Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.1.5 (neuropathy target esterase)
 1,070 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The development of a biotinylated substance P (SP) analog for use as a receptor probe is reported. The lysine in position 3 of SP was substituted by arginine and an amino terminal extension (NTE-SP) was added consisting of Lys-Tyr-Gly-Gly-Gly-Gly-Gly-Gly. Biotinylation of the N-terminal lysine was performed. The biotinylated peptide was purified by high performance liquid chromatography and characterized by mass spectral analysis. Binding studies using human IM-9 lymphoblasts with the biotinylated SP analog (biotin-NTE[Arg3]SP) and native SP yielded dissociation curves which were identical. In addition, the biotinylated SP analog retained functional activity similar to that of native SP in altering intracellular calcium concentration of Fura-2 loaded isolated rabbit colonic myocytes. Applicability of the SP receptor probe was demonstrated by using the streptavidin-peroxidase detection system to identify SP receptors on human IM-9 lymphoblasts. In conclusion, a biotinylated SP analog has been developed which retains the functional characteristics of the native peptide and is a useful and versatile probe for receptor studies.
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PMID:Development of a biotinylated analog of substance P for use as a receptor probe. 170 27

The nucleotide sequence of the pldB gene of Escherichia coli K-12, which codes for lysophospholipase L2 located in the inner membrane, was determined. The deduced amino acid sequence of lysophospholipase L2 contains 340 amino acid residues, resulting in a protein with a molecular weight of 38,934. It is characterized by a high content of arginine residues (36 out of 340 residues). The amino acid sequence near the NH2-terminus of the protein is composed of a large number of polar or charged amino acid residues, suggesting that this region cannot be a signal peptide. The hydropathy profile of the deduced amino acid sequence of lysophospholipase L2 was studied. Most of the region was rather hydrophilic, and there was no stretch of hydrophobic amino acid region, such as might be predicted to traverse the lipid bilayer. These results are consistent with the experimental observation that lysophospholipase L2 is extracted by salt solution from the membrane fraction, and it may be classified as a peripheral membrane protein. Computer analysis showed that there is no homology in amino acid sequences between lysophospholipase L2 and other extracellular phospholipases, as well as detergent-resistant phospholipase A, which is another membrane-bound phospholipase in E. coli and whose DNA sequence was determined (Homma, H., Kobayashi, T., Chiba, N., Karasawa, K., Mizushima, H., Kudo, I., Inoue, K., Ideka, H., Sekiguchi, M., & Nojima, S. (1984) J. Biochem. 96, 1655-1664). This is the first report of the primary structure of a lysophospholipase.
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PMID:Nucleotide sequence of the pldB gene and characteristics of deduced amino acid sequence of lysophospholipase L2 in Escherichia coli. 390 45

Oxidized low-density lipoprotein (ox-LDL) plays an important role in the development of atherosclerosis and potentially influences the endothelial regulation of vasomotor tone. We have recently shown that lysophosphatidylcholine (LPC), a lysophospholipid contained in ox-LDL, has various pathophysiological effects. We further examined the role of LPC in the ox-LDL-induced vasoactivity in isolated pig coronary arteries. Copper-induced ox-LDL but not native LDL (n-LDL) elicited endothelium-dependent contraction during plateau contraction evoked by prostaglandin F2 alpha. Lipid extracted from ox-LDL (ox-LDL-lipid) also induced vasocontraction, but lipid of n-LDL (n-LDL-lipid) did not influence tone. When LPC was depleted from ox-LDL (i.e., defatted albumin- or phospholipase B-treated ox-LDL), vasocontraction was significantly attenuated. Synthetic palmitoyl LPC also induced endothelium-dependent vasocontraction, mimicking the response elicited by ox-LDL, but phosphatidylcholine, which exists in n-LDL and is converted to LPC during oxidative modification of LDL, did not influence the tone. Contraction to either ox-LDL or LPC was significantly attenuated by NG-monomethyl-L-arginine but not by indomethacin or superoxide dismutase. Forty minutes of incubation of coronary rings with either ox-LDL or LPC significantly attenuated endothelium-dependent vasorelaxation to thrombin without affecting vasorelaxation to endothelium-independent vasodilator nitroglycerin. In conclusion, LPC contained in lipid fraction of ox-LDL caused endothelium-dependent contraction and inhibited endothelium-dependent relaxation in isolated pig coronary arteries. The vasocontraction might be at least in part caused by LPC-mediated inhibition of endothelium-derived nitric oxide release.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:LPC in oxidized LDL elicits vasocontraction and inhibits endothelium- dependent relaxation. 781 Jul 42

Cytosolic phospholipase A2 (cPLA2) hydrolyzes the sn-2-acyl ester bond of phospholipids and shows a preference for arachidonic acid-containing substrates. We found previously that Ser-228 is essential for enzyme activity and is likely to function as a nucleophile in the catalytic center of the enzyme (Sharp, J. D., White, D. L., Chiou, X. G., Goodson, T., Gamboa, G. C., McClure, D., Burgett, S., Hoskins, J., Skatrud, P. L., Sportsman, J. R., Becker, G. W., Kang, L. H., Roberts, E. F., and Kramer, R. M.(1991) J. Biol. Chem. 266, 14850-14853). cPLA2 contains a catalytic aspartic acid motif common to the subtilisin family of serine proteases. Substitution within this motif of Ala for Asp-549 completely inactivated the enzyme, and substitutions with either glutamic acid or asparagine reduced activity 2000- and 300-fold, respectively. Additionally, using mutants with cysteine replaced by alanine, we found that Cys-331 is responsible for the enzyme's sensitivity to N-ethylmaleimide. Surprisingly, substituting alanine for any of the 19 histidines did not produce inactive enzyme, demonstrating that a classical serine-histidine-aspartate mechanism does not operate in this hydrolase. We found that substituting alanine or histidine for Arg-200 did produce inactive enzyme, while substituting lysine reduced activity 200-fold. Results obtained with the lysine mutant (R200K) and a coumarin ester substrate suggest no specific interaction between Arg-200 and the phosphoryl group of the phospholipid substrate. Arg-200, Ser-228, and Asp-549 are conserved in cPLA2 from six species and also in four nonmammalian phospholipase B enzymes. Our results, supported by circular dichroism, provide evidence that Asp-549 and Arg-200 are critical to the enzyme's function and suggest that the cPLA2 catalytic center is novel.
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PMID:Identification of essential residues for the catalytic function of 85-kDa cytosolic phospholipase A2. Probing the role of histidine, aspartic acid, cysteine, and arginine. 870 2

Neuropathy target esterase (NTE) is a phospholipase/lysophospholipase associated with organophosphorus (OP) compound-induced delayed neurotoxicity (OPIDN). Distal degeneration of motor axons occurs in both OPIDN and the hereditary spastic paraplegias (HSPs). Recently, mutations within the esterase domain of NTE were identified in patients with a novel type of HSP (SPG39) designated NTE-related motor neuron disease (NTE-MND). Two of these mutations, arginine 890 to histidine (R890H) and methionine 1012 to valine (M1012V), were created in human recombinant NTE catalytic domain (NEST) to measure possible changes in catalytic properties. These mutated enzymes had decreased specific activities for hydrolysis of the artificial substrate, phenyl valerate. In addition, the M1012V mutant exhibited a reduced bimolecular rate constant of inhibition (k(i)) for all three inhibitors tested: mipafox, diisopropylphosphorofluoridate, and chlorpyrifos oxon. Finally, while both mutated enzymes inhibited by OP compounds exhibited altered time-dependent loss of their ability to be reactivated by nucleophiles (aging), more pronounced effects were seen with the M1012V mutant. Taken together, the results from specific activity, inhibition, and aging experiments suggest that the mutations found in association with NTE-MND have functional correlates in altered enzymological properties of NTE.
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PMID:Constructs of human neuropathy target esterase catalytic domain containing mutations related to motor neuron disease have altered enzymatic properties. 2038 9

Since the phospholipase B (PLB) was reported as a deacylase of both lecithin and lysolecithin yielding fatty acids and glycerophosphocholine (GPC), there was a question as to whether it is a single enzyme or a mixture of a phospholipase A2 (PLA2) and a lysophospholipase (LPL). We purified the PLB in Penicillium notatum and showed that it catalyzed deacylation of sn-1 and sn-2 fatty acids of 1,2-diacylphospholipids and also sn-1 or sn-2 fatty acids of 1- or 2-monoacylphospholipids (lysophospholipids). Further, it also has a monoacyllipase activity. The purified PLB is a glycoprotein with m.w. of 91,300. The sugar moiety is M9 only and the protein moiety consists of 603 amino acids. PLB, different from PLA2, shows other enzymatic activities, such as transacylase, lipase and acylesterase. PLB activity is influenced by various substances, e.g. detergents, deoxycholate, diethylether, Fe(3+), and endogenous protease. Therefore, PLB might have broader roles than PLA2 in vivo. The database shows an extensive sequence similarity between P. notatum PLB and fungal PLB, cPLA2 and patatin, suggesting a homologous relationship. The catalytic triad of cPLA2, Ser, Asp and Arg, is also present in P. notatum PLB. Other related PLBs, PLB/Lipases are discussed.
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PMID:Reminiscence of phospholipase B in Penicillium notatum. 2574 64

Plesiomonas shigelloides is a Gram-negative rod-shaped bacterium which has been isolated from humans, animals and the environment. It has been associated with diarrhoeal disease in humans and various epizootic diseases in animals. In this study P. shigelloides strains were isolated from the faecal material of a captive Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis; YFP) living in semi-natural conditions in China. Plesiomonas shigelloides strain EE2 was subjected to whole genome sequencing. The draft genome was then compared to the genome sequences of ten other P. shigelloides isolates using the Pathosystems Resource Integration Center pipeline. In addition to several virulence factors which have been previously reported, we are proposing new candidate virulence factors such as a repeats-in-toxin protein, lysophospholipase, a twin-arginine translocation system and the type VI secretion effector Phospholipase A1.
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PMID:Putative virulence factors of Plesiomonas shigelloides. 3137 45