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Marsillach J, Suzuki SM, Richter RJ, McDonald MG, Rademacher PM, MacCoss MJ, Hsieh EJ, Rettie AE, Furlong CE. Human valacyclovir hydrolase/biphenyl hydrolase-like protein is a highly efficient homocysteine thiolactonase. PLoS One 2014; 9:e110054. [PMID: 25333274 PMCID: PMC4198189 DOI: 10.1371/journal.pone.0110054] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 09/08/2014] [Indexed: 11/29/2022] Open
Abstract
Homocysteinylation of lysine residues by homocysteine thiolactone (HCTL), a reactive homocysteine metabolite, results in protein aggregation and malfunction, and is a well-known risk factor for cardiovascular, autoimmune and neurological diseases. Human plasma paraoxonase-1 (PON1) and bleomycin hydrolase (Blmh) have been reported as the physiological HCTL detoxifying enzymes. However, the catalytic efficiency of HCTL hydrolysis by Blmh is low and not saturated at 20 mM HCTL. The catalytic efficiency of PON1 for HCTL hydrolysis is 100-fold lower than that of Blmh. A homocysteine thiolactonase (HCTLase) was purified from human liver and identified by mass spectrometry (MS) as the previously described human biphenyl hydrolase-like protein (BPHL). To further characterize this newly described HCTLase activity, BPHL was expressed in Escherichia coli and purified. The sequence of the recombinant BPHL (rBPHL) and hydrolytic products of the substrates HCTL and valacyclovir were verified by MS. We found that the catalytic efficiency (kcat/Km) of rBPHL for HCTL hydrolysis was 7.7 × 104 M−1s−1, orders of magnitude higher than that of PON1 or Blmh, indicating a more significant physiological role for BPHL in detoxifying HCTL.
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Affiliation(s)
- Judit Marsillach
- Department of Medicine (Division of Medical Genetics), University of Washington, Seattle, Washington, United States
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States
| | - Stephanie M. Suzuki
- Department of Medicine (Division of Medical Genetics), University of Washington, Seattle, Washington, United States
| | - Rebecca J. Richter
- Department of Medicine (Division of Medical Genetics), University of Washington, Seattle, Washington, United States
| | - Matthew G. McDonald
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington, United States
| | - Peter M. Rademacher
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington, United States
| | - Michael J. MacCoss
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States
| | - Edward J. Hsieh
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States
| | - Allan E. Rettie
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington, United States
| | - Clement E. Furlong
- Department of Medicine (Division of Medical Genetics), University of Washington, Seattle, Washington, United States
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States
- * E-mail:
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Kim DS, Crosslin DR, Auer PL, Suzuki SM, Marsillach J, Burt AA, Gordon AS, Meschia JF, Nalls MA, Worrall BB, Longstreth WT, Gottesman RF, Furlong CE, Peters U, Rich SS, Nickerson DA, Jarvik GP. Rare coding variation in paraoxonase-1 is associated with ischemic stroke in the NHLBI Exome Sequencing Project. J Lipid Res 2014; 55:1173-8. [PMID: 24711634 DOI: 10.1194/jlr.p049247] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Indexed: 11/20/2022] Open
Abstract
HDL-associated paraoxonase-1 (PON1) is an enzyme whose activity is associated with cerebrovascular disease. Common PON1 genetic variants have not been consistently associated with cerebrovascular disease. Rare coding variation that likely alters PON1 enzyme function may be more strongly associated with stroke. The National Heart, Lung, and Blood Institute Exome Sequencing Project sequenced the coding regions (exomes) of the genome for heart, lung, and blood-related phenotypes (including ischemic stroke). In this sample of 4,204 unrelated participants, 496 had verified, noncardioembolic ischemic stroke. After filtering, 28 nonsynonymous PON1 variants were identified. Analysis with the sequence kernel association test, adjusted for covariates, identified significant associations between PON1 variants and ischemic stroke (P = 3.01 × 10(-3)). Stratified analyses demonstrated a stronger association of PON1 variants with ischemic stroke in African ancestry (AA) participants (P = 5.03 × 10(-3)). Ethnic differences in the association between PON1 variants with stroke could be due to the effects of PON1Val109Ile (overall P = 7.88 × 10(-3); AA P = 6.52 × 10(-4)), found at higher frequency in AA participants (1.16% vs. 0.02%) and whose protein is less stable than the common allele. In summary, rare genetic variation in PON1 was associated with ischemic stroke, with stronger associations identified in those of AA. Increased focus on PON1 enzyme function and its role in cerebrovascular disease is warranted.
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Affiliation(s)
- Daniel Seung Kim
- Division of Medical Genetics, Department of Medicine University of Washington School of Medicine, Seattle, WA Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA
| | - David R Crosslin
- Division of Medical Genetics, Department of Medicine University of Washington School of Medicine, Seattle, WA Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA
| | - Paul L Auer
- Division of Medical Genetics, Department of Medicine University of Washington School of Medicine, Seattle, WA Zilber School of Public Health, University of Wisconsin-Milwaukee, Milwaukee, WI
| | - Stephanie M Suzuki
- Division of Medical Genetics, Department of Medicine University of Washington School of Medicine, Seattle, WA
| | - Judit Marsillach
- Division of Medical Genetics, Department of Medicine University of Washington School of Medicine, Seattle, WA Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA
| | - Amber A Burt
- Division of Medical Genetics, Department of Medicine University of Washington School of Medicine, Seattle, WA
| | - Adam S Gordon
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA
| | | | - Mike A Nalls
- Laboratory of Neurogenetics, National Institute on Aging, National Institutes of Health, Bethesda, MD
| | - Bradford B Worrall
- Center for Public Health Genomics, University of Virginia, Charlottesville, VA Department of Neurology, University of Virginia, Charlottesville, VA Department of Public Health Sciences, University of Virginia, Charlottesville, VA
| | - W T Longstreth
- Department of Neurology University of Washington, Seattle, WA Department of Epidemiology, University of Washington, Seattle, WA
| | - Rebecca F Gottesman
- Cerebrovascular Division, Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Clement E Furlong
- Division of Medical Genetics, Department of Medicine University of Washington School of Medicine, Seattle, WA Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA
| | - Ulrike Peters
- Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA Department of Epidemiology, University of Washington, Seattle, WA
| | - Stephen S Rich
- Center for Public Health Genomics, University of Virginia, Charlottesville, VA
| | - Deborah A Nickerson
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA
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Baker PE, Cole TB, Cartwright M, Suzuki SM, Thummel KE, Lin YS, Co AL, Rettie AE, Kim JH, Furlong CE. Identifying safer anti-wear triaryl phosphate additives for jet engine lubricants. Chem Biol Interact 2012; 203:257-64. [PMID: 23085349 DOI: 10.1016/j.cbi.2012.10.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 09/22/2012] [Accepted: 10/10/2012] [Indexed: 11/15/2022]
Abstract
Individuals aboard jet aircraft may be exposed to potentially toxic triaryl organophosphate anti-wear lubricant additives (TAPs) that are converted by cytochromes P450 into toxic metabolites. Consequences of exposure could be reduced by using less toxic TAPs. Our goal was to determine whether an in vitro assay for inhibition of butyrylcholinesterase (BChE) by bioactivated TAPs would be predictive of inhibition of serine active-site enzymes in vivo. The in vitro assay involved TAP bioactivation with liver microsomes and NADPH, followed by incubation with human BChE and measurement of BChE activity. Of 19 TAPs tested, tert-butylated isomers produced the least BChE inhibition. To determine the relevance of these results in vivo, mice were exposed to Durad 125 (D125; a commercial mixture of TAP esters) or to TAPs demonstrating low or no BChE inhibition when assayed in vitro. Inhibition of BChE by bioactivated TAPs in vitro correlated well with inhibition of other serine active-site enzymes in vivo, with the exception of brain acetylcholinesterase and neuropathy target esterase (NTE), which were not inhibited by any TAP tested following single exposures. A recombinant catalytic domain of NTE (rNEST) exhibited classical kinetic properties of NTE. The metabolite of tri-(o-cresyl) phosphate (ToCP), 2-(o-cresyl)-4H-1,3,2-benzodioxaphosphoran-2-one (CBDP), inhibited rNEST in vitro, but with an IC(50) value almost 6-times higher than for inhibition of BChE. Physiologically-relevant concentrations of the flavonoid naringenin dramatically reduced D125 bioconversion in vitro. The in vitro assay should provide a valuable tool for prescreening candidate TAP anti-wear additives, identifying safer additives and reducing the number of animals required for in vivo toxicity testing.
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Affiliation(s)
- Paul E Baker
- Department of Medicine-Division of Medical Genetics, University of Washington, Seattle, WA 98195, United States.
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Marsillach J, Richter RJ, Kim JH, Stevens RC, MacCoss MJ, Tomazela D, Suzuki SM, Schopfer LM, Lockridge O, Furlong CE. Biomarkers of organophosphorus (OP) exposures in humans. Neurotoxicology 2011; 32:656-60. [PMID: 21767566 DOI: 10.1016/j.neuro.2011.06.005] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 06/09/2011] [Accepted: 06/09/2011] [Indexed: 11/25/2022]
Abstract
There are ongoing events where aircraft engine lubricant containing tricresyl phosphates (TCPs) contaminates aircraft cabins. Some individuals have experienced tremors or other neurological symptoms that may last for many months following exposures. Mass spectrometric (MS) protocols are being developed to determine the percentage of "biomarker proteins" that are modified by such exposures, specifically on active site serines. Both plasma butyrylcholinesterase (BChE) and red cell acylpeptide hydrolase (APH) are readily inhibited by 2-(ortho-cresyl)-4H-1,3,2-benzodioxaphosphoran-2-one (CBDP) or phenyl saligenin cyclic phosphate (PSP) and have the potential to provide information about the level of exposure of an individual. We have developed immunomagnetic bead-based single-step purification protocols for both BChE and APH and have characterized the active site serine adducts of BChE by MS.
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Affiliation(s)
- Judit Marsillach
- Department of Medicine, Division Medical Genetics, University of Washington, Seattle, WA 98195-7720, United States
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Furlong CE, Suzuki SM, Stevens RC, Marsillach J, Richter RJ, Jarvik GP, Checkoway H, Samii A, Costa LG, Griffith A, Roberts JW, Yearout D, Zabetian CP. Human PON1, a biomarker of risk of disease and exposure. Chem Biol Interact 2010; 187:355-61. [PMID: 20338154 DOI: 10.1016/j.cbi.2010.03.033] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Revised: 03/16/2010] [Accepted: 03/17/2010] [Indexed: 01/04/2023]
Abstract
Human paraoxonase 1 (PON1) is a high-density lipoprotein (HDL)-associated serum enzyme that exhibits a broad substrate specificity. In addition to protecting against exposure to some organophosphorus (OP) pesticides by hydrolyzing their toxic oxon metabolites, PON1 is important in protecting against vascular disease by metabolizing oxidized lipids. Recently, PON1 has also been shown to play a role in inactivating the quorum sensing factor N-(3-oxododecanoyl)-l-homoserine lactone (3OC12-HSL) of Pseudomonas aeruginosa. Native, untagged engineered recombinant human PON1 (rHuPON1) expressed in Escherichia coli and purified by conventional column chromatographic purification is stable, active, and capable of protecting PON1 knockout mice (PON1(-/-)) from exposure to high levels of the OP compound diazoxon. The bacterially derived rHuPON1 can be produced in large quantities and lacks the glycosylation of eukaryotic systems that can produce immunogenic complications when inappropriately glycosylated recombinant proteins are used as therapeutics. Previous studies have shown that the determination of PON1 status, which reveals both PON1(192) functional genotype and serum enzyme activity level, is required for a meaningful evaluation of PON1's role in risk of disease or exposure. We have developed a new two-substrate assay/analysis protocol that provides PON1 status without use of toxic OP substrates, allowing for use of this protocol in non-specialized laboratories. Factors were also determined for inter-converting rates of hydrolysis of different substrates. PON1 status also plays an important role in revealing changes in HDL-associated PON1 activities in male patients with Parkinson disease (PD). Immunolocalization studies of PONs 1, 2 and 3 in nearly all mouse tissues suggest that the functions of PONs 1 and 3 extend beyond the plasma and the HDL particle.
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Affiliation(s)
- C E Furlong
- University of Washington, Department of Medicine (Div. of Medical Genetics), Seattle, WA, United States.
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Kim JH, Stevens RC, MacCoss MJ, Goodlett DR, Scherl A, Richter RJ, Suzuki SM, Furlong CE. Identification and characterization of biomarkers of organophosphorus exposures in humans. Adv Exp Med Biol 2010; 660:61-71. [PMID: 20221871 PMCID: PMC2878371 DOI: 10.1007/978-1-60761-350-3_7] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Over 1 billion pounds of organophosphorus (OP) chemicals are manufactured worldwide each year, including 70 million pounds of pesticides sprayed in the US. Current methods to monitor environmental and occupational exposures to OPs such as chlorpyrifos (CPS) have limitations, including low specificity and sensitivity, and short time windows for detection. Biomarkers for the OP tricresyl phosphate (TCP), which can contaminate bleed air from jet engines and cause an occupational exposure of commercial airline pilots, crewmembers and passengers, have not been identified. The aim of our work has been to identify, purify, and characterize new biomarkers of OP exposure. Butyrylcholinesterase (BChE) inhibition has been a standard for monitoring OP exposure. By identifying and characterizing molecular biomarkers with longer half-lives, we should be able to clinically detect TCP and OP insecticide exposure after longer durations of time than are currently possible. Acylpeptide hydrolase (APH) is a red blood cell (RBC) cytosolic serine proteinase that removes N-acetylated amino acids from peptides and cleaves oxidized proteins. Due to its properties, it is an excellent candidate for a biomarker of exposure. We have been able to purify APH and detect inhibition by both CPS and metabolites of TCP. The 120-day lifetime of the RBC offers a much longer window for detecting exposure. The OP-modified serine conjugate in the active site tryptic peptide has been characterized by mass spectrometry. This research uses functional proteomics and enzyme activities to identify and characterize useful biomarkers of neurotoxic environmental and occupational OP exposures.
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Hawkins VN, Hapuarachchi HC, Rungsihirunrat K, Na-Bangchang K, Maestre A, Sibley CH, Suzuki SM. Assessment of the Origins and Spread of Putative Resistance-Conferring Mutations in Plasmodium vivax Dihydropteroate Synthase. Am J Trop Med Hyg 2009. [DOI: 10.4269/ajtmh.2009.81.348] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Hawkins VN, Suzuki SM, Rungsihirunrat K, Hapuarachchi HC, Maestre A, Na-Bangchang K, Sibley CH. Assessment of the origins and spread of putative resistance-conferring mutations in Plasmodium vivax dihydropteroate synthase. Am J Trop Med Hyg 2009; 81:348-355. [PMID: 19635897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023] Open
Abstract
Infection with Plasmodium vivax is usually treated with chloroquine, but parasites are often exposed inadvertently to sulfadoxine-pyrimethamine. To infer patterns of selection and spread of resistant parasites in natural populations, we determined haplotypes of P. vivax dihydropteroate synthase ( dhps ) alleles that could confer resistance to sulfadoxine. We amplified the P. vivax pyrophosphokinase ( pppk )- dhps region and its flanking intergenic regions from 92 contemporary global isolates. Introns and exons of pppk-dhps were highly polymorphic, as were the flanking intergenic regions. Eighteen haplotypes were associated with wild-type alleles, but several different putatively sulfadoxine-resistant alleles have arisen in areas of intensive sulfadoxine-pyrimethamine use. Even when they encoded changes to the same amino acid, these mutant alleles were associated with multiple different haplotypes. Two main conclusions can be drawn from these data. First, dhps alleles resistant to sulfadoxine have arisen multiple times under drug pressure. Second, there has been convergent evolution of a variety of alleles that could confer resistance to sulfa drugs.
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Affiliation(s)
- Vivian N Hawkins
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195-5065, USA
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Affiliation(s)
- D K Moser
- Department of Medicine, UCLA School of Medicine 90024
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Abstract
Raynaud's syndrome is a common medical problem. Approach to diagnosis must involve a search for underlying causes. Treatment includes avoidance of precipitating factors, biofeedback, and possibly pharmacologic therapy, after careful consideration of risks.
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Affiliation(s)
- S Marcus
- University of California, Los Angeles, UCLA School of Medicine
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