関: phosphoric triester hydrolase

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2017/07/02 15:53:37」(JST)

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Aryldialkylphosphatase (EC 3.1.8.1) (also known as organophosphorus hydrolase, phosphotriesterase, and paraoxon hydrolase) is an enzyme that hydrolyse organophosphates:

an aryl dialkyl phosphate + H₂O

\rightleftharpoons

dialkyl phosphate + an aryl alcohol

Thus, the two substrates of this enzyme are aryldialkylphosphate and H₂O, whereas its two products are dialkylphosphate and aryl alcohol.

Organophosphate is the general name for esters of phosphoric acid and is one of the organophosphorus compounds. They can be found as part of insecticides, herbicides, and nerve gases, amongst others. Some less-toxic organophosphates can be used as solvents, plasticizers, and EP additives.

Function

Bacteria such as Pseudomonas diminuta harbor a plasmid that carries the gene for aryldialkylphosphatase (EC 3.1.8.1). This enzyme has attracted interest because of its potential use in the detoxification of chemical waste and warfare agents and its ability to degrade agricultural pesticides such as parathion. It acts specifically on synthetic organophosphate triesters and phosphorofluoridates. It does not seem to have a natural occurring substrate and may thus have optimally evolved for utilizing paraoxon.

Structure

Aryldialkylphosphatase belongs to a family^[1]^[2] of enzymes that possess a binuclear zinc metal centre at their active site. The two zinc ions are coordinated by six different residues, six of which being histidines.

References

^ Scanlan TS, Reid RC (1995). "Evolution in action". Chem. Biol. 2 (2): 71–75. PMID 9383406. doi:10.1016/1074-5521(95)90278-3.
^ Fletterick RJ, Buchbinder JL, Stephenson RC, Dresser MJ, Pitera JW, Scanlan TS (1998). "Biochemical characterization and crystallographic structure of an Escherichia coli protein from the phosphotriesterase gene family". Biochemistry. 37 (15): 5096–5106. PMID 9548740. doi:10.1021/bi971707+.

English Journal

Persistent organic pollutants distribution in lipoprotein fractions in relation to cardiovascular disease and cancer.

Ljunggren SA1, Helmfrid I2, Salihovic S3, van Bavel B4, Wingren G5, Lindahl M6, Karlsson H7.Author information 1Department of Clinical and Experimental Medicine, Linköping University, SE-58185 Linköping, Sweden. Electronic address: stefan.ljunggren@liu.se.2Occupational and Environmental Medicine, County Council of Östergötland, Linköping University, SE-58185 Linköping, Sweden. Electronic address: ingela.helmfrid@lio.se.3Man-Technology-Environment (MTM) Research Centre, Örebro University, SE-70182 Örebro, Sweden. Electronic address: samira.salihovic@oru.se.4Man-Technology-Environment (MTM) Research Centre, Örebro University, SE-70182 Örebro, Sweden. Electronic address: bert.vanbavel@oru.se.5Department of Clinical and Experimental Medicine, Linköping University, SE-58185 Linköping, Sweden. Electronic address: gun.wingren@liu.se.6Department of Clinical and Experimental Medicine, Linköping University, SE-58185 Linköping, Sweden. Electronic address: mats.lindahl@liu.se.7Occupational and Environmental Medicine, County Council of Östergötland, Linköping University, SE-58185 Linköping, Sweden. Electronic address: helen.m.karlsson@liu.se.AbstractPersistent organic pollutants (POPs) are lipophilic environmental toxins that have been associated with cardiovascular disease (CVD) and cancer. The aim of this study was to investigate the concentrations of POPs in human high and low/very low-density lipoproteins (HDL and LDL/VLDL) and the possible association with CVD and cancer occurrence in individuals living in a contaminated area. Lipoproteins from 28 individuals (7 healthy controls, 8 subjects with cancer, 13 subjects with CVD) were isolated and the fraction-specific concentration of 20 different POPs was analyzed by high resolution gas chromatography/high resolution mass spectrometry. The activity of Paraoxonase 1 (PON1), an anti-oxidant in HDL, was determined in plasma of these 28 subjects and additional 50 subjects from the same area excluding diseases other than cancer or CVD. Fourteen polychlorinated biphenyls (PCBs) and three organochlorine pesticides were detected, and especially highly chlorinated PCBs were enriched in lipoproteins. Significantly higher concentrations of POPs were found among individuals with CVD or cancer compared to controls. Principal component analyses showed that POP concentrations in HDL were more associated with CVD, while POP concentrations in LDL/VLDL were more associated with cancer. PON1 activity was negatively correlated to sumPCB and a co-variation between decreased arylesterase-activity, increased PCB concentrations and CVD was found. This study shows that POPs are present in lipoproteins and were more abundant in individuals with CVD or cancer compared to healthy controls. The results also indicate that PCB exposure is accompanied by reduced PON1 activity that could impair the HDL function to protect against oxidation.
Environment international.Environ Int.2014 Apr;65:93-9. doi: 10.1016/j.envint.2013.12.017. Epub 2014 Jan 25.
Persistent organic pollutants (POPs) are lipophilic environmental toxins that have been associated with cardiovascular disease (CVD) and cancer. The aim of this study was to investigate the concentrations of POPs in human high and low/very low-density lipoproteins (HDL and LDL/VLDL) and the possible
PMID 24472825

In vitro toxicokinetic studies of cyclosarin: Molecular mechanisms of elimination.

Reiter G1, Müller S2, Koller M2, Thiermann H2, Worek F2.Author information 1Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstrasse 11, 80937 Munich, Germany. Electronic address: georgreiter@bundeswehr.org.2Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstrasse 11, 80937 Munich, Germany.AbstractThe toxicokinetics of in vitro elimination of highly toxic cyclosarin (GF) in biological systems revealed striking stereoselective differences in the range of 0.01μM to 1mM GF. While weak concentration dependency was detected for elimination of the toxic (-)-enantiomer indicating catalytic processes, elimination of less toxic (+)-GF followed unusual kinetics with relatively high concentration dependency. Fast initial GF binding in human heparinised plasma increased only at lower initial GF concentrations while (+)-GF binding strongly increased with decreasing GF concentration. In displacement experiments it was shown for the first time that GF binding on plasma components in rats and mice plasma was reversible. Investigations with human plasma require further methodical improvement. GF elimination by diisopropylfluorophosphatase (DFPase) wildtype as phosphotriesterase (PTE) model showed some similarities compared to human heparinised plasma. Impact of human serum albumin is negligible. When comparing kinetics of GF elimination with metabolite formation (fluoride and cyclohexyl methyl phosphonic acid, CHMPA), marked differences were detected. From the results a model was postulated illustrating possible steps of molecular mechanisms of GF interaction with plasma proteins including high affine fast initial binding followed by formation of metastable phosphonylated plasma proteins with subsequent hydrolysis and release of metabolites.
Toxicology letters.Toxicol Lett.2014 Mar 16;227(1):1-11. doi: 10.1016/j.toxlet.2014.03.003. [Epub ahead of print]
The toxicokinetics of in vitro elimination of highly toxic cyclosarin (GF) in biological systems revealed striking stereoselective differences in the range of 0.01μM to 1mM GF. While weak concentration dependency was detected for elimination of the toxic (-)-enantiomer indicating catalytic processe
PMID 24641973

Construction of genetically engineered bacteria that degrades organophosphorus pesticide residues and can be easily detected by the fluorescence.

Li Q, Wang P, Chen R, Li W, Wu YJ.AbstractOrganophosphorus compounds (OPs) are widely used in agriculture and industry and there is increased concern about their toxicological effects in the environment. Bioremediation can offer an efficient and cost-effective option for the removal of OPs. Herein, we describe the construction of a genetically engineered microorganism (GEM) that can degrade OPs and be directly detected and monitored in the environment using an enhanced green fluorescent protein (EGFP) fusion strategy. The coding regions of EGFP, a reporter protein that can fluoresce by itself, and organophosphorus hydrolase (OPH), which has a broad substrate specificity and is able to hydrolyse a number of organophosphorus pesticides, were cloned into the expression vector pET-28b. The fusion protein of EGFP-OPH was expressed in E. coli BL21 (DE3) and the protein expression reached the highest level at 11 h after isopropyl beta-D-thiogalactopyranoside induction. The fluorescence of the GEM was detected by fluorescence spectrophotometry and microscopy, and its ability to degrade OPs was determined by OPH activity assay. Those GEM that express the fusion protein (EGFP and OPH) exhibited strong fluorescence intensity and also potent hydrolase activity, which could be used to degrade organophosphorus pesticide residues in the environment and can also be directly monitored by fluorescence.
Environmental technology.Environ Technol.2014 Mar-Apr;35(5-8):556-61.
Organophosphorus compounds (OPs) are widely used in agriculture and industry and there is increased concern about their toxicological effects in the environment. Bioremediation can offer an efficient and cost-effective option for the removal of OPs. Herein, we describe the construction of a genetica
PMID 24645434

Japanese Journal

3P-116 Sphingobium sp. TCM1株におけるホスホトリエステラーゼの発現制御機構の解析(環境浄化,修復,保全技術,一般講演)

日本生物工学会大会講演要旨集 65, 217, 2013
NAID 110009738063

2Jp04 Sphingobium sp. TCM1株tris(2-chloroethyl)phosphate分解酵素の機能解析(環境浄化・修復・保全技術,一般講演)

日本生物工学会大会講演要旨集平成21年度, 142, 2009
NAID 110007500711

2Jp03 Sphingomonas sp. TDK1株tris(1,3-dichloro-2-propyl)phosphate分解酵素の諸特性解析(環境浄化・修復・保全技術,一般講演)

日本生物工学会大会講演要旨集平成21年度, 142, 2009
NAID 110007500710

「phosphoric triester hydrolase」

Phosphotriesterase family
	Structure of organophosphorus hydrolase
Identifiers
Symbol	PTE
Pfam	PF02126
InterPro	IPR001559
PROSITE	PDOC01026
SCOP	1dpm
SUPERFAMILY	1dpm
Available protein structures:
Pfam	structures
PDB	RCSB PDB; PDBe; PDBj
PDBsum	structure summary

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PubMed	articles
NCBI	proteins

aryldialkylphosphatase
Identifiers
EC number	3.1.8.1
CAS number	117698-12-1
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / EGO
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PubMed	articles
NCBI	proteins

　　[★]

リン酸三エステル加水分解酵素、リン酸三エステルヒドロラーゼ

関: phosphotriesterase

「ホスホトリエステラーゼ」

　　[★]

英: phosphotriesterase
関: リン酸三エステル加水分解酵素

[PUB00000987-1] Scanlan TS, Reid RC (1995). "Evolution in action". Chem. Biol. 2 (2): 71–75. PMID 9383406. doi:10.1016/1074-5521(95)90278-3.

[PUB00000454-2] Fletterick RJ, Buchbinder JL, Stephenson RC, Dresser MJ, Pitera JW, Scanlan TS (1998). "Biochemical characterization and crystallographic structure of an Escherichia coli protein from the phosphotriesterase gene family". Biochemistry. 37 (15): 5096–5106. PMID 9548740. doi:10.1021/bi971707+.

v t e Enzymes
Activity	Active site Binding site Catalytic triad Oxyanion hole Enzyme promiscuity Catalytically perfect enzyme Coenzyme Cofactor Enzyme catalysis
Regulation	Allosteric regulation Cooperativity Enzyme inhibitor
Classification	EC number Enzyme superfamily Enzyme family List of enzymes
Kinetics	Enzyme kinetics Eadie–Hofstee diagram Hanes–Woolf plot Lineweaver–Burk plot Michaelis–Menten kinetics
Types	EC1 Oxidoreductases (list) EC2 Transferases (list) EC3 Hydrolases (list) EC4 Lyases (list) EC5 Isomerases (list) EC6 Ligases (list)

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phosphotriesterase

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