1,3-diazole fluorophore in BCNI shows a hypsochromatic shift and an enhancement of quantum yield when bound to the receptor but is quenched when associated with acetylcholinesterase. Thus, despite the similarity in dissociation constants, the fluorophore exists in very different environments when bound to the two proteins.
Mol Pharmacol 1984 Jul
PMID:Interaction of a fluorescent acyldicholine with the nicotinic acetylcholine receptor and acetylcholinesterase. 654 67

The conformation of acetylcholine (Ach) and its muscarinic analogue beta-methyl acetylcholine (beta-MeAch) on an alumina surface was analyzed by inelastic electron tunneling spectroscopy (IETS). This method detects vibrational modes of organic molecules that are active in both Raman (R) and IR spectroscopies. By using previously recorded and interpreted R and IR spectra of Ach and beta-MeAch in solid-state and aqueous solutions we studied the perturbations due to adsorption. The results were used to interpret the interaction of both molecules with the alumina surface, and a comparison to that with receptors or with acetylcholinesterase was attempted. In the case of nonhydrolytic interaction, the positive trimethylammonium groups of both molecules seemed to be attracted by the negative oxygen ions of the surface. There was evidence that the O--C--C--N skeleton of Ach changed its conformation in aqueous solution and adopted the solid-state conformation, which is very similar to that of beta-MeAch. This conformation once established, Ach appeared to interact with the alumina surface in the same way as did beta-MeAch: both tunneling spectra were very similar. There was also evidence that in the acetyl part of both molecules the C=O double bond was broken and that the oxygen atom coordinated with an Al+ cation. The acetyl skeleton did not show important conformational changes for either molecule. In the case of hydrolytic interaction of Ach or beta-MeAch, the products of the hydrolysis, acetate ion and choline--the latter also adsorbed in ionic form--were found on the alumina surface. In both cases the conformation of the lateral groups bonded to the choline and acetyl skeletons was also analyzed.
Mol Pharmacol 1982 Nov
PMID:Inelastic electron tunneling spectroscopic study of interaction of acetylcholine and beta-methyl acetylcholine with alumina surface. 675 17

The inhibition by atropine of cholinesterase from Pseudomonas aeruginosa has been studied in parallel with the membrane bound acetylcholinesterase from rat red cells. Acetylcholinesterase of rat red cells, like other animal cholinesterases, was competitively inhibited while the cholinesterase from Pseudomonas aeruginosa was partially non competitively inhibited by atropine. These results clearly indicated a different behavior of cholinesterase from Pseudomonas aeruginosa in comparison with the enzyme of Pseudomonas fluorescens and other animal cholinesterases.
Mol Cell Biochem 1981 Jan 28
PMID:Acetylcholinesterase from rat red cells and cholinesterase of Pseudomonas aeruginosa: different types of inhibition by atropine. 678 72

Carboxylesterases (EC 3.1.1.1) of chicken brain were investigated by applying kinetic analysis of organophosphorus inhibition. By iterative elimination of exponential inhibition curves and by sequential inhibition experiments using a combination of two organophosphorus inhibitors, 11 different carboxylesterases of chicken brain were characterized with respect to their phenyl valerate-hydrolyzing activity (milliunits per gram of brain) and their inhibition by O,O-diethyl O-4-nitrophenyl phosphate (Paraoxon), O,O-diisopropylphosphorofluoridate, and N,N'-diisopropylphosphorodiamidic fluoride (Mipafox). The bimolecular inhibition rate constants (liters . mole-1 . min-1) were calculated for the 11 enzymes and 3 organophosphorus compounds. The corresponding data for acetylcholinesterase (EC 3.1.1.7) in chicken brain were determined. The importance of inhibition rate constants for the development of acute cholinergic symptoms, delayed neurotoxicity, and atypical organophosphate effects is shown.
Mol Pharmacol 1983 May
PMID:Inhibition of brain carboxylesterases by neurotoxic and nonneurotoxic organophosphorus compounds. 686 14


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