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Xu S, Chen Y, Ma Y, Liu T, Zhao M, Wang Z, Zhao L. Lipidomic Profiling Reveals Disruption of Lipid Metabolism in Valproic Acid-Induced Hepatotoxicity. Front Pharmacol 2019; 10:819. [PMID: 31379584 PMCID: PMC6659130 DOI: 10.3389/fphar.2019.00819] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 06/24/2019] [Indexed: 12/13/2022] Open
Abstract
Valproic acid (VPA) is one of the most widely prescribed antiepileptic drugs, as VPA-induced hepatotoxicity is one of the most severe adverse reaction that can lead to death. The objective of this study was to gain an understanding of dysregulated lipid metabolism in mechanism of hepatotoxicity. Nontargeted lipidomics analysis with liquid chromatography-quadrupole-time-of-flight mass spectrometry (LC-Q-TOF/MS) was performed to explore differential lipids from the patient serum and L02 cells. Lipidomics data interpretation was augmented by gene expression analyses for the key enzymes in lipid metabolism pathways. From patient serum lipidomics, pronouncedly changed lipid species between abnormal liver function (ALF) patients and normal liver function (NLF) patients were identified. Among these lipid species, LPCs, Cers, and SMs were markedly reduced in the ALF group and showed negative relationships with liver injury severity [alanine aminotransferase (ALT) levels], while significantly increased triacylglycerols (TAG) with higher summed carbon numbers demonstrated a positive relationship with ALT levels. Regarding lipidomics in hepatic L02 cells, TAG was markedly elevated after VPA exposure, especially in TAGs with more than 53 summed carbons. Besides, gene expression analysis revealed dysregulated lipid metabolism in VPA-treated L02 cells. Peroxime proliferators-activated receptor (PPARγ) pathway played an important role in VPA-induced lipid disruption through inducing long-chain fatty acid uptake and TAG synthesis, which was also regulated by Akt pathway. Our findings present that VPA-induced lipid metabolism disruption might lead to lipotoxicity in the liver. This approach is expected to be applicable for other drug-induced toxicity assessments.
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Affiliation(s)
- Shansen Xu
- Department of Pharmacy, Shengjing Hospital of China Medical University, Shenyang, China
| | - Yanan Chen
- Department of Pharmacy, Shengjing Hospital of China Medical University, Shenyang, China
| | - Yiyi Ma
- Department of Pharmacy, Shengjing Hospital of China Medical University, Shenyang, China
| | - Ting Liu
- Shanghai AB Sciex Analytical Instrument Trading Co. Ltd., Shanghai, China
| | - Mingming Zhao
- Department of Pharmacy, Shengjing Hospital of China Medical University, Shenyang, China
| | - Zhanyou Wang
- Institute of Health Sciences, Key Laboratory of Medical Cell Biology of Ministry of Education, China Medical University, Shenyang, China
| | - Limei Zhao
- Department of Pharmacy, Shengjing Hospital of China Medical University, Shenyang, China
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2
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Holmes MJ, Southworth T, Watson NG, Povey MJW. Enzyme activity determination using ultrasound. ACTA ACUST UNITED AC 2014. [DOI: 10.1088/1742-6596/498/1/012003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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3
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Eba C, Okano A, Nakano H, Iwasaki Y. A chromogenic substrate for solid-phase detection of phospholipase A₂. Anal Biochem 2014; 447:43-5. [PMID: 24239575 DOI: 10.1016/j.ab.2013.11.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 11/02/2013] [Indexed: 11/25/2022]
Abstract
A method for solid-phase detection of phospholipase A₂ (PLA₂) was developed. The method uses 1-octanoyloxynaphthalene-3-sulfonic acid, which was found to be a good substrate of PLA₂. The substrate is hydrolyzed by PLA₂ into 1-naphthol-3-sulfonic acid, which is spontaneously coupled with coexisting diazonium salt to form a red-purple azo dye. Streptomyces and bovine pancreatic PLA₂ spotted on a nitrocellulose membrane could be detected by this method with considerable sensitivity. In addition, colonies of recombinant Escherichia coli producing bacterial PLA₂ were distinguishable from those producing an inactive mutant PLA₂, facilitating high-throughput screening in directed evolution of the enzyme.
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Affiliation(s)
- Chisato Eba
- Laboratory of Molecular Biotechnology, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Aoi Okano
- Laboratory of Molecular Biotechnology, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Hideo Nakano
- Laboratory of Molecular Biotechnology, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Yugo Iwasaki
- Laboratory of Molecular Biotechnology, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.
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4
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Matsubara T, Tanaka N, Patterson AD, Cho JY, Krausz KW, Gonzalez FJ. Lithocholic acid disrupts phospholipid and sphingolipid homeostasis leading to cholestasis in mice. Hepatology 2011; 53:1282-93. [PMID: 21480330 PMCID: PMC3077083 DOI: 10.1002/hep.24193] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
UNLABELLED Lithocholic acid (LCA) is an endogenous compound associated with hepatic toxicity during cholestasis. LCA exposure in mice resulted in decreased serum lysophosphatidylcholine (LPC) and sphingomyelin levels due to elevated lysophosphatidylcholine acyltransferase (LPCAT) and sphingomyelin phosphodiesterase (SMPD) expression. Global metabolome analysis indicated significant decreases in serum palmitoyl-, stearoyl-, oleoyl-, and linoleoyl-LPC levels after LCA exposure. LCA treatment also resulted in decreased serum sphingomyelin levels and increased hepatic ceramide levels, and induction of LPCAT and SMPD messenger RNAs (mRNAs). Transforming growth factor-β (TGF-β) induced Lpcat2/4 and Smpd3 gene expression in primary hepatocytes and the induction was diminished by pretreatment with the SMAD3 inhibitor SIS3. Furthermore, alteration of the LPCs and Lpcat1/2/4 and Smpd3 expression was attenuated in LCA-treated farnesoid X receptor-null mice that are resistant to LCA-induced intrahepatic cholestasis. CONCLUSION This study revealed that LCA induced disruption of phospholipid/sphingolipid homeostasis through TGF-β signaling and that serum LPC is a biomarker for biliary injury.
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Affiliation(s)
- Tsutomu Matsubara
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Naoki Tanaka
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Andrew D. Patterson
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Joo-Youn Cho
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Kristopher W. Krausz
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Frank J. Gonzalez
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892,Correspondence: Frank J. Gonzalez, Laboratory of Metabolism, National Cancer Institute, Building 37, Room 3106, Bethesda, MD 20892, Tel: 301–496–9067, Fax: 301–496–8419,
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5
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Mosmuller EWJ, Van Heemst JDH, Van Delden CJ, Franssen MCR, Engbersen JFJ. A New Spectrophotometric Method for the Detection of Lipase Activity Using 2,4-Dinitrophenyl Butyrate as a Substrate. ACTA ACUST UNITED AC 2009. [DOI: 10.3109/10242429209014874] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- E. W. J. Mosmuller
- Laboratory of Organic Chemistry, Wageningen Agricultural University Dreijenplein, 8, 6703 HB, Wageningen, The Netherlands
| | - J. D. H. Van Heemst
- Laboratory of Organic Chemistry, Wageningen Agricultural University Dreijenplein, 8, 6703 HB, Wageningen, The Netherlands
| | - C. J. Van Delden
- Laboratory of Organic Chemistry, Wageningen Agricultural University Dreijenplein, 8, 6703 HB, Wageningen, The Netherlands
| | - M. C. R. Franssen
- Laboratory of Organic Chemistry, Wageningen Agricultural University Dreijenplein, 8, 6703 HB, Wageningen, The Netherlands
| | - J. F. J. Engbersen
- Laboratory of Organic Chemistry, Wageningen Agricultural University Dreijenplein, 8, 6703 HB, Wageningen, The Netherlands
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6
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Price JA. A colorimetric assay for measuring phospholipase A2 degradation of phosphatidylcholine at physiological pH. ACTA ACUST UNITED AC 2007; 70:441-4. [PMID: 17169434 DOI: 10.1016/j.jbbm.2006.10.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2006] [Revised: 10/16/2006] [Accepted: 10/24/2006] [Indexed: 10/23/2022]
Abstract
Phospholipase A(2) is an important enzyme in various pathologies. Although fluorescent substrate assays for it have been recently developed, there is a need for an assay with inexpensive commercially available substrates, useful when samples interfered with fluorescent assays, that is nonisotopic, continuous, conducted at physiological pH, and in a 96 well format. A reaction using bromothymol blue was developed that meets all these requirements.
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Affiliation(s)
- Joseph A Price
- Department of Pathology, Oklahoma State University Center for Health Sciences, 1111 W. 17th. St. Tulsa, OK 74107-1898, USA.
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7
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Finn PF, Dice JF. Proteolytic and lipolytic responses to starvation. Nutrition 2006; 22:830-44. [PMID: 16815497 DOI: 10.1016/j.nut.2006.04.008] [Citation(s) in RCA: 223] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2005] [Revised: 03/30/2006] [Accepted: 04/12/2006] [Indexed: 01/20/2023]
Abstract
Mammals survive starvation by activating proteolysis and lipolysis in many different tissues. These responses are triggered, at least in part, by changing hormonal and neural statuses during starvation. Pathways of proteolysis that are activated during starvation are surprisingly diverse, depending on tissue type and duration of starvation. The ubiquitin-proteasome system is primarily responsible for increased skeletal muscle protein breakdown during starvation. However, in most other tissues, lysosomal pathways of proteolysis are stimulated during fasting. Short-term starvation activates macroautophagy, whereas long-term starvation activates chaperone-mediated autophagy. Lipolysis also increases in response to starvation, and the breakdown of triacylglycerols provides free fatty acids to be used as an energy source by skeletal muscle and other tissues. In addition, glycerol released from triacylglycerols can be converted to glucose by hepatic gluconeogenesis. During long-term starvation, oxidation of free fatty acids by the liver leads to the production of ketone bodies that can be used for energy by skeletal muscle and brain. Tissues that cannot use ketone bodies for energy respond to these small molecules by activating chaperone-mediated autophagy. This is one form of interaction between proteolytic and lipolytic responses to starvation.
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Affiliation(s)
- Patrick F Finn
- Department of Molecular and Cellular Physiology, Tufts University School of Medicine, Boston, Massachusetts, USA
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8
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Jiménez-Atiénzar M, Cabanes J, Gandía-Herrero F, Escribano J, García-Carmona F, Pérez-Gilabert M. Determination of the phospholipase activity of patatin by a continuous spectrophotometric assay. Lipids 2003; 38:677-82. [PMID: 12934679 DOI: 10.1007/s11745-003-1114-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Patatin is a family of glycoproteins that accounts for 30-40% of the total soluble protein in potato (Solanum tuberosum L.) tubers. This protein has been reported to serve as a storage protein and also to exhibit lipid phospholipase activity. This paper describes a simple continuous spectrophotometric method for assaying patatin phospholipase activity. The procedure is based on a coupled enzymatic assay using [1,2-dilinoleoyl] PC as the phospholipase substrate and lipoxygenase as the coupling enzyme. In the procedure developed in this work, lipoxygenase oxidizes the linoleic acid released by the phospholipase activity of patatin. This activity can then be followed spectrophotometrically by recording the increase in absorbance at 234 nm that results from the formation of the corresponding hydroperoxide from linoleic acid by the action of lipoxygenase. The optimal assay concentrations of patatin and lipoxygenase were established. Phospholipase activity varied with pH, reaching its optimal value at pH 9.5. Scans of the deoxycholate concentration pointed to an optimal detergent concentration of 3 mM. Phospholipid hydrolysis followed classical Michaelis-Menten kinetics (Vm = 9.8 x 10(-3) micromol/min x microg protein, Km = 7.8 microM, Vm/Km = 1.3 min(-1) x microg protein). This method proved to be specific since there was no activity in the absence of patatin. It also had the advantages of a short analysis time and the use of commercially nonradiolabeled and inexpensive substrates, which are, furthermore, natural substrates of phospholipase.
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Affiliation(s)
- M Jiménez-Atiénzar
- Departamento de Bioquímica y Biología Molecular A, Universidad de Murcia, Espinardo 30071, Murcia, Spain.
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10
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Farias RN, Torres M, Canela R. Spectrophotometric determination of the positional specificity of nonspecific and 1,3-specific lipases. Anal Biochem 1997; 252:186-9. [PMID: 9324958 DOI: 10.1006/abio.1997.2240] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Using commercially available thiosubstrates, such as 2,3-dimercapto-1-propanol tributyrate, the regio-specificities of 1,3-specific and nonspecific lipases was confirmed. The spectrophotometric test is a simple, rapid, and convenient alternative method to those previously reported for the characterization of the positional specificities of new lipases.
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Affiliation(s)
- R N Farias
- Departamento de Bioquímica de la Nutrición, Instituto Superior de Investigaciones Biológicas (CONICET-UNT), San Miguel de Tucumán, Argentina.
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11
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Abstract
Phospholipase A2 (PLA2), an enzyme found in most snake venoms, catalyzes the hydrolysis of phospholipids in biological membranes, and some have presynaptic neurotoxic activity. A synthetic substrate, 4-nitro-3-(octanoyloxy)benzoic acid, was synthesized and purified on a silica gel column using a published method. This substrate was used to develop an endpoint assay which is rapid and requires a minimum of equipment. This aqueous assay system allowed enzyme activity to be examined without the use of radioactive substrates or organic solvents, minimizing waste disposal concerns. Whole venoms, partially purified enzyme isolated from Crotalus mitchelli pyrrhus venom, tissue extracts and commercial preparations were employed as sources of PLA2. Results show that this method is a convenient and specific assay for PLA2 from several sources and is particularly suited for assaying large numbers of fractions generated during purification procedures.
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Affiliation(s)
- M Holzer
- Department of Biological Sciences, University of Northern Colorado, Greeley 80639, USA
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12
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13
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Bhat MK, Mueller-Harvey I, Sumner IG, Goodenough PW. Simplified methods for the synthesis of 2-hexadecanoylthio-1-ethylphosphorylcholine and for the determination of phospholipase A2 activity. BIOCHIMICA ET BIOPHYSICA ACTA 1993; 1166:244-50. [PMID: 8443243 DOI: 10.1016/0005-2760(93)90104-h] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A simple and straight forward method was developed for the synthesis of 2-hexadecanoylthio-1-ethyl phosphorylcholine (HEPC). The new procedure, which used p-toulenesulfonate instead of 2-bromoethyl phosphorylcholine, not only reduced the reaction time but also allowed the reaction to proceed under mild conditions. Using HEPC as a substrate, we have also developed a microplate assay for measuring phospholipase A2 activity which is rapid and will be useful for analyzing a large number of samples in a very short time. The applicability of this assay method for assessing phospholipases A2 from two different sources and determining their kinetic constants is also demonstrated. This method can also be extended for measuring lipases and lysophospholipases using a suitable thioester. Thus, both synthesis and assay methods will be useful in basic and applied research on phospholipases and related enzymes.
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Affiliation(s)
- M K Bhat
- AFRC Institute of Food Research, Department of Protein Engineering, Reading Laboratory, UK
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14
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Freysz L, Farooqui AA, Horrocks LA, Massarelli R, Dreyfus H. Stimulation of mono- and diacylglycerol lipase activities by gangliosides in chicken neuronal cultures. Neurochem Res 1991; 16:1241-4. [PMID: 1815140 DOI: 10.1007/bf00966702] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Chicken neurons in culture display measurable activities of mono- and diacylglycerol lipases. Treatment of chicken neuronal cultures with gangliosides (10(-8)M to 10(-5)M) resulted in a time and dose dependent increase in monoacylglycerol lipase activity. The diacylglycerol lipase showed significant increase in specific activity before that of monoacylglycerol lipase. The increase was observed only up to 24 hours and no differences between diacylglycerol lipase activity of control and ganglioside treated cells were observed after 48 hours. The data indicate that the treatment of neurons with exogenous gangliosides affect the diglyceride metabolism in stimulating not only the enzymes catalyzing their production but also those involved in their catabolism.
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Affiliation(s)
- L Freysz
- Centre de Neurochemie du CNRS, Strasbourg, France
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15
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Kan CC, Bittman R, Hajdu J. Phospholipids containing nitrogen- and sulfur-linked chains: kinetics of cholesterol exchange between vesicles. BIOCHIMICA ET BIOPHYSICA ACTA 1991; 1066:95-101. [PMID: 2065074 DOI: 10.1016/0005-2736(91)90256-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We have examined the kinetics of [14C]cholesterol exchange between unilamellar vesicles formed from the following synthetic glycerophosphatidylcholines: (a) those having acyl (OC(O)R), acylamino (NHC(O)R), carbamoyl (NHC(O)OR), and acylthio (SC(O)R) chains at the sn-2 position, and (b) those having alkyl (OR) and thioalkyl (SR) chains at the sn-1 position. Replacement of the glycerol oxygen atom at the sn-2 position of PC with a NH group did not affect the rate of cholesterol exchange to a significant extent, suggesting that the amide group of sphingomyelin is not primarily responsible for the very slow rate of exchange of cholesterol observed from sphingomyelin vesicles. Replacement of the glycerol oxygen at the sn-2 position of phosphatidylcholine with a sulfur atom caused the rate of spontaneous cholesterol exchange to increase by a factor of 1.6. Substitution of an O-alkyl chain for the acyl chain at the sn-1 position of 2-acylthiophosphatidylcholine or substitution of a thioalkyl chain for the O-alkyl sn-1 chain of 1-alkyl-2-acylaminodeoxyphosphatidylcholine also did not result in a marked difference in cholesterol exchange rate. The data suggest that interactions other than intermolecular hydrogen bonding are involved in determining the rates of intermembrane cholesterol exchange. Significantly, these kinetic studies also lend support to the continued use in model membranes of synthetic sulfur- and nitrogen-substituted phosphatidylcholines, which have been employed to study properties of lipolytic enzymes, since synthetic acylamino- and acylthio-phospholipids form vesicles that give cholesterol exchange rates that closely resemble those found in vesicles prepared with diester-phosphatidylcholines.
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Affiliation(s)
- C C Kan
- Department of Chemistry and Biochemistry, Queens College of The City University of New York, Flushing 11367
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16
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Hostetler KY, Gardner MF, Aldern KA. Assay of phospholipases C and D in presence of other lipid hydrolases. Methods Enzymol 1991; 197:125-34. [PMID: 2051909 DOI: 10.1016/0076-6879(91)97139-p] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The activity of a phospholipase C or phospholipase D may be assessed by measuring the radioactivity or phosphate released into the aqueous phase of a lipid extract. However, in crude enzyme fractions, this type of analysis may not be possible due to formation of water-soluble metabolites by other enzymatic reactions, as demonstrated here with a crude lysosomal enzyme fraction. In such instances, analysis of both water-soluble and lipid-soluble metabolites, at various times of incubation, may still provide clear identification of phospholipases C or D, even when a variety of lipases and other hydrolases are present.
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Abstract
Of the general considerations discussed, the two issues which are most important in choosing an assay are (1) what sensitivity is required to assay a particular enzyme and (2) whether the assay must be continuous. One can narrow the options further by considering substrate availability, enzyme specificity, assay convenience, or the presence of incompatible side reactions. In addition, the specific preference of a particular phospholipase for polar head group, micellar versus vesicular substrates, and anionic versus nonionic detergents may further restrict the options. Of the many assays described in this chapter, several have limited applicability or serious drawbacks and are not commonly employed. The most commonly used phospholipase assays are the radioactive TLC assay and the pH-stat assay. The TLC assay is probably the most accurate, sensitive assay available. These aspects often outweigh the disadvantages of being discontinuous, tedious, and expensive. The radioactive E. coli assay has become popular recently as an alternative to the TLC assay for the purification of the mammalian nonpancreatic phospholipases. The assay is less time consuming and less expensive than the TLC assay, but it is not appropriate when careful kinetics are required. Where less sensitivity is needed, or when a continuous assay is necessary, the pH-stat assay is often employed. With purified enzymes, when free thiol groups are not present, a spectrophotometric thiol assay can be used. This assay is approximately as sensitive as the pH-stat assay but is more convenient and more reproducible, although the substrate is not available commercially. Despite the many assay choices available, the search continues for a convenient, generally applicable assay that is both sensitive and continuous. The spectrophotometric SIBLINKS assay and some of the fluorescent assays show promise of filling this need.
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18
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Farooqui AA, Anderson DK, Flynn C, Bradel E, Means ED, Horrocks LA. Stimulation of mono- and diacylglycerol lipase activities by bradykinin in neural cultures. Biochem Biophys Res Commun 1990; 166:1001-9. [PMID: 2302218 DOI: 10.1016/0006-291x(90)90910-f] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Neural cultures of fetal mouse spinal cord, mouse neuroblastoma (N1E-115) and mixed primary glial cell cultures from neonatal rat brain display measurable activities of mono- and diacylglycerol lipases. Treatment of fetal mouse spinal cord cultures with bradykinin (10 nM) for 1-4 min resulted in a marked increase in specific activities of mono- and diacylglycerol lipases. This is the first direct demonstration that bradykinin can act through the lipase pathway. The increase in activities of lipases was dose and time dependent. The bradykinin response was blocked by [Thi5,8, D-Phe7]bradykinin, a bradykinin B-2 receptor antagonist, indicating that the bradykinin induced stimulation of lipase activities involves bradykinin receptors.
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Affiliation(s)
- A A Farooqui
- Department of Physiological Chemistry, Ohio State University, Columbus 43210
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19
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Bariszlovich M, Meusel D, Tülsner M. [The characterization of microbial lipases. 1. The determination of lipase activity]. DIE NAHRUNG 1990; 34:701-17. [PMID: 2233988 DOI: 10.1002/food.19900340811] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In the selection of an appropriate method for activity determination of lipases existing technical equipment, kind of enzymes, number of samples investigated (e.g. in routine analysis), and expected sensitivity range have to be taken into account. Titrimetric methods and above all copper salt methods with their high detection sensitivity are the most suitable procedures for activity determination of lipases used in laboratories and institutions without equipment for radiochemical analysis.
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Affiliation(s)
- M Bariszlovich
- Wissenschaftsbereich Lebensmittelchemie Humboldt-Universität zu, Berlin, DDR
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20
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Hirashima Y, Jurkowitz-Alexander MS, Farooqui AA, Horrocks LA. Continuous spectrophotometric assay of phospholipase A2 activity hydrolyzing plasmalogens using coupling enzymes. Anal Biochem 1989; 176:180-4. [PMID: 2712287 DOI: 10.1016/0003-2697(89)90290-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We developed a continuous spectrophotometric assay of the phospholipase A2 activity specific for choline plasmalogen using rat liver lysoplasmalogenase and horse liver alcohol dehydrogenase as coupling enzymes and Naja naja venom phospholipase A2 as a source of the phospholipase A2 activity. In these coupling reactions, choline lysoplasmalogen is hydrolyzed by lysoplasmalogenase to glycerophosphocholine and free aldehyde. The free aldehyde is quantitatively converted to alcohol by alcohol dehydrogenase with the oxidation of NADH. The disappearance of NADH is measured spectrophotometrically at 340 nm. The assay is sensitive to about 0.2 nmol aldehyde produced/ml/min and also is rapid, convenient, and continuous.
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Affiliation(s)
- Y Hirashima
- Ohio State University, Department of Physiological Chemistry, Columbus 43210
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21
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Kucera GL, Miller C, Sisson PJ, Wilcox RW, Wiemer Z, Waite M. Hydrolysis of thioester analogs by rat liver phospholipase A1. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)37657-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Abstract
The activities of monoacylglycerol and diacylglycerol lipases were 6 to 8 times higher in plasma membrane and synaptosomal plasma membrane fractions of nucleus basalis from patients with Alzheimer's disease than in those membranes from normal human brains. Membranes from the hippocampus region of Alzheimer-affected brains also showed consistently higher activities of monoacylglycerol and diacylglycerol lipases than those from control brains. These results indicate a stimulation of lipolytic enzymes in nucleus basalis and hippocampus regions in patients with Alzheimer's disease.
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Affiliation(s)
- A A Farooqui
- Department of Physiological Chemistry, Ohio State University, Columbus 43210
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23
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Farooqui AA, Tejwani GA, Mahle CD, Hanissian SH, Taylor WA, Horrocks LA. Mono- and diacylglycerol lipases in spinal cord of lean and obese Zucker rats. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. B, COMPARATIVE BIOCHEMISTRY 1987; 87:341-4. [PMID: 2957145 DOI: 10.1016/0305-0491(87)90149-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
1. Genetically obese Zucker rats (fa/fa) contain 2-3 times higher activities mono- and diacylglycerol lipases in their spinal cords than their lean littermates. 2. When rats were exercised (1 hr daily, 5 days/week) on a treadmill for 6 months, there was a decrease of about 30% (P less than 0.05) in the activities of mono- and diacylglycerol lipases in lean rats but not in obese animals. 3. High activities of lipases in Zucker obese rats may be related to the elevated levels of beta-endorphin present in these animals. 4. The activities of arylsulfatase, beta-N-acetylhexosaminidase and alkaline phosphatase, tested to check the stability of spinal cord extracts, were similar in lean and obese rat spinal cords.
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Quantitation of phospholipase A2 and phospholipase C activity using alkaline phosphatase impregnated liposomes. Microchem J 1986. [DOI: 10.1016/0026-265x(86)90130-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Stead D. Microbial lipases: their characteristics, role in food spoilage and industrial uses. J DAIRY RES 1986; 53:481-505. [PMID: 3531258 DOI: 10.1017/s0022029900025103] [Citation(s) in RCA: 115] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Farooqui AA, Taylor WA, Horrocks LA. Characterization and solubilization of membrane bound diacylglycerol lipases from bovine brain. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1986; 18:991-7. [PMID: 3100358 DOI: 10.1016/0020-711x(86)90244-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Bovine brain contains two diacylglycerol lipases. One is localized in purified microsomes and the other is found in the plasma membrane fraction. The microsomal enzyme is markedly stimulated by the non-ionic detergent, Triton X-100, and Ca2+, whereas the plasma membrane diacylglycerol lipase is strongly inhibited by Triton X-100 and Ca2+ has no effect on its enzymic activity. Both enzymes were solubilized using 0.25% Triton X-100. The solubilized enzymes followed Michaelis-Menten kinetics. The apparent Km values for microsomal and plasma membrane enzymes are 30.5 and 12.0 microM respectively. Both lipases are strongly inhibited by RHC 80267, with Ki values for microsomal and plasma membrane diacylglycerol lipases of 70 and 43 microM, respectively. The retention of microsomal diacylglycerol lipase on a concanavalin A-Sepharose column and its elution by methyl alpha-D-mannoside indicates the glycoprotein nature of this enzyme.
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