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Henquet MGL, Roelse M, de Vos RCH, Schipper A, Polder G, de Ruijter NCA, Hall RD, Jongsma MA. Metabolomics meets functional assays: coupling LC-MS and microfluidic cell-based receptor-ligand analyses. Metabolomics 2016; 12:115. [PMID: 27398080 PMCID: PMC4917570 DOI: 10.1007/s11306-016-1057-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 06/13/2016] [Indexed: 12/02/2022]
Abstract
INTRODUCTION Metabolomics has become a valuable tool in many research areas. However, generating metabolomics-based biochemical profiles without any related bioactivity is only of indirect value in understanding a biological process. Therefore, metabolomics research could greatly benefit from tools that directly determine the bioactivity of the detected compounds. OBJECTIVE We aimed to combine LC-MS metabolomics with a cell based receptor assay. This combination could increase the understanding of biological processes and may provide novel opportunities for functional metabolomics. METHODS We developed a flow through biosensor with human cells expressing both the TRPV1, a calcium ion channel which responds to capsaicin, and the fluorescent intracellular calcium ion reporter, YC3.6. We have analysed three contrasting Capsicum varieties. Two were selected with contrasting degrees of spiciness for characterization by HPLC coupled to high mass resolution MS. Subsequently, the biosensor was then used to link individual pepper compounds with TRPV1 activity. RESULTS Among the compounds in the crude pepper fruit extracts, we confirmed capsaicin and also identified both nordihydrocapsaicin and dihydrocapsaicin as true agonists of the TRPV1 receptor. Furthermore, the biosensor was able to detect receptor activity in extracts of both Capsicum fruits as well as a commercial product. Sensitivity of the biosensor to this commercial product was similar to the sensory threshold of a human sensory panel. CONCLUSION Our results demonstrate that the TRPV1 biosensor is suitable for detecting bioactive metabolites. Novel opportunities may lie in the development of a continuous functional assay, where the biosensor is directly coupled to the LC-MS.
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Affiliation(s)
- M. G. L. Henquet
- BU Bioscience, WageningenUR, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - M. Roelse
- BU Bioscience, WageningenUR, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
- Laboratory of Plant Physiology, WageningenUR, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - R. C. H. de Vos
- BU Bioscience, WageningenUR, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
- Netherlands Metabolomics Centre, Einsteinweg 55, 3335 CC Leiden, The Netherlands
| | - A. Schipper
- BU Bioscience, WageningenUR, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - G. Polder
- BU Bioscience, WageningenUR, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - N. C. A. de Ruijter
- Laboratory of Cell Biology, WageningenUR, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - R. D. Hall
- BU Bioscience, WageningenUR, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
- Netherlands Metabolomics Centre, Einsteinweg 55, 3335 CC Leiden, The Netherlands
- Laboratory of Plant Physiology, WageningenUR, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - M. A. Jongsma
- BU Bioscience, WageningenUR, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
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Laborde C, Pittino F, Verhoeven HA, Lemay SG, Selmi L, Jongsma MA, Widdershoven FP. Real-time imaging of microparticles and living cells with CMOS nanocapacitor arrays. Nat Nanotechnol 2015; 10:791-5. [PMID: 26237346 DOI: 10.1038/nnano.2015.163] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 06/25/2015] [Indexed: 05/03/2023]
Abstract
Platforms that offer massively parallel, label-free biosensing can, in principle, be created by combining all-electrical detection with low-cost integrated circuits. Examples include field-effect transistor arrays, which are used for mapping neuronal signals and sequencing DNA. Despite these successes, however, bioelectronics has so far failed to deliver a broadly applicable biosensing platform. This is due, in part, to the fact that d.c. or low-frequency signals cannot be used to probe beyond the electrical double layer formed by screening salt ions, which means that under physiological conditions the sensing of a target analyte located even a short distance from the sensor (∼1 nm) is severely hampered. Here, we show that high-frequency impedance spectroscopy can be used to detect and image microparticles and living cells under physiological salt conditions. Our assay employs a large-scale, high-density array of nanoelectrodes integrated with CMOS electronics on a single chip and the sensor response depends on the electrical properties of the analyte, allowing impedance-based fingerprinting. With our platform, we image the dynamic attachment and micromotion of BEAS, THP1 and MCF7 cancer cell lines in real time at submicrometre resolution in growth medium, demonstrating the potential of the platform for label/tracer-free high-throughput screening of anti-tumour drug candidates.
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Affiliation(s)
- C Laborde
- MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, Enschede 7500 AE, Netherlands
| | - F Pittino
- DIEGM, University of Udine, Via delle Scienze 206, 33100, Udine, Italy
| | - H A Verhoeven
- PRI-Bioscience, Wageningen University and Research Centre, PO Box 16, Wageningen 6700 AA, Netherlands
| | - S G Lemay
- MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, Enschede 7500 AE, Netherlands
| | - L Selmi
- DIEGM, University of Udine, Via delle Scienze 206, 33100, Udine, Italy
| | - M A Jongsma
- PRI-Bioscience, Wageningen University and Research Centre, PO Box 16, Wageningen 6700 AA, Netherlands
| | - F P Widdershoven
- NXP Semiconductors, Technology &Operations/CTO office, High Tech Campus 46, Eindhoven 5656 AE, Netherlands
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Prota N, Mumm R, Bouwmeester HJ, Jongsma MA. Comparison of the chemical composition of three species of smartweed (genus Persicaria) with a focus on drimane sesquiterpenoids. Phytochemistry 2014; 108:129-136. [PMID: 25453911 DOI: 10.1016/j.phytochem.2014.10.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 09/26/2014] [Accepted: 10/01/2014] [Indexed: 06/04/2023]
Abstract
The genus Persicaria is known to include species accumulating drimane sesquiterpenoids, but a comparative analysis highlighting the compositional differences has not been done. In this study, the secondary metabolites of both flowers and leaves of Persicariahydropiper, Persicariamaculosa and Persicariaminor, three species which occur in the same habitat, were compared. Using gas chromatography-mass spectrometry (GC-MS) analysis of extracts, overall 21/29 identified compounds in extracts were sesquiterpenoids and 5/29 were drimanes. Polygodial was detected in all species, though not in every sample of P. maculosa. On average, P. hydropiper flowers contained about 6.2 mg g FW(-1) of polygodial, but P. minor flowers had 200-fold, and P. maculosa 100,000 fold lower concentrations. Comparatively, also other sesquiterpenes were much lower in those species, suggesting the fitness benefit to depend on either investing a lot or not at all in terpenoid-based secondary defences. For P. hydropiper, effects of flower and leaf development and headspace volatiles were analysed as well. The flower stage immediately after fertilisation was the one with the highest content of drimane sesquiterpenoids and leaves contained about 10-fold less of these compounds compared to flowers. The headspace of P. hydropiper contained 8 compounds: one monoterpene, one alkyl aldehyde and six sesquiterpenes, but none were drimanes. The potential ecological significance of the presence or absence of drimane sesquiterpenoids and other metabolites for these plant species are discussed.
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Affiliation(s)
- N Prota
- Plant Research International, PO Box 619, 6700 AP Wageningen, The Netherlands; Laboratory of Plant Physiology, Wageningen University, PO Box 658, 6700 AR Wageningen, The Netherlands
| | - R Mumm
- Plant Research International, PO Box 619, 6700 AP Wageningen, The Netherlands; Centre for BioSystems Genomics, PO Box 98, 6700 AB Wageningen, The Netherlands
| | - H J Bouwmeester
- Laboratory of Plant Physiology, Wageningen University, PO Box 658, 6700 AR Wageningen, The Netherlands
| | - M A Jongsma
- Plant Research International, PO Box 619, 6700 AP Wageningen, The Netherlands.
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Outchkourov NS, Peters J, de Jong J, Rademakers W, Jongsma MA. The promoter-terminator of chrysanthemum rbcS1 directs very high expression levels in plants. Planta 2003; 216:1003-12. [PMID: 12687368 DOI: 10.1007/s00425-002-0953-8] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2002] [Accepted: 11/11/2002] [Indexed: 05/19/2023]
Abstract
Transgenic plants are increasingly used as production platforms for various proteins, yet protein expression levels in the range of the most abundant plant protein, ribulose-1,5-bisphosphate carboxylase have not yet been achieved by nuclear transformation. Suitable gene regulatory 5' and 3' elements are crucial to obtain adequate expression. In this study an abundantly transcribed member (rbcS1) of the ribulose-1,5-bisphosphate carboxylase small-subunit gene family of chrysanthemum (Chrysanthemum morifolium Ramat.) was cloned. The promoter of rbcS1 was found to be homologous to promoters of highly expressed rbcS gene members of the plant families Asteraceae, Fabaceae and Solanaceae. The regulatory 5' and 3' non-translated regions of rbcS1 were engineered to drive heterologous expression of various genes. In chrysanthemum, the homologous rbcS1 cassette resulted in a beta-glucuronidase (gusA) accumulation of, at maximum, 0.88% of total soluble protein (population mean 0.17%). In tobacco (Nicotiana tabacum L.), the gusA expression reached 10% of total soluble protein. The population mean of 2.7% was found to be 7- to 8-fold higher than for the commonly used cauliflower mosaic virus (CaMV) 35S promoter (population mean 0.34%). RbcS1-driven expression of sea anemone equistatin in potato (Solanum tuberosum L.), and potato cystatin in tomato (Lycopersicon esculentum Mill.) yielded maximum levels of 3-7% of total soluble protein. The results demonstrate, that the compact 2-kb rbcS1 expression cassette provides a novel nuclear transformation vector that generates plants with expression levels of up to 10% of total protein.
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Affiliation(s)
- N S Outchkourov
- Plant Research International, PO Box 16, 6700AA, Wageningen, The Netherlands
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Balkema-Boomstra AG, Zijlstra S, Verstappen FWA, Inggamer H, Mercke PE, Jongsma MA, Bouwmeester HJ. Role of cucurbitacin C in resistance to spider mite (Tetranychus urticae) in cucumber (Cucumis sativus L.). J Chem Ecol 2003; 29:225-35. [PMID: 12647864 DOI: 10.1023/a:1021945101308] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Cucurbitacins are bitter triterpenoid compounds that are toxic to most organisms and occur widely in wild and cultivated Cucurbitaceae. The only cucurbitacin identified in Cucumis sativus is cucurbitacin C. The bitter taste of cucumber has been correlated with resistance to the spider mite Tetranychus urticae, but a quantitative relationship has not been established. We determined the spider mite resistance and cucurbitacin C content in the dihaploid progeny derived from the F1 generation of a cross between a bitter, spider-mite-resistant cucumber line and a bitter-free, spider-mite-susceptible line. The ratio of the number of bitter to bitter-free dihaploids conformed to the expected 1:1 ratio, based on a monogenic segregation pattern. Genetic analysis ascribed 69% of the variance of the difference in spider mite survival rate to the bitterness locus. Within the group of bitter dihaploids, cucurbitacin C content was significantly correlated with spider mite resistance. Thus, a quantitative relationship between cucurbitacin C content and spider mite resistance could be established.
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Annadana S, Beekwilder MJ, Kuipers G, Visser PB, Outchkourov N, Pereira A, Udayakumar M, De Jong J, Jongsma MA. Cloning of the chrysanthemum UEP1 promoter and comparative expression in florets and leaves of Dendranthema grandiflora. Transgenic Res 2002; 11:437-45. [PMID: 12212845 DOI: 10.1023/a:1016313924844] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
To attain high transgene expression in petal tissue of ray florets of chrysanthemum an endogenous ubiquitin extension protein (UEP1) promoter was cloned and tested with the beta-glucuronidase (GUS) reporter gene. Expression levels were compared with four heterologous promoters: chalcone synthase (chs-A) and zinc finger transcription factor (EPF2-5) from petunia, eceriferum (CER6) from Arabidopsis and multicystatin (PMC) from potato. The comparison of the expression levels of the different constructs in ray florets, disc florets, and leaves is presented. The highest mean expression in petal tissue of ray and disc florets was conferred by the UEP1 promoter, followed by CER6 and EPF2-5. The UEP1 promoter in ray florets confers over 50-fold enhancement in expression as compared to CaMV 35S-based promoters.
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Affiliation(s)
- S Annadana
- Department of Crop Physiology, University of Agricultural Sciences, Bangalore, India
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Estébanez-Perpiñá E, Bayés A, Vendrell J, Jongsma MA, Bown DP, Gatehouse JA, Huber R, Bode W, Avilés FX, Reverter D. Crystal structure of a novel mid-gut procarboxypeptidase from the cotton pest Helicoverpa armigera. J Mol Biol 2001; 313:629-38. [PMID: 11676544 DOI: 10.1006/jmbi.2001.5076] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The cotton bollworm Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) is one of the most serious insect pests in Australia, India and China. The larva causes substantial economical losses to legume, fibre, cereal oilseed and vegetable crops. This pest has proven to be difficult to control by conventional means, mainly due to the development of pesticide resistance. We present here the 2.5 A crystal structure from the novel procarboxypeptidase (PCPAHa) found in the gut extracts from H. armigera larvae, the first one reported for an insect. This metalloprotease is synthesized as a zymogen of 46.6 kDa which, upon in vitro activation with Lys-C endoproteinase, yields a pro-segment of 91 residues and an active carboxypeptidase moiety of 318 residues. Both regions show a three-dimensional structure quite similar to the corresponding structures in mammalian digestive carboxypeptidases, the most relevant structural differences being located in the loops between conserved secondary structure elements, including the primary activation site. This activation site contains the motif (Ala)(5)Lys at the C terminus of the helix connecting the pro- and the carboxypeptidase domains. A remarkable feature of PCPAHa is the occurrence of the same (Ala)(6)Lys near the C terminus of the active enzyme. The presence of Ser255 in PCPAHa instead of Ile and Asp found in the pancreatic A and B forms, respectively, enlarges the S1' specificity pocket and influences the substrate preferences of the enzyme. The C-terminal tail of the leech carboxypeptidase inhibitor has been modelled into the PCPAHa active site to explore the substrate preferences and the enzymatic mechanism of this enzyme.
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Affiliation(s)
- E Estébanez-Perpiñá
- Abteilung für Strukturforschung, Max-Planck-Institut für Biochemie, Am Klopferspitz 18a, D-82152 Planegg-Martinsried, Germany
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Volpicella M, Ceci LR, Gallerani R, Jongsma MA, Beekwilder J. Functional expression on bacteriophage of the mustard trypsin inhibitor MTI-2. Biochem Biophys Res Commun 2001; 280:813-7. [PMID: 11162593 DOI: 10.1006/bbrc.2000.4182] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The mustard trypsin inhibitor MTI-2 is a potential tool in the study of interactions between pest insects and plants. It can be applied to study the adaptations of digestive proteases in pest insects. Phage display allows a rapid and exhaustive system for the selection of heterologous protein variants with novel specificities. Here we describe a bacteriophage expression system which permits functional expression of MTI-2 variants. Active and inactive mutants of MTI-2 are constructed and displayed on phage. These are used to demonstrate that an active variant can be selected from a background of 10,000 inactive mutants in four rounds of selection and amplification.
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Affiliation(s)
- M Volpicella
- Dipartimento di Biochimica e Biologia Molecolare, Universita' di Bari, Via Amendola 165/A, 70126 Bari, Italy.
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Abstract
Equistatin (EI) is a cysteine protease inhibitor that was isolated from the sea anemone Actinia equina. It belongs to a recently discovered group of thyroglobulin type-I domain inhibitors called thyropins. Since native EI is found only in low amounts in the body of sea anemone and expression of recombinant EI in Escherichia coli yielded only 1 mg/liter of protein, we used the Pichia pastoris expression system to obtain higher yields. A cDNA encoding EI was inserted into pPIC9 vector and transformed into the P. pastoris, strain GS115. Clones expressing high levels of EI were selected from 48 transformants. Recombinant EI was produced in 2-liter shake flasks and recovered from the fermentation broth by affinity chromatography using CM-papain-Sepharose. SDS-PAGE and N-terminal sequence analysis revealed that EI was N-terminally intact and running at the expected molecular weight of 22 kDa. The equilibrium dissociation constants of EI with papain and bovine cathepsin D were determined and were found to be similar to the results for the native inhibitor. EI production was scaled up to a bench top fermentor with a 25 mg/liter yield of active EI.
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Affiliation(s)
- B Rogelj
- Jozef Stefan Institute, Jamova 39, Ljubljana, SI-1000, Slovenia
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Strukelj B, Lenarcic B, Gruden K, Pungercar J, Rogelj B, Turk V, Bosch D, Jongsma MA. Equistatin, a protease inhibitor from the sea anemone actinia equina, is composed of three structural and functional domains. Biochem Biophys Res Commun 2000; 269:732-6. [PMID: 10720485 DOI: 10.1006/bbrc.2000.2356] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A cDNA encoding a precursor of equistatin, a potent cysteine and aspartic proteinase inhibitor, was isolated from the sea anemone Actinia equina. The deduced amino acid sequence of a 199-amino-acid residue mature protein with 20 cysteine residues, forming three structurally similar thyroglobulin type-1 domains, is preceded by a typical eukaryotic signal peptide. The mature protein region and those coding for each of the domains were expressed in the periplasmic space of Escherichia coli, isolated, and characterized. The whole recombinant equistatin and its first domain, but not the second and third domains, inhibited the cysteine proteinase papain (K(i) 0.60 nM) comparably to natural equistatin. Preliminary results on inhibition of cathepsin D, supported by structural comparison, show that the second domain is likely to be involved in activity against aspartic proteinases.
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Affiliation(s)
- B Strukelj
- Department of Biochemistry and Molecular Biology, Jozef Stefan Institute, Jamova 39, Ljubljana, SI-1000, Slovenia.
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Volpicella M, Schipper A, Jongsma MA, Spoto N, Gallerani R, Ceci LR. Characterization of recombinant mustard trypsin inhibitor 2 (MTI2) expressed in Pichia pastoris. FEBS Lett 2000; 468:137-41. [PMID: 10692574 DOI: 10.1016/s0014-5793(00)01207-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The mustard trypsin inhibitor MTI2 was expressed as secretory protein in the yeast Pichia pastoris. In order to evaluate the influence of the C-terminal amino acids of the precursor form on the inhibitor activity, the C-terminal precursor and the mature protein were both expressed. A third His-tagged construct was also designed to compare alternative purification procedures. Proteins were efficiently expressed at levels of 40-160 mg/l in shake flasks. Equilibrium dissociation constants demonstrated that the mature protein was a stronger inhibitor of bovine beta-trypsin compared to the precursor and His-tagged forms (0.01 nM vs. 0.58 nM and 0.71 nM, respectively). The recombinant proteins were active inhibitors of Spodoptera exigua gut proteases.
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Affiliation(s)
- M Volpicella
- Dipartimento di Biochimica e Biologia Molecolare, Università di Bari, Via Amendola 165/A, 70126, Bari, Italy
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Gruden K, Strukelj B, Popovic T, Lenarcic B, Bevec T, Brzin J, Kregar I, Herzog-Velikonja J, Stiekema WJ, Bosch D, Jongsma MA. The cysteine protease activity of Colorado potato beetle (Leptinotarsa decemlineata Say) guts, which is insensitive to potato protease inhibitors, is inhibited by thyroglobulin type-1 domain inhibitors. Insect Biochem Mol Biol 1998; 28:549-560. [PMID: 9753766 DOI: 10.1016/s0965-1748(98)00051-4] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
High levels of protease inhibitors are induced in potato leaves by wounding. These inhibitors, when ingested by Colorado potato beetle (Leptinotarsa decemlineata Say) larvae, induce expression of specific proteolytic activities in the gut. Induced protease activities cannot be inhibited by potato inhibitors and thus enable the insects to overcome this defence mechanism of potato plants. The induced aminopeptidase and endoproteolytic activities both have the characteristics of cysteine proteases. Twenty-one protein inhibitors of different structural types have been examined for their ability to inhibit these activities in vitro. Members of the cystatin superfamily were found to be poor inhibitors of the induced endoproteolytic activities, except for the third domain of human kininogen, which was a fairly strong inhibitor (75% inhibition). The strongest inhibition (85%) of induced endoproteolytic activity was obtained using structurally different thyroglobulin type-1 domain-like inhibitors--equistatin and MHC class II-associated p41 invariant fragment. Experiments performed using three synthetic substrates for endoproteases gave similar results and indicate the existence of at least different endoproteolytic enzymes resistant to potato inhibitors. The induced aminopeptidase activity can be inhibited only by stefin family of inhibitors in cystatin superfamily. In in vivo experiments, Colorado potato beetle larvae fed on equistatin-coated potato leaves were strongly retarded in their growth and almost 50% died after 4 days. This demonstrated the potential of equistatin to protect crops from insect attack.
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Affiliation(s)
- K Gruden
- Department of Biochemistry and Molecular Biology, Jozef Stefan Institute, Ljubljana, Slovenia.
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Jongsma MA, Bakker PL, Peters J, Bosch D, Stiekema WJ. Adaptation of Spodoptera exigua larvae to plant proteinase inhibitors by induction of gut proteinase activity insensitive to inhibition. Proc Natl Acad Sci U S A 1995; 92:8041-5. [PMID: 7644535 PMCID: PMC41282 DOI: 10.1073/pnas.92.17.8041] [Citation(s) in RCA: 265] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Tobacco plants were transformed with a cDNA clone of chymotrypsin/trypsin-specific potato proteinase inhibitor II (PI2) under the control of a constitutive promoter. Although considerable levels of transgene expression could be demonstrated, the growth of Spodoptera exigua larvae fed with detached leaves of PI2-expressing plants was not affected. Analysis of the composition of tryptic gut activity demonstrated that only 18% of the proteinase activity of insects reared on these transgenic plants was sensitive to inhibition by PI2, whereas 78% was sensitive in insects reared on control plants. Larvae had compensated for this loss of tryptic activity by a 2.5-fold induction of new activity that was insensitive to inhibition by PI2. PI2-insensitive proteolytic activity was also induced in response to endogenous proteinase inhibitors of tobacco; therefore, induction of such proteinase activity may represent the mechanism by which insects that feed on plants overcome plant proteinase inhibitor defense.
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Affiliation(s)
- M A Jongsma
- Department of Molecular Biology, DLO-Centre for Plant Breeding and Reproduction Research (DLO-CPRO), Wageningen, The Netherlands
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van Engelen FA, Schouten A, Molthoff JW, Roosien J, Salinas J, Dirkse WG, Schots A, Bakker J, Gommers FJ, Jongsma MA. Coordinate expression of antibody subunit genes yields high levels of functional antibodies in roots of transgenic tobacco. Plant Mol Biol 1994; 26:1701-10. [PMID: 7858211 DOI: 10.1007/bf00019485] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
To explore the feasibility of employing antibodies to obtain disease resistance against plant root pathogens, we have studied the expression of genes encoding antibodies in roots of transgenic plants. A model monoclonal antibody was used that binds to a fungal cutinase. Heavy and light chain cDNAs were amplified by PCR, fused to a signal sequence for secretion and cloned behind CaMV 35S and TR2' promoters in a single T-DNA. The chimeric genes were cloned both in tandem and in a divergent orientation. The roots of tobacco plants transformed with these constructs produced antibodies that were able to bind antigen in an ELISA. Immunoblotting showed assembly to a full-size antibody. In addition, a F(ab')2-like fragment was observed, which is probably formed by proteolytic processing. Both antibody species were properly targeted to the apoplast, but the full-size antibody was partially retained by the wall of suspension cells. The construct with divergent promoters showed a better performance than the construct with promoters in tandem. It directed the accumulation of functional antibodies to a maximum of 1.1% of total soluble protein, with half of the plants having levels higher than 0.35%. The high efficiency of this construct probably results from coordinated and balanced expression of light and heavy chain genes, as evidenced by RNA blot hybridization.
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MESH Headings
- Amino Acid Sequence
- Antibodies, Fungal/biosynthesis
- Antibodies, Fungal/genetics
- Antibodies, Monoclonal/biosynthesis
- Antibodies, Monoclonal/genetics
- Antigen-Antibody Reactions
- Base Sequence
- Carboxylic Ester Hydrolases/immunology
- Cloning, Molecular
- Enzyme-Linked Immunosorbent Assay
- Genetic Engineering
- Immunoglobulin Heavy Chains/biosynthesis
- Immunoglobulin Heavy Chains/genetics
- Immunoglobulin Light Chains/biosynthesis
- Immunoglobulin Light Chains/genetics
- Molecular Sequence Data
- Mycoses/prevention & control
- Plant Diseases
- Plant Roots/immunology
- Plant Roots/metabolism
- Plants, Genetically Modified
- Plants, Toxic
- Promoter Regions, Genetic/genetics
- Protein Processing, Post-Translational
- Nicotiana/genetics
- Nicotiana/immunology
- Nicotiana/metabolism
- Transformation, Genetic
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Affiliation(s)
- F A van Engelen
- Centre for Plant Breeding and Reproduction Research (CPRO-DLO), Department of Molecular Biology, Wageningen, The Netherlands
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15
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Abstract
An improved, time efficient, visual assay for quantitative determination of proteinase inhibitor activity in protein extracts is reported. Proteinase inhibitor activity of mammalian, bacterial, and fungal serine proteinases can be quantified. The method relies on radial diffusion of proteinase inhibitor containing extracts from a central well through an agar gel containing a serine proteinase. After an incubation period the agar gel is stained via the diazo coupling of the beta-naphthol produced by the enzymatic hydrolysis of N-acetyl-DL-phenylalanine-beta-naphthyl-ester. Circular zones containing inhibitor-proteinase complexes remain colorless while the region containing only proteinase shows a bright pink-purple color. A reference curve relates the diameter of the colorless zone to the logarithm of the proteinase inhibitor concentration. The error in the estimation of a proteinase inhibitor quantity varying between 10 and 1000 pmol is 4-12%. The sensitivity of the assay is approximately 2-20 pmol of inhibited proteinase molecules depending on the inhibitor-proteinase complex assayed. The sensitivity of the assay can be enhanced 10-fold or more by dilution of the proteinase concentration in the agar and by a reduction of the agar thickness.
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Affiliation(s)
- M A Jongsma
- Department of Molecular Biology, DLO-Centre for Plant Breeding and Reproduction Research (CPRO-DLO), Wageningen, The Netherlands
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