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Khan SA, Ilies MA. Development and Optimization of a Bromothymol Blue-Based PLA2 Assay Involving POPC-Based Self-Assemblies. Int J Mol Sci 2024; 25:9517. [PMID: 39273463 PMCID: PMC11395447 DOI: 10.3390/ijms25179517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2024] [Revised: 08/26/2024] [Accepted: 08/30/2024] [Indexed: 09/15/2024] Open
Abstract
Phospholipase A2 (PLA2) is a superfamily of phospholipase enzymes that dock at the water/oil interface of phospholipid assemblies, hydrolyzing the ester bond at the sn-2 position. The enzymatic activity of these enzymes differs based on the nature of the substrate, its supramolecular assemblies (micelle, liposomes), and their composition, reflecting the interfacial nature of the PLA2s and requiring assays able to directly quantify this interaction of the enzyme(s) with these supramolecular assemblies. We developed and optimized a simple, universal assay method employing the pH-sensitive indicator dye bromothymol blue (BTB), in which different POPC (3-palmitoyl-2-oleoyl-sn-glycero-1-phosphocholine) self-assemblies (liposomes or mixed micelles with Triton X-100 at different molar ratios) were used to assess the enzymatic activity. We used this assay to perform a comparative analysis of PLA2 kinetics on these supramolecular assemblies and to determine the kinetic parameters of PLA2 isozymes IB and IIA for each supramolecular POPC assembly. This assay is suitable for assessing the inhibition of PLA2s with great accuracy using UV-VIS spectrophotometry, being thus amenable for screening of PLA2 enzymes and their substrates and inhibitors in conditions very similar to physiologic ones.
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Affiliation(s)
| | - Marc A. Ilies
- Department of Pharmaceutical Sciences, Moulder Center for Drug Discovery Research, Temple University, School of Pharmacy, 3307 N Broad Street, Philadelphia, PA 19130, USA;
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2
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A Novel Continuous Enzyme Coupled Colorimetric Assay for Phospholipase A2 and its Application in the Determination of Catalytic Activity of Oil-Body–Associated Oleosin Protein. FOOD ANAL METHOD 2022. [DOI: 10.1007/s12161-022-02284-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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3
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Veloso C, Videira RA, Andrade PB, Cardoso C, Vitorino C. Topical Fixed-Dose Combinations: Current in vitro methodologies for pre-clinical development. Int J Pharm 2022; 617:121621. [PMID: 35219825 DOI: 10.1016/j.ijpharm.2022.121621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 02/10/2022] [Accepted: 02/22/2022] [Indexed: 10/19/2022]
Abstract
The combination of two or more active pharmaceutical ingredients in the same dosage form - fixed-dose combination products - for topical administration represents a promising therapeutic approach for treating several pathologies, including pain. The pre-clinical development of fixed-dose combination products aims to characterize the interactions between the different APIs and ensure that the final medicinal product has the required safety characteristics. To this end, there are several regulatory accepted in vitro tests to assess the safety of medicinal products intended for cutaneous administration. In turn, the evaluation of anti-inflammatory activity should be based on models described in the scientific literature, as there are no models fully validated by competent entities. Therefore, the present work presents the information regarding accepted in vitro tests to assess the safety of topical products and the most used methods to assess anti-inflammatory activity. Additionally, a new approach to select a fixed-dose combination product with the potential to enhance the therapeutic effects of the individual active pharmaceutical ingredients is rationalized by integrating the overall effects on several targets relevant for inflammation and pain management in one numeric index.
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Affiliation(s)
- Cláudia Veloso
- Faculty of Pharmacy, University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal; Coimbra Chemistry Center, Department of Chemistry, University of Coimbra, Rua Larga, 3004-535 Coimbra, Portugal
| | - Romeu A Videira
- REQUIMTE/LAQV, Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, n° 228, 4050-313 Porto, Portugal.
| | - Paula B Andrade
- REQUIMTE/LAQV, Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, n° 228, 4050-313 Porto, Portugal
| | - Catarina Cardoso
- Laboratórios Basi, Parque Industrial Manuel Lourenço Ferreira, lote 15, 3450-232 Mortágua, Portugal
| | - Carla Vitorino
- Faculty of Pharmacy, University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal; Coimbra Chemistry Center, Department of Chemistry, University of Coimbra, Rua Larga, 3004-535 Coimbra, Portugal.
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4
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Xu Y, Li H, Xu D, Li J, Yu F, Wang M, Wang Q, Wu Y, Zhang Q, Tang Y, Yu J. Identification, expression and enzyme activity of the group III sPLA 2 s in Cyprinus carpio L. JOURNAL OF FISH BIOLOGY 2021; 99:25-36. [PMID: 33534139 DOI: 10.1111/jfb.14694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 02/02/2021] [Indexed: 06/12/2023]
Abstract
Five group III secreted phospholipase (pla2g3s) homologous genes located on different linkage groups were identified from common carp (Cyprinus carpio), which we named Ccpla2g3a1, Ccpla2g3a2, Ccpla2g3b, Ccpla2g3c1 and Ccpla2g3c2. The five genes encode 530, 525, 461, 752 and 753 amino acids, respectively. Sequence analysis showed that the Ccpla2g3as contain seven exons and the others contain four exons. Synteny analysis of fish pla2g3s indicated that pla2g3a and pla2g3b were from the same ancestor gene, and Ccpla2g3a1, Ccpla2g3a2, Ccpla2g3c1 and Ccpla2g3c2 were from the specific genome duplication of common carp. Due to the significant variation of the pla2g3bs from common carp and zebrafish (Danio rerio), they formed a separate group in the phylogenetic tree. The tissue distributions of Ccpla2g3s coincided with their expression profiles during the embryo stages. The expression levels of Ccpla2g3as and Ccpla2g3cs were low at the embryo stages, and they were abundant in the liver and brain, respectively, whereas the expression of Ccpla2g3b was high at 0.5 h after fertilization and in the ovary. We obtained three soluble recombinant proteins of the bee venom-like PLA2 (BVLP) from Ccpla2g3 and evaluated their PLA2 enzyme properties. The optimum pHs of MBP-a1-BVLP, MBP-b-BVLP and MBP-c1-BVLP were 7.5, 7.0 and 8.0, respectively, and specific activities were 7.68 ± 0.66, 4.155 ± 0.158 and 1.93 ± 0.05 U μmol-1 , respectively. The Kd for Ca2+ of MBP-b-BVLP was the lowest (2.6 μM), whereas the values for both MBP-a1-BVLP and MBP-c1-BVLP were about 15 μM. The Km values of three proteins ranged from 31.9 to 41.91 μM.
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Affiliation(s)
- Yuxin Xu
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi, China
| | - Hongxia Li
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi, China
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
| | - Dihui Xu
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi, China
| | - Jianlin Li
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
| | - Fan Yu
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
| | - Meiyao Wang
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
| | - Qin Wang
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi, China
| | - Yunsheng Wu
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi, China
| | - Qiyuan Zhang
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi, China
| | - Yongkai Tang
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi, China
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
| | - Juhua Yu
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi, China
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
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5
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Pereira RB, Pereira DM, Jiménez C, Rodríguez J, Nieto RM, Videira RA, Silva O, Andrade PB, Valentão P. Anti-Inflammatory Effects of 5α,8α-Epidioxycholest-6-en-3β-ol, a Steroidal Endoperoxide Isolated from Aplysia depilans, Based on Bioguided Fractionation and NMR Analysis. Mar Drugs 2019; 17:E330. [PMID: 31163615 PMCID: PMC6628248 DOI: 10.3390/md17060330] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 05/27/2019] [Accepted: 05/29/2019] [Indexed: 01/17/2023] Open
Abstract
Sea hares of Aplysia genus are recognized as a source of a diverse range of metabolites. 5α,8α-Endoperoxides belong to a group of oxidized sterols commonly found in marine organisms and display several bioactivities, including antimicrobial, anti-tumor, and immunomodulatory properties. Herein we report the isolation of 5α,8α-epidioxycholest-6-en-3β-ol (EnP(5,8)) from Aplysia depilans Gmelin, based on bioguided fractionation and nuclear magnetic resonance (NMR) analysis, as well as the first disclosure of its anti-inflammatory properties. EnP(5,8) revealed capacity to decrease cellular nitric oxide (NO) levels in RAW 264.7 macrophages treated with lipopolysaccharide (LPS) by downregulation of the Nos2 (inducible nitric oxide synthase, iNOS) gene. Moreover, EnP(5,8) also inhibited the LPS-induced expression of cyclooxygenase-2 (COX-2), interleukin 6 (IL-6), and tumor necrosis factor alpha (TNF-α) at the mRNA and protein levels. Mild selective inhibition of COX-2 enzyme activity was also evidenced. Our findings provide evidence of EnP(5,8) as a potential lead drug molecule for the development of new anti-inflammatory agents.
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Affiliation(s)
- Renato B Pereira
- REQUIMTE/LAQV, Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, nº 228, 4050-313 Porto, Portugal.
| | - David M Pereira
- REQUIMTE/LAQV, Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, nº 228, 4050-313 Porto, Portugal.
| | - Carlos Jiménez
- Departamento de Química, Facultade de Ciencias e Centro de Investigacións Científicas Avanzadas (CICA), Universidade da Coruña, E-15071 A Coruña, Spain.
| | - Jaime Rodríguez
- Departamento de Química, Facultade de Ciencias e Centro de Investigacións Científicas Avanzadas (CICA), Universidade da Coruña, E-15071 A Coruña, Spain.
| | - Rosa M Nieto
- Departamento de Química, Facultade de Ciencias e Centro de Investigacións Científicas Avanzadas (CICA), Universidade da Coruña, E-15071 A Coruña, Spain.
| | - Romeu A Videira
- REQUIMTE/LAQV, Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, nº 228, 4050-313 Porto, Portugal.
| | - Olga Silva
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Professor Gama Pinto, 1649-003 Lisbon, Portugal.
| | - Paula B Andrade
- REQUIMTE/LAQV, Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, nº 228, 4050-313 Porto, Portugal.
| | - Patrícia Valentão
- REQUIMTE/LAQV, Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, nº 228, 4050-313 Porto, Portugal.
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6
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A Midgut Digestive Phospholipase A 2 in Larval Mosquitoes, Aedes albopictus and Culex quinquefasciatus. Enzyme Res 2018; 2018:9703413. [PMID: 29862070 PMCID: PMC5976925 DOI: 10.1155/2018/9703413] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 04/12/2018] [Indexed: 11/18/2022] Open
Abstract
Phospholipase A2 (PLA2) is a secretory digestive enzyme that hydrolyzes ester bond at sn-2 position of dietary phospholipids, creating free fatty acid and lysophospholipid. The free fatty acids (arachidonic acid) are absorbed into midgut cells. Aedes albopictus and Culex quinquefasciatus digestive PLA2 was characterized using a microplate PLA2 assay. The enzyme showed substantial activities at 6 and 8 μg/μl of protein concentration with optimal activity at 20 and 25 μg/μl of substrate concentration in Aedes albopictus and Culex quinquefasciatus, respectively. PLA2 activity from both mosquitoes increased in a linear function up to 1 hour of the reaction time. Both enzymes were sensitive to pH and temperature. PLA2 showed higher enzyme activities in pH 8.0 and pH 9.0 from Aedes albopictus and Culex quinquefasciatus, respectively, at 40°C of incubation. The PLA2 activity decreased in the presence of 5 mM (Aedes albopictus) and 0.5 mM (Culex quinquefasciatus) site specific PLA2 inhibitor, oleyloxyethylphosphorylcholine. Based on the migration pattern of the partially purified PLA2 on SDS-PAGE, the protein mass of PLA2 is approximately 20–25 kDa for both mosquitoes. The information on PLA2 properties derived from this study may facilitate in devising mosquitoes control strategies especially in the development of inhibitors targeting the enzyme active site.
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7
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UHPLC-MS/MS profiling of Aplysia depilans and assessment of its potential therapeutic use: Interference on iNOS expression in LPS-stimulated RAW 264.7 macrophages and caspase-mediated pro-apoptotic effect on SH-SY5Y cells. J Funct Foods 2017. [DOI: 10.1016/j.jff.2017.07.053] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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8
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Anti-inflammatory properties of the stem bark from the herbal drug Vitex peduncularis Wall. ex Schauer and characterization of its polyphenolic profile. Food Chem Toxicol 2017; 106:8-16. [PMID: 28502822 DOI: 10.1016/j.fct.2017.05.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 04/13/2017] [Accepted: 05/11/2017] [Indexed: 12/22/2022]
Abstract
Vitex spp. have been reported as constituents of herbal preparations, namely Vitex peduncularis, commonly used in Asian countries. Unlike other species extensively investigated, reports on the biological activities and chemical profile of V. peduncularis are still scarce. In this work, the polyphenolic profile of V. peduncularis stem bark was unveiled, revealing a high content of apigenin and luteolin derivatives. More than 20 polyphenols were identified and quantitated for the first time, including C-rhamnosyl flavones infrequently reported. Regarding potential anti-inflammatory properties, the methanolic extract of the stem bark significantly reduced the levels of NO in macrophages, which may be a consequence of scavenging effect upon •NO. Significant inhibition of phospholipase A2 activity was also noted. Consequently, the therapeutic applicability of this edible plant is also broadened due to the anti-inflammatory properties found.
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9
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Exploratory Studies on the in Vitro
Anti-inflammatory Potential of Two Herbal Teas (Annona muricata
L. and Jasminum grandiflorum
L.), and Relation with Their Phenolic Composition. Chem Biodivers 2017; 14. [DOI: 10.1002/cbdv.201700002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 02/24/2017] [Indexed: 01/04/2023]
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10
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In Vitro Anti-Inflammatory and Cytotoxic Effects of Aqueous Extracts from the Edible Sea Anemones Anemonia sulcata and Actinia equina. Int J Mol Sci 2017; 18:ijms18030653. [PMID: 28304352 PMCID: PMC5372665 DOI: 10.3390/ijms18030653] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 03/09/2017] [Accepted: 03/14/2017] [Indexed: 12/16/2022] Open
Abstract
Marine invertebrates have been attracting the attention of researchers for their application in nutrition, agriculture, and the pharmaceutical industry, among others. Concerning sea anemones (Cnidaria), little is known regarding their metabolic profiles and potential value as a source of pharmacologically-active agents. In this work, the chemical profiles of two species of sea anemones Actinia equina and Anemonia sulcata, were studied by high-performance liquid chromatography with diode-array detection (HPLC-DAD) and its impact upon immune and gastric cells was evaluated. In both species, the methylpyridinium alkaloid homarine was the major compound in aqueous extracts. The extracts were effective in reducing lipopolysaccharide (LPS)-induced levels of nitric oxide (NO) and intracellular reactive oxygen species (ROS) in a macrophage model of inflammation. Both the extracts and the alkaloid homarine were effective in inhibiting phospholipase A₂ (PLA₂), a pivotal enzyme in the initial steps of the inflammatory cascade. In order to mimic the oral consumption of these extracts; their effect upon human gastric cells was evaluated. While no caspase-9 activation was detected, the fact that the endoplasmic reticulum-resident caspase-4, and also caspase-3, were activated points to a non-classical mechanism of apoptosis in human gastric cells. This work provides new insights on the toxicity and biological potential of sea anemones increasingly present in human nutrition.
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11
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Kumari S, Memba LJ, Dahuja A, Vinutha T, Saha S, Sachdev A. Elucidation of the role of oleosin in off-flavour generation in soymeal through supercritical CO₂ and biotic elicitor treatments. Food Chem 2016; 205:264-71. [PMID: 27006239 DOI: 10.1016/j.foodchem.2016.03.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 02/22/2016] [Accepted: 03/08/2016] [Indexed: 11/28/2022]
Abstract
Defatting soybean by sophisticated oil extraction method utilising supercritical CO2 resulted in a significant decrease in the residual phospholipids (PLs) compared with soymeal obtained by conventional cold percolation method utilising hexane as the extraction solvent. Interestingly, the levels of residual PLs showed a proportionate relationship with thiobarbituric acid (TBA) number, an indicator of lipid peroxidation responsible for off-flavour generation. Furthermore, two oleosins (18 and 24 kDa) were isolated from the oil bodies extracted from soybean seeds and positively characterised for phospholipase A2 (PLA2) activity, suggesting their plausible involvement in off-flavour generation in soymeal. The treatment of soybean seeds, before oil extraction, with different concentrations of biotic elicitors such as chitosan and jasmonic acid also significantly reduced the levels of residual PLs as well as the TBA number. The biotic elicitor treatment could thus prove to be an important strategy for the reduction of off-flavour in protein-rich soymeal.
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Affiliation(s)
- Sweta Kumari
- Division of Biochemistry, Indian Agricultural Research Institute, New Delhi 110012, India.
| | - Lucia Joseph Memba
- Division of Biochemistry, Indian Agricultural Research Institute, New Delhi 110012, India
| | - Anil Dahuja
- Division of Biochemistry, Indian Agricultural Research Institute, New Delhi 110012, India.
| | - T Vinutha
- Division of Biochemistry, Indian Agricultural Research Institute, New Delhi 110012, India
| | - Supradip Saha
- Division of Agricultural Chemicals, Indian Agricultural Research Institute, New Delhi 110012, India
| | - Archana Sachdev
- Division of Biochemistry, Indian Agricultural Research Institute, New Delhi 110012, India
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12
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Becerra-Amezcua MP, Guerrero-Legarreta I, González-Márquez H, Guzmán-García X. In vivo analysis of effects of venom from the jellyfish Chrysaora sp. in zebrafish (Danio rerio). Toxicon 2016; 113:49-54. [DOI: 10.1016/j.toxicon.2016.02.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 01/27/2016] [Accepted: 02/09/2016] [Indexed: 12/29/2022]
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13
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Li J, Zhang Y, Ai J, Gao Q, Qi H, Zhang C, Cheng Z. Quantum dot cluster (QDC)-loaded phospholipid micelles as a FRET probe for phospholipase A 2 detection. RSC Adv 2016; 6:15895-15899. [PMID: 26998254 PMCID: PMC4792299 DOI: 10.1039/c5ra25292j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
A simple assay for phospholipase A2 (PLA2) enzyme was developed based on a fluorescence resonance energy transfer (FRET) probe using the quantum dot cluster (QDC)-loaded phospholipid micelles. The probe was prepared by encapsulating many small hydrophobic quantum dots (QDs) within the hydrophobic core of micelles that were formed from the coassembly of hydrogenated soy phosphatidylcholine phospholipids (HSPC) and fluorescent lipids (NBD-PC). QDCs formed within the micelle core served as the substrate for NBD fluorescence quenching through FRET. The QDC-loaded micelles showed very low background fluorescence. As the PLA2 enzyme selectively digested lipids, the NBD fluorescence was recovered from its quenched state, leading to the sensitive detection of PLA2. This assay provided a limit of detection (at a signal-to-noise ratio of 3) of 3 U/L for PLA2. In the presence of a PLA2 inhibitor, the fluorescent response of the sensor for PLA2 decreased, indicating that the assay could also be used for screening the PLA2 inhibitors.
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Affiliation(s)
- Junling Li
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710062, China
| | - Yonghua Zhang
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710062, China
| | - Junjie Ai
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710062, China
| | - Qiang Gao
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710062, China
| | - Honglan Qi
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710062, China
| | - Chengxiao Zhang
- Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710062, China
| | - Zhiliang Cheng
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
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14
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PID15, a novel 6 kDa secreted peptide, mediates Naja naja venom phospholipase A₂ induced apoptosis in isolated human peripheral lymphocytes. J Biomed Sci 2014; 21:66. [PMID: 25030355 PMCID: PMC4115167 DOI: 10.1186/s12929-014-0066-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 07/11/2014] [Indexed: 02/03/2023] Open
Abstract
Background Snake venoms are a complex mixture of active principles mainly peptides and proteins also including amino acids, nucleotides, free lipids, carbohydrates and metallic elements bound to proteins that interfere in several biological systems. In this study, we aimed to understand the mode of action of the apoptosis inducing ability of Naja naja venom phospholipase A2 (NV-PLA2) using isolated human peripheral lymphocytes. Results Human peripheral lymphocytes when incubated with Naja naja venom phospholipase A2 (NV-PLA2) induced up to 68% DNA fragmentation. The dialysed conditioned media obtained by incubating lymphocytes with NV-PLA2 at 15th min induced 44% DNA fragmentation, referred to as cmlp-active. Cmlp-active showed 20.5% increased protein concentration than the corresponding control condition media cmlp-c-15. Test for creatine kinase activity in cmlp-active proved negative and negligible amount of lactate dehydrogenase did not show significant DNA fragmentation. Fractionation of cmlp-active on Sephadex G-25 showed two peaks, major peak induced 38% DNA fragmentation, which was further rechromatographed on Sephadex G-25. The single peak obtained was named PID15 (Phospholipase A2Induced DNA fragmentation factor secreted at 15th min). Q-Tof MS/MS analysis of PID-15 showed it is a 6 kDa peptide. PID15 sequence analysis gave 40 amino acids in the following order, msilpcknvs iwvikdtaas dkevvlgsdr aikflylatg. The homology search for the sequence revealed it to be an Apoptosis Inducing Factor (AIF). Conclusion Results indicate that the secretion of PID15 is dependent on concentration of NV-PLA2 treatment, incubation time and also on temperature and the probable membrane origin of PID15 and not of cytosolic origin with apoptosis inducing ability.
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15
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Vidal PJ, López-Nicolás JM, Gandía-Herrero F, García-Carmona F. Inactivation of lipoxygenase and cyclooxygenase by natural betalains and semi-synthetic analogues. Food Chem 2014; 154:246-54. [PMID: 24518339 DOI: 10.1016/j.foodchem.2014.01.014] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Revised: 11/27/2013] [Accepted: 01/07/2014] [Indexed: 02/07/2023]
Abstract
Betalains are natural pigments characteristic of plants of the order Caryophyllales. In this work, the role of betalains in the anti-inflammatory activity described for plant extracts is analysed in terms of the inactivation of the enzymes involved in the biochemical response (lipoxygenase and cyclooxygenase). Pure natural betalains and semi-synthetic analogues are demonstrated to promote a significant reduction of the enzymes activity. Reactions were followed spectrophotometrically and by HPLC-DAD. Phenethylamine-betaxanthin was the most potent in the inactivation of cyclooxygenase, with a reduction of 32% of the control activity at 125μM, while the natural pigment betanidin and a betalain analogue derived from indoline resulted as the most potent inactivators of lipoxygenase, with IC50 values of 41.4 and 40.1μM, respectively. Molecular docking studies revealed that betalains interact with the lipoxygenase amino acids involved in substrate binding and with Tyr-385 and Ser-530 close to the cyclooxygenase active site, interfering in enzyme catalysis.
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Affiliation(s)
- Pedro J Vidal
- Departamento de Bioquímica y Biología Molecular A, Unidad Docente de Biología, Facultad de Veterinaria, Regional Campus of International Excellence "Campus Mare Nostrum", Universidad de Murcia, Murcia, Spain
| | - José M López-Nicolás
- Departamento de Bioquímica y Biología Molecular A, Unidad Docente de Biología, Facultad de Veterinaria, Regional Campus of International Excellence "Campus Mare Nostrum", Universidad de Murcia, Murcia, Spain; Murcia Biomedical Research Institute (IMIB), Murcia, Spain
| | - Fernando Gandía-Herrero
- Departamento de Bioquímica y Biología Molecular A, Unidad Docente de Biología, Facultad de Veterinaria, Regional Campus of International Excellence "Campus Mare Nostrum", Universidad de Murcia, Murcia, Spain; Murcia Biomedical Research Institute (IMIB), Murcia, Spain.
| | - Francisco García-Carmona
- Departamento de Bioquímica y Biología Molecular A, Unidad Docente de Biología, Facultad de Veterinaria, Regional Campus of International Excellence "Campus Mare Nostrum", Universidad de Murcia, Murcia, Spain; Murcia Biomedical Research Institute (IMIB), Murcia, Spain
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16
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Salehi P, Ayyari M, Bararjanian M, Ebrahimi SN, Aliahmadi A. Synthesis, antibacterial and antioxidant activity of novel 2,3-dihydroquinazolin-4(1H)-one derivatives of dehydroabietylamine diterpene. JOURNAL OF THE IRANIAN CHEMICAL SOCIETY 2013. [DOI: 10.1007/s13738-013-0330-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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17
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Trono D, Soccio M, Laus MN, Pastore D. The existence of phospholipase A(2) activity in plant mitochondria and its activation by hyperosmotic stress in durum wheat (Triticum durum Desf.). PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2013; 199-200:91-102. [PMID: 23265322 DOI: 10.1016/j.plantsci.2012.11.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Revised: 11/09/2012] [Accepted: 11/10/2012] [Indexed: 05/19/2023]
Abstract
The activity of mitochondrial phospholipase A(2) (PLA(2)) was shown for the first time in plants. It was observed in etiolated seedlings from durum wheat, barley, tomato, spelt and green seedlings of maize, but not in potato and topinambur tubers and lentil etiolated seedlings. This result was achieved by a novel spectrophotometric assay based on the coupled PLA(2)/lipoxygenase reactions using 1-palmitoyl-2-linoleoyl-sn-glycero-3-phosphatidylcholine as substrate; the mitochondrial localisation was assessed by checking recovery of marker enzymes. Durum wheat mitochondrial PLA(2) (DWM-PLA(2)) showed maximal activity at pH 9.0 and 1mM Ca(2+), hyperbolic kinetics (K(m)=90±6μM, V(max)=29±1nmolmin(-1)mg(-1) of protein) and inhibition by methyl arachidonyl fluorophosphonate, 5-(4-benzyloxyphenyl)-4S-(7-phenylheptanoylamino)pentanoic acid and palmityl trifluoromethyl ketone. Reactive oxygen species had no effect on DWM-PLA(2), that instead was activated by about 50% and 95%, respectively, under salt (0.21M NaCl) and osmotic (0.42M mannitol) stress imposed during germination. Contrarily, a secondary Ca(2+)-independent activity, having optimum at pH 7.0, was stress-insensitive. We propose that the activation of DWM-PLA(2) is responsible for the strong increase of free fatty acids recently measured in mitochondria under the same stress conditions [Laus, et al., J. Exp. Bot. 62 (2011) 141-154] that, in turn, activate potassium channel and uncoupling protein, able to counteract hyperosmotic stress.
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Affiliation(s)
- Daniela Trono
- Consiglio per la Ricerca e la sperimentazione in Agricoltura - Centro di Ricerca per la Cerealicoltura, Foggia, Italy
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18
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Recent progress on phospholipases: different sources, assay methods, industrial potential and pathogenicity. Appl Biochem Biotechnol 2011; 164:991-1022. [PMID: 21302142 DOI: 10.1007/s12010-011-9190-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2010] [Accepted: 01/25/2011] [Indexed: 10/18/2022]
Abstract
Significant studies on phospholipases optimization, characterization, physiological role and industrial potential have been conducted worldwide. Some of them have been directed for biotechnological advances such as gene discovery and functional enhancement by protein engineering. Others reported phospholipases as virulence factor and major cause of pathophysiological effects. A general overview on phospholipase is needed for the identification of new reliable and efficient phospholipase, which would be potentially used in number of industrial and medical applications. Phospholipases catalyse the hydrolysis of one or more ester and phosphodiester bonds of glycerophospholipids. They vary in site of action on phospholipid which can be used industrially for modification/production of new phospholipids. Catalytically active phospholipase mainly use phosphatidylcholine as major substrate, but they can also show specificity with other phospholipids. Several accurate phospholipase assay methods are known, but a rapid and reliable method for high-throughput screening is still a challenge for efficient supply of superior phospholipases and their practical applications. Major application of phospholipase is in industries like oil refinery, health food manufacturing, dairy, cosmetics etc. All types of phospholipases can be involved as virulence factor. They can also be used as diagnostic markers for microbial infection. The importance of phospholipase in virulence is proven and inhibitors of the enzyme can be used as candidate for preventing the associated disease.
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19
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Monti MC, Chini MG, Margarucci L, Tosco A, Riccio R, Bifulco G, Casapullo A. The molecular mechanism of human group IIA phospholipase A2 inactivation by bolinaquinone. J Mol Recognit 2010; 22:530-7. [PMID: 19621421 DOI: 10.1002/jmr.968] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The molecular basis of the human group IIA secretory phospholipase A(2) inactivation by bolinaquinone (BLQ), a hydroxyquinone marine terpenoid, has been investigated for the comprehension of its relevant antiinflammatory properties, through the combination of spectroscopic techniques, biosensors analysis, mass spectrometry (MS) and molecular docking. Indeed, sPLA(2)s are well known to be implicated in the pathogenesis of inflammation such as rheumatoid arthritis, septic shock, psoriasis and asthma. Our results suggest a mechanism of competitive inhibition guided by a non-covalent molecular recognition event, disclosing the key role of the BLQ hydroxyl-quinone moiety in the chelation of the catalytic Ca(2+) ion inside the enzyme active site.The understanding of the sPLA(2)-IIA inactivation mechanism by BLQ could be useful for the development of a new chemical class of PLA(2) inhibitors, able to specifically target the enzyme active site.
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Affiliation(s)
- Maria Chiara Monti
- Dipartimento di Scienze Farmaceutiche, Università di Salerno, via Ponte Don Melillo, Fisciano, Italy
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20
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Chemburu S, Ji E, Casana Y, Wu Y, Buranda T, Schanze KS, Lopez GP, Whitten DG. Conjugated polyelectrolyte supported bead based assays for phospholipase A2 activity. J Phys Chem B 2008; 112:14492-9. [PMID: 18808092 DOI: 10.1021/jp803358j] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A fluorescence based assay for human serum-derived phospholipase activity has been developed in which cationic conjugated polyelectrolytes are supported on silica microspheres. The polymer-coated beads are overcoated with an anionic phospholipid (1,2-dimyristoyl-sn-glycero-3-[phospho- rac-(1-glycerol)) (DMPG) to provide "lipobeads" that serve as a sensor for PLA2. The lipid serves a dual role as a substrate for PLA2 and an agent to attenuate quenching of the polymer fluorescence by the external electron transfer quencher 9,10-anthraquinone-2,6-disulfonic acid (AQS). In this case quenching of the polymer fluorescence by AQS increases as the PLA2 digests the lipid. The lipid can also be used itself as a quencher and substrate by employing a small amount of energy transfer quencher substituted lipid in the DMPG. In this case the fluorescence of the polymer is quenched when the lipid layer is intact; as the enzyme digests the lipid, the fluorescence of the polymer is restored. The sensing of PLA2 activity has been studied both by monitoring fluorescence changes in a multiwell plate reader and by flow cytometry. The assay exhibits good sensitivity with EC50 values in the nanomolar range.
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Affiliation(s)
- Sireesha Chemburu
- Department of Chemical and Nuclear Engineering, University of New Mexico, Albuquerque, New Mexico 87131, USA
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21
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Duncan RE, Sarkadi-Nagy E, Jaworski K, Ahmadian M, Sul HS. Identification and functional characterization of adipose-specific phospholipase A2 (AdPLA). J Biol Chem 2008; 283:25428-25436. [PMID: 18614531 PMCID: PMC2533091 DOI: 10.1074/jbc.m804146200] [Citation(s) in RCA: 122] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2008] [Revised: 07/09/2008] [Indexed: 12/24/2022] Open
Abstract
Phospholipases A(2) (PLA(2)s) catalyze hydrolysis of fatty acids from the sn-2 position of phospholipids. Here we report the identification and characterization of a membrane-associated intracellular calcium-dependent, adipose-specific PLA(2) that we named AdPLA (adipose-specific phospholipase A(2)). We found that AdPLA was highly expressed specifically in white adipose tissue and was induced during preadipocyte differentiation into adipocytes. Clearance of AdPLA by immunoprecipitation significantly decreased PLA activity in white adipose tissue lysates but had no effect on liver lysates, where expression was hardly detectable. In characterizing AdPLA, we employed radiochemical assays with TLC analysis of the enzyme activity of lysates from COS-7 cells overexpressing AdPLA. For kinetic studies, we produced purified recombinant AdPLA for use in a lipoxidase-coupled spectrophotometric assay. AdPLA generated free fatty acid and lysophospholipid from phosphatidylcholine with a preference for hydrolysis at the sn-2 position. Although we found low but detectable lysophospholipase activity, AdPLA showed no significant activity against a variety of other lipid substrates. Calcium was found to activate AdPLA but was not essential for activity. Studies with known phospholipase inhibitors, including bromoenolactone, methyl arachidonyl fluorophosphate, AACOCF(3), 7,7-dimethyl-5,8-eicosadienoic acid, and thioetheramide, supported that AdPLA is a phospholipase. Mutational studies showed that His-23 and Cys-113 are critical for activity of AdPLA and suggested that AdPLA is likely a His/Cys PLA(2). Overall, although AdPLA is similar to other histidine phospholipases in pH and calcium dependence, AdPLA showed different characteristics in many regards, including predicted catalytic mechanism. AdPLA may therefore represent the first member of a new group of PLA(2)s, group XVI.
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Affiliation(s)
- Robin E Duncan
- Department of Nutritional Science and Toxicology, University of California, Berkeley, California 94720
| | - Eszter Sarkadi-Nagy
- Department of Nutritional Science and Toxicology, University of California, Berkeley, California 94720
| | - Kathy Jaworski
- Department of Nutritional Science and Toxicology, University of California, Berkeley, California 94720
| | - Maryam Ahmadian
- Department of Nutritional Science and Toxicology, University of California, Berkeley, California 94720
| | - Hei Sook Sul
- Department of Nutritional Science and Toxicology, University of California, Berkeley, California 94720.
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22
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Chang HW, Jang KH, Lee D, Kang HR, Kim TY, Lee BH, Choi BW, Kim S, Shin J. Monoglycerides from the brown alga Sargassum sagamianum: Isolation, synthesis, and biological activity. Bioorg Med Chem Lett 2008; 18:3589-92. [PMID: 18487046 DOI: 10.1016/j.bmcl.2008.05.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2007] [Revised: 04/05/2008] [Accepted: 05/01/2008] [Indexed: 11/26/2022]
Abstract
Polyunsaturated fatty acid-derived monoglycerides were characterized from the marine brown alga Sargassum sagamianum, collected from Jeju Island, Korea. A new compound of this structural class was isolated and determined to be 1-octadecatetraenoyl glycerol, by combined spectroscopic methods. Based on the structures and bioactivity of these compounds, a series of monoglycerides were synthesized using glycerol and various fatty acids. Several compounds exhibited moderate to significant inhibition of phospholipase A(2) and cyclooxygenase-2.
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Affiliation(s)
- Hyeun Wook Chang
- College of Pharmacy, Youngnam University, 214-1, Dae, Gyeongsan, Gyeongsangbuk 712-749, Korea
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23
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Cunha Bastos VLF, Salles JB, Valente RH, León IR, Perales J, Dantas RF, Albano RM, Bastos FF, Cunha Bastos J. Cytosolic glutathione peroxidase from liver of pacu (Piaractus mesopotamicus), a hypoxia-tolerant fish of the Pantanal. Biochimie 2007; 89:1332-42. [PMID: 17544198 DOI: 10.1016/j.biochi.2007.04.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2006] [Accepted: 04/06/2007] [Indexed: 11/22/2022]
Abstract
Pacu (Piaractus mesopotamicus Holmberg, 1887, Characiformes) dwells in waters of Pantanal, in which it has adapted for alternate concentrations of dissolved oxygen. Intracellular antioxidant protection should be vital for such an adaptation. Accordingly, we found that cytosol from liver of pacu has the highest antioxidant glutathione peroxidase activity so far reported for fish and murine species. To clarify whether this activity was due to a selenium independent glutathione S-transferase or to a glutathione peroxidase, we purified it and studied its kinetics. The substrates cumene hydroperoxide and hydrogen peroxide were promptly reduced by the enzyme, but peroxidized phosphatidylcholine had to undergo previous fatty acid removal with phospholipase A(2). Augmenting concentrations (from 2 to 6 mM) of reduced glutathione activated the pure enzyme. Curves of velocity versus different micromolar concentrations of hydrogen peroxide in the presence of 2, 4 or 8 mM reduced glutathione indicated that at least 2.5 mM reduced glutathione should be available in vivo for an efficient continuous destruction of micromolar concentrations of hydrogen peroxide by this peroxidase. Molecular exclusion HPLC and SDS-polyacrylamide gel electrophoresis indicated that the purified peroxidase is a homotetramer. Data from internal sequences showed selenocysteine in its primary structure and that the enzyme was a homologue of the type-1 glutathione peroxidase found in rat, bull, trout, flounder and zebra fish. Altogether, our data establish that in liver cells of pacu, a hypoxia-tolerant fish from South America, there are high levels of a cytosolic GPX-1 capable of quenching hydrogen peroxide and fatty acid peroxides, providing an effective antioxidant action.
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Affiliation(s)
- V L F Cunha Bastos
- Department of Biochemistry, UERJ, Av Professor Manuel de Abreu, 444, Rio de Janeiro, RJ, Brazil
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24
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Huang LS, Kim MR, Sok DE. Linoleoyl lysophosphatidylcholine is an efficient substrate for soybean lipoxygenase-1. Arch Biochem Biophys 2006; 455:119-26. [PMID: 17067544 DOI: 10.1016/j.abb.2006.09.015] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2006] [Revised: 09/15/2006] [Accepted: 09/17/2006] [Indexed: 10/24/2022]
Abstract
Oxygenation of 1-linoleoyl lysophosphatidylcholine (linoleoyl-lysoPC) by soybean lipoxygenase-1 was monitored by measuring the increase of absorbance at 234nm. In support of this, the hydroperoxy derivative of linoleoyl-lysoPC as a major product and its reduction product as a minor one were detected by LC/MS analyses. The greater part of the hydroperoxy derivative was found to contain hydroperoxide group at C-13 rather than C-9, consistent with the position specificity of soybean lipoxygenase-1 in oxygenation of linoleic acid. Such a preferential production of 13-hydroperoxy derivative of linoleoyl-lysoPC was also observed at pH 7.4, suggesting that the positional specificity of lipoxygenase-1 is not affected greatly by pH. In addition, the pH-dependent oxygenation of linoleoyl-lysoPC, showing an optimal activity around pH 9, was similar to that of linoleic acid. In kinetic study, lipoxygenase 1-catalyzed oxygenation of linoleoyl-lysoPC followed Michaelis-Menten kinetics (V(m), 167.5U/mg protein; K(m), 12.9muM). In comparison, linoleoyl-lysoPC was no less efficient than linoleic acid as a substrate of soybean lipoxygenase-1. Moreover, oxygenation of linoleoyl-lysoPC by LOX-1 was not affected by detergent. Thus, linoleoyl-lysoPC could be utilized as a convenient substrate in the assay of soybean lipoxygeanse-1.
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Affiliation(s)
- Long Shuang Huang
- College of Pharmacy, Chungnam National University, Yuseong-ku, Taejon, Republic of Korea
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25
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Huang C, Zhou L, Liu Y, Lai L. A continuous fluorescence assay for phospholipase A2 with nontagged lipid. Anal Biochem 2006; 351:11-7. [PMID: 16510113 DOI: 10.1016/j.ab.2006.01.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2005] [Revised: 12/30/2005] [Accepted: 01/04/2006] [Indexed: 11/30/2022]
Abstract
Human nonpancreatic secreted phospholipase A2 (hnps PLA2) is considered to be an important drug target for antiinflammation therapy. We have established a new fluorescence assay by using 1-anilinonaphthalene-8-sulfonate (ANS) as an interfacial probe for hydrophobic environment detection. The fitted apparent k(cat)/K(m) of hnps PLA2 is 0.0181 +/- 0.0005 RFU/microMs. Tests on known synthesized inhibitor gave IC50 values similar to those from isotope-labeled assay. Because ANS is a commonly used probe for hydrophobic environment detection that needs no modification in the current assay, this strategy may be widely applicable for interfacial catalytic reactions.
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Affiliation(s)
- Changkang Huang
- State Key Laboratory for Structural Chemistry of Stable and Unstable Species, College of Chemistry, Peking University, Beijing 100871, China
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26
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Phospholipases: Occurrence and production in microorganisms, assay for high-throughput screening, and gene discovery from natural and man-made diversity. J AM OIL CHEM SOC 2005. [DOI: 10.1007/s11746-005-1131-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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27
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Caramelo JJ, Delfino JM. A subnanogram assay for phospholipase activity based on a long-chain radioiodinatable phosphatidylcholine. Anal Biochem 2004; 333:289-95. [PMID: 15450804 DOI: 10.1016/j.ab.2004.05.028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2004] [Indexed: 11/26/2022]
Abstract
Here, we introduce a radioiodinatable long-chain phosphatidylcholine (BHC12PC) which serves as the base for a very sensitive phospholipase assay. This compound has a 4-hydroxyphenyl group attached at the end of the fatty acyl chain located in position sn-2. This feature enables this phospholipid to be radioiodinated. BHC12PC was tested as a substrate of Naja naja naja PLA(2) and Bacillus cereus PLC in a mixed micellar system with Triton X-100. The detection limit for the assays was 0.25ng of PLA(2) and 0.05ng of PLC, thus becoming one of the most sensitive methods described so far. A low specific radioactivity (500microCi/mmol) suffices to achieve this level of sensitivity. In both cases, the behavior of BHC12PC was indistinguishable from that shown by phospholipids with n-acyl chains of similar length. The choice of spacer prevents any unfavorable interaction of the bulky 4-hydroxyphenyl group at the active site of the enzymes. The progress of the reaction as monitored by thin-layer chromatography is compared side by side with an alternative method based on the selective adsorption of BHC12PC to silica gel, which renders identical results in a simpler fashion. An additional advantage of BHC12PC is that the cost per Ci of the radioiodinated derivative is significantly lower than that of other labeled phospholipids ((3)H, (14)C, or (32)P).
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Affiliation(s)
- Julio J Caramelo
- Institute of Biophysics and Biochemistry, School of Pharmacy and Biochemistry, University of Buenos Aires, Junín 956, RA-1113 Buenos Aires, Argentina.
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