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da Silva Gebara R, da Silva MS, Calixto SD, Simão TLBV, Zeraik AE, Lassounskaia E, Muzitano MF, Petretski JH, Gomes VM, de Oliveira Carvalho A. Antifungal, Antimycobacterial, Protease and α‒Amylase Inhibitory Activities of a Novel Serine Bifunctional Protease Inhibitor from Adenanthera pavonina L. Seeds. Probiotics Antimicrob Proteins 2023:10.1007/s12602-023-10194-z. [PMID: 38117407 DOI: 10.1007/s12602-023-10194-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/27/2023] [Indexed: 12/21/2023]
Abstract
Antifungal resistance poses a significant challenge to disease management, necessitating the development of novel drugs. Antimicrobial peptides offer potential solutions. This study focused on extraction and characterization of peptides from Adenanthera pavonina seeds with activity against Candida species, Mycobacterium tuberculosis, proteases, and α-amylases. Peptides were extracted in phosphate buffer and heated at 90°C for 10 min to create a peptide rich heated fraction (PRHF). After confirming antimicrobial activity and the presence of peptides, the PRHF underwent ion exchange chromatography, yielding retained and non-retained fractions. These fractions were evaluated for antimicrobial activity and cytotoxicity against murine macrophages. The least toxic and most active fraction underwent reversed-phase chromatography, resulting in ten fractions. These fractions were tested for peptides and antimicrobial activity. The most active fraction was rechromatographed on a reversed-phase column, resulting in two fractions that were assessed for antimicrobial activity. The most active fraction revealed a single band of approximately 6 kDa and was tested for inhibitory effects on proteases and α-amylases. Thermal stability experiments were conducted on the 6 kDa peptide at different temperatures followed by reassessment of antifungal activity and circular dichroism. The 6 kDa peptide inhibited yeasts, M. tuberculosis, human salivary and Tenebrio molitor larvae intestine α-amylases, and proteolytic activity from fungal extracts, and thus named ApPI. Remarkably, ApPI retained antifungal activity and conformation after heating and is primarily composed of α-helices. ApPI is a thermally stable serine protease/α-amylase inhibitor from A. pavonina seeds, offering promise as a foundational molecule for innovative therapeutic agents against fungal infections and tuberculosis.
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Affiliation(s)
- Rodrigo da Silva Gebara
- Laboratório de Fisiologia e Bioquímica de Microrganismos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, 28013-602, RJ, Brazil
| | - Marciele Souza da Silva
- Laboratório de Fisiologia e Bioquímica de Microrganismos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, 28013-602, RJ, Brazil
| | - Sanderson Dias Calixto
- Laboratório de Biologia do Reconhecer, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, 28013-602, RJ, Brazil
| | - Thatiana Lopes Biá Ventura Simão
- Laboratório de Biologia do Reconhecer, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, 28013-602, RJ, Brazil
| | - Ana Eliza Zeraik
- Laboratório de Química e Função de Proteinas e Peptídeos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, 28013-602, RJ, Brazil
| | - Elena Lassounskaia
- Laboratório de Biologia do Reconhecer, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, 28013-602, RJ, Brazil
| | - Michelle Frazão Muzitano
- Laboratório de Produtos Bioativos, Universidade Federal do Rio de Janeiro, Macaé, 27933-378, RJ, Brazil
| | - Jorge Hudson Petretski
- Laboratório de Biologia do Reconhecer, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, 28013-602, RJ, Brazil
| | - Valdirene Moreira Gomes
- Laboratório de Fisiologia e Bioquímica de Microrganismos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, 28013-602, RJ, Brazil
| | - André de Oliveira Carvalho
- Laboratório de Fisiologia e Bioquímica de Microrganismos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, 28013-602, RJ, Brazil.
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Brassica Genus Seeds: A Review on Phytochemical Screening and Pharmacological Properties. Molecules 2022; 27:molecules27186008. [PMID: 36144744 PMCID: PMC9500762 DOI: 10.3390/molecules27186008] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 09/11/2022] [Accepted: 09/12/2022] [Indexed: 11/23/2022] Open
Abstract
Traditionally, Brassica species are widely used in traditional medicine, human food, and animal feed. Recently, special attention has been dedicated to Brassica seeds as source of health-promoting phytochemicals. This review provides a summary of recent research on the Brassica seed phytochemistry, bioactivity, dietary importance, and toxicity by screening the major online scientific database sources and papers published in recent decades by Elsevier, Springer, and John Wiley. The search was conducted covering the period from January 1964 to July 2022. Phytochemically, polyphenols, glucosinolates, and their degradation products were the predominant secondary metabolites in seeds. Different extracts and their purified constituents from seeds of Brassica species have been found to possess a wide range of biological properties including antioxidant, anticancer, antimicrobial, anti-inflammatory, antidiabetic, and neuroprotective activities. These valuable functional properties of Brassica seeds are related to their richness in active compounds responsible for the prevention and treatment of various chronic diseases such as obesity, diabetes, cancer, and COVID-19. Currently, the potential properties of Brassica seeds and their components are the main focus of research, but their toxicity and health risks must also be accounted for.
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Mourão CBF, Brand GD, Fernandes JPC, Prates MV, Bloch C, Barbosa JARG, Freitas SM, Restano-Cassulini R, Possani LD, Schwartz EF. Head-to-Tail Cyclization after Interaction with Trypsin: A Scorpion Venom Peptide that Resembles Plant Cyclotides. J Med Chem 2020; 63:9500-9511. [PMID: 32787139 DOI: 10.1021/acs.jmedchem.0c00686] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Peptidase inhibitors (PIs) have been broadly studied due to their wide therapeutic potential for human diseases. A potent trypsin inhibitor from Tityus obscurus scorpion venom was characterized and named ToPI1, with 33 amino acid residues and three disulfide bonds. The X-ray structure of the ToPI1:trypsin complex, in association with the mass spectrometry data, indicate a sequential set of events: the complex formation with the inhibitor Lys32 in the trypsin S1 pocket, the inhibitor C-terminal residue Ser33 cleavage, and the cyclization of ToPI1 via a peptide bond between residues Ile1 and Lys32. Kinetic and thermodynamic characterization of the complex was obtained. ToPI1 shares no sequence similarity with other PIs characterized to date and is the first PI with CS-α/β motif described from animal venoms. In its cyclic form, it shares structural similarities with plant cyclotides that also inhibit trypsin. These results bring new insights for studies with venom compounds, PIs, and drug design.
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Affiliation(s)
- Caroline B F Mourão
- Neuropharma Lab, Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade de Brası́lia, Brasília-DF 70910-900, Brazil.,Instituto Federal de Brası́lia, Campus Ceilándia, Brası́lia-DF 72220-260, Brazil
| | - Guilherme D Brand
- Laboratório de Sı́ntese e Análise de Biomoléculas, LSAB, Instituto de Quı́mica, Universidade de Brası́lia, Brası́lia-DF 70910-900, Brazil
| | - João Paulo C Fernandes
- Laboratório de Biofı́sica Molecular, Departamento de Biologia Celular, Instituto de Ciências Biológicas, Universidade de Brası́lia, Brası́lia-DF 70910-900, Brazil
| | - Maura V Prates
- Laboratório de Espectrometria de Massa, EMBRAPA Recursos Genéticos e Biotecnologia, Brası́lia-DF 70770-917, Brazil
| | - Carlos Bloch
- Laboratório de Espectrometria de Massa, EMBRAPA Recursos Genéticos e Biotecnologia, Brası́lia-DF 70770-917, Brazil
| | - João Alexandre R G Barbosa
- Laboratório de Biofı́sica Molecular, Departamento de Biologia Celular, Instituto de Ciências Biológicas, Universidade de Brası́lia, Brası́lia-DF 70910-900, Brazil
| | - Sônia M Freitas
- Laboratório de Biofı́sica Molecular, Departamento de Biologia Celular, Instituto de Ciências Biológicas, Universidade de Brası́lia, Brası́lia-DF 70910-900, Brazil
| | - Rita Restano-Cassulini
- Instituto de Biotecnologı́a, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, Mexico
| | - Lourival D Possani
- Instituto de Biotecnologı́a, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, Mexico
| | - Elisabeth F Schwartz
- Neuropharma Lab, Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade de Brası́lia, Brasília-DF 70910-900, Brazil
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Joehnke MS, Rehder A, Sørensen S, Bjergegaard C, Sørensen JC, Markedal KE. In Vitro Digestibility of Rapeseed and Bovine Whey Protein Mixtures. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:711-719. [PMID: 29264921 DOI: 10.1021/acs.jafc.7b04681] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Partial replacement of animal protein sources with plant proteins is highly relevant for the food industry, but potential effects on protein digestibility need to be established. In this study, the in vitro protein digestibility (IVPD) of four protein sources and their mixtures (50:50 w/w ratio) was investigated using a transient pepsin hydrolysis (1 h) followed by pancreatin (1 h). The protein sources consisted of napin-rich rapeseed (Brassica napus L.) protein concentrates (RPCs; RP1, RP2) prepared in pilot scale and major bovine whey proteins (WPs; α-LA, alpha-lactalbumin; β-LG, beta-lactoglobulin). IVPD of individual protein sources was higher for WPs compared to RPCs. The RP2/β-LG mixture resulted in an unexpected high IVPD equivalent to β-LG protein alone. Protein mixtures containing RP1 showed a new IVPD response type due to the negative influence of a high trypsin inhibitor activity (TIA) level. Improved IVPD of RP1 alone and in protein mixtures was obtained by lowering the TIA level using dithiothreitol (DTT). These results showed that napin-rich protein products prepared by appropriate processing can be combined with specific WPs in mixtures to improve the IVPD.
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Affiliation(s)
- Marcel Skejovic Joehnke
- Department of Food Science, Faculty of Science, University of Copenhagen , Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark
| | - Alina Rehder
- Department of Food Science, Faculty of Science, University of Copenhagen , Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark
| | - Susanne Sørensen
- Department of Food Science, Faculty of Science, University of Copenhagen , Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark
| | - Charlotte Bjergegaard
- Department of Food Science, Faculty of Science, University of Copenhagen , Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark
| | - Jens Christian Sørensen
- Department of Food Science, Faculty of Science, University of Copenhagen , Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark
| | - Keld Ejdrup Markedal
- Department of Food Science, Faculty of Science, University of Copenhagen , Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark
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5
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Srikanth S, Chen Z. Plant Protease Inhibitors in Therapeutics-Focus on Cancer Therapy. Front Pharmacol 2016; 7:470. [PMID: 28008315 PMCID: PMC5143346 DOI: 10.3389/fphar.2016.00470] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 11/18/2016] [Indexed: 12/28/2022] Open
Abstract
Plants are known to have many secondary metabolites and phytochemical compounds which are highly explored at biochemical and molecular genetics level and exploited enormously in the human health care sector. However, there are other less explored small molecular weight proteins, which inhibit proteases/proteinases. Plants are good sources of protease inhibitors (PIs) which protect them against diseases, insects, pests, and herbivores. In the past, proteinaceous PIs were considered primarily as protein-degrading enzymes. Nevertheless, this view has significantly changed and PIs are now treated as very important signaling molecules in many biological activities such as inflammation, apoptosis, blood clotting and hormone processing. In recent years, PIs have been examined extensively as therapeutic agents, primarily to deal with various human cancers. Interestingly, many plant-based PIs are also found to be effective against cardiovascular diseases, osteoporosis, inflammatory diseases and neurological disorders. Several plant PIs are under further evaluation in in vitro clinical trials. Among all types of PIs, Bowman-Birk inhibitors (BBI) have been studied extensively in the treatment of many diseases, especially in the field of cancer prevention. So far, crops such as beans, potatoes, barley, squash, millet, wheat, buckwheat, groundnut, chickpea, pigeonpea, corn, and pineapple have been identified as good sources of PIs. The PI content of such foods has a significant influence on human health disorders, particularly in the regions where people mostly depend on these kind of foods. These natural PIs vary in concentration, protease specificity, heat stability, and sometimes several PIs may be present in the same species or tissue. However, it is important to carry out individual studies to identify the potential effects of each PI on human health. PIs in plants make them incredible sources to determine novel PIs with specific pharmacological and therapeutic effects due to their peculiarity and superabundance.
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Affiliation(s)
| | - Zhong Chen
- Natural Sciences and Science Education, National Institute of Education, Nanyang Technological UniversitySingapore, Singapore
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6
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Leboffe L, Angelini R, Menegatti E, Polticelli F, Ascenzi P. Different disulfide bridge connectivity drives alternative folds in highly homologous Brassicaceae trypsin inhibitors. IUBMB Life 2015; 67:966-70. [PMID: 26545561 DOI: 10.1002/iub.1447] [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: 07/27/2015] [Accepted: 10/08/2015] [Indexed: 11/11/2022]
Abstract
Low-molecular-mass trypsin inhibitors from Arabidopsis thaliana, Brassica napus var. oleifera, and Sinapis alba L. (ATTI, RTI, and MTI, respectively) display more than 69% amino acid sequence identity. Among others, the amino acid sequence Cys-Ala-Pro-Arg-Ile building up the inhibitor reactive site, and the eight Cys residues forming four disulfide bridges are conserved. However, the disulfide bridge connectivity of RTI and MTI (C1-C3, C2-C4, C5-C6, and C7-C8) is different from that of ATTI Cys (C1-C8, C2-C5, C3-C6, and C4-C7). Despite the different disulfide bridge connectivity, the reactive site loop of ATTI, RTI, and MTI is solvent exposed permitting trypsin recognition. Structural considerations here reported suggest that proteins showing high amino acid sequence identity and common functional properties could display different three-dimensional structures. This may reflect high inhibitor plasticity in relation to plant-pathogen interactions, plant tissue development as well as the different redox potential of cell compartments.
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Affiliation(s)
- Loris Leboffe
- Laboratorio Interdipartimentale di Microscopia Elettronica, Università Roma Tre, Roma, Italy
| | | | - Enea Menegatti
- Dipartimento di Scienze Chimiche e Farmaceutiche, Università di Ferrara, Ferrara, Italy
| | - Fabio Polticelli
- Dipartimento di Scienze, Università Roma Tre, Roma, Italy.,Istituto Nazionale di Fisica Nucleare, Sezione Università Roma Tre, Roma, Italy
| | - Paolo Ascenzi
- Laboratorio Interdipartimentale di Microscopia Elettronica, Università Roma Tre, Roma, Italy
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7
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Kumar R, Bhardwaj U, Kumar P, Mazumdar-Leighton S. Midgut serine proteases and alternative host plant utilization in Pieris brassicae L. Front Physiol 2015; 6:95. [PMID: 25873901 PMCID: PMC4379908 DOI: 10.3389/fphys.2015.00095] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 03/12/2015] [Indexed: 11/13/2022] Open
Abstract
Pieris brassicae L. is a serious pest of cultivated crucifers in several parts of the world. Larvae of P. brassicae also feed prolifically on garden nasturtium (Tropaeolum majus L., of the family Tropaeolaceae). Proteolytic digestion was studied in larvae feeding on multiple hosts. Fourth instars were collected from cauliflower fields before transfer onto detached, aerial tissues of selected host plants in the lab. Variable levels of midgut proteases were detected in larvae fed on different hosts using protein substrates (casein and recombinant RBCL cloned from cauliflower) and diagnostic, synthetic substrates. Qualitative changes in midgut trypsin activities and quantitative changes in midgut chymotrypsin activities were implicated in physiological adaptation of larvae transferred to T. majus. Midgut proteolytic activities were inhibited to different extents by serine protease inhibitors, including putative trypsin inhibitors isolated from herbivore-attacked and herbivore-free leaves of cauliflower (CfTI) and T. majus (TpTI). Transfer of larvae to T. majus significantly influenced feeding parameters but not necessarily when transferred to different tissues of the same host. Results obtained are relevant for devising sustainable pest management strategies, including transgenic approaches using genes encoding plant protease inhibitors.
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Affiliation(s)
- Rakesh Kumar
- Insect-Plant Interactions Group, Department of Botany, Delhi University Delhi, India
| | - Usha Bhardwaj
- Insect-Plant Interactions Group, Department of Botany, Delhi University Delhi, India
| | - Pawan Kumar
- Insect-Plant Interactions Group, Department of Botany, Delhi University Delhi, India
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8
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F. Ribeiro SF, S. Fernandes KV, Santos IS, Taveira GB, Carvalho AO, Lopes JLS, Beltramini LM, Rodrigues R, Vasconcelos IM, Da Cunha M, Souza-Filho GA, Gomes VM. New small proteinase inhibitors fromCapsicum annuumseeds: Characterization, stability, spectroscopic analysis and a cDNA cloning. Biopolymers 2013; 100:132-40. [DOI: 10.1002/bip.22172] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 10/01/2012] [Accepted: 10/08/2012] [Indexed: 11/12/2022]
Affiliation(s)
- Suzanna F. F. Ribeiro
- Centro de Biociências e Biotecnologia; Universidade Estadual do Norte Fluminense; Campos dos Goytacazes; 28015-602; Rio de Janeiro; Brazil
| | - Kátia V. S. Fernandes
- Centro de Biociências e Biotecnologia; Universidade Estadual do Norte Fluminense; Campos dos Goytacazes; 28015-602; Rio de Janeiro; Brazil
| | - Izabela S. Santos
- Centro de Biociências e Biotecnologia; Universidade Estadual do Norte Fluminense; Campos dos Goytacazes; 28015-602; Rio de Janeiro; Brazil
| | - Gabriel B. Taveira
- Centro de Biociências e Biotecnologia; Universidade Estadual do Norte Fluminense; Campos dos Goytacazes; 28015-602; Rio de Janeiro; Brazil
| | - André O. Carvalho
- Centro de Biociências e Biotecnologia; Universidade Estadual do Norte Fluminense; Campos dos Goytacazes; 28015-602; Rio de Janeiro; Brazil
| | - José Luiz S. Lopes
- Instituto de Física de São Carlos; Grupo de Biofísica Molecular; Universidade de São Paulo; 13560-970; São Paulo; Brazil
| | - Leila M. Beltramini
- Instituto de Física de São Carlos; Grupo de Biofísica Molecular; Universidade de São Paulo; 13560-970; São Paulo; Brazil
| | - Rosana Rodrigues
- Centro de Ciências e Tecnologias Agropecuárias; Universidade Estadual do Norte Fluminense; Campos dos Goytacazes; 28015-602; Rio de Janeiro; Brazil
| | - Ilka M. Vasconcelos
- Departamento de Bioquímica e Biologia Molecular; Universidade Federal do Ceará; Fortaleza; Ceará; Brazil
| | - Maura Da Cunha
- Centro de Biociências e Biotecnologia; Universidade Estadual do Norte Fluminense; Campos dos Goytacazes; 28015-602; Rio de Janeiro; Brazil
| | - Gonçalo A. Souza-Filho
- Centro de Biociências e Biotecnologia; Universidade Estadual do Norte Fluminense; Campos dos Goytacazes; 28015-602; Rio de Janeiro; Brazil
| | - Valdirene M. Gomes
- Centro de Biociências e Biotecnologia; Universidade Estadual do Norte Fluminense; Campos dos Goytacazes; 28015-602; Rio de Janeiro; Brazil
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Wanasundara JPD. Proteins ofBrassicaceaeOilseeds and their Potential as a Plant Protein Source. Crit Rev Food Sci Nutr 2011; 51:635-77. [DOI: 10.1080/10408391003749942] [Citation(s) in RCA: 110] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Bhattacharyya A, Rai S, Babu CR. A trypsin and chymotrypsin inhibitor from Caesalpinia bonduc seeds: isolation, partial characterization and insecticidal properties. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2007; 45:169-77. [PMID: 17400464 DOI: 10.1016/j.plaphy.2007.02.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2006] [Accepted: 02/01/2007] [Indexed: 05/14/2023]
Abstract
Evolution of proteinase inhibitor diversity in leguminous plants of tropical rainforests is under immense pressure from the regular upregulation of proteolytic machinery of their pests. The present study illustrates the isolation and bioinsecticidal potency of a serine proteinase inhibitor from the seeds of Caesalpinia bonduc (CbTI), inhabiting Great Nicobar Island, India. Following initial fractionation by ammonium sulfate precipitation, CbTI was purified to homogeneity by ion exchange, gel filtration and trypsin affinity chromatography. SDS-PAGE of gel filtrated CbTI showed a couple of proteins CbTI-1 ( approximately 16kDa) and CbTI-2 (20kDa) under non-reducing conditions, which subsequent to trypsin affinity chromatography yielded only CbTI-2. Both Native PAGE as well as iso-electric focusing showed 2 iso-inhibitors of CbTI-2 (pI values of 5.35 and 4.6). CbTI exhibited tolerance to extremes of temperatures (0-60 degrees C) and pH (1-12). A 1:1 stoichiometric ratio was noted during CbTI-2-trypsin complex formation, which was absent on binding with chymotrypsin. Further, SDS-PAGE analysis also showed that CbTI-1 has affinity only towards chymotrypsin, whereas both trypsin and chymotrypsin formed complexes with CbTI-2. Dixon plot analysis of CbTI-2 yielded inhibition constants (K(i)) of 2.75 x 10(-10)M and 0.95 x 10(-10)M against trypsin and chymotrypsin activity respectively. Preliminary investigations on the toxicological nature of CbTI revealed it to be a promising bioinsecticidal candidate.
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11
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Bhattacharyya A, Mazumdar S, Leighton SM, Babu CR. A Kunitz proteinase inhibitor from Archidendron ellipticum seeds: purification, characterization, and kinetic properties. PHYTOCHEMISTRY 2006; 67:232-41. [PMID: 16376957 DOI: 10.1016/j.phytochem.2005.11.010] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2005] [Revised: 11/07/2005] [Accepted: 11/09/2005] [Indexed: 05/05/2023]
Abstract
Leguminous plants in the tropical rainforests are a rich source of proteinase inhibitors and this work illustrates isolation of a serine proteinase inhibitor from the seeds of Archidendron ellipticum (AeTI), inhabiting Great Nicobar Island, India. AeTI was purified to homogeneity by acetone and ammonium sulfate fractionation, and ion exchange, size exclusion and reverse phase chromatography (HPLC). SDS-PAGE of AeTI revealed that it is constituted by two polypeptide chains (alpha-chain, M(r) 15,000 and beta-chain, M(r) 5000), the molecular weight being approximately 20 kDa. N-terminal sequence showed high homology with other serine proteinase inhibitors belonging to the Mimosoideae subfamily. Both Native-PAGE as well as isoelectric focussing showed four isoinhibitors (pI values of 4.1, 4.55, 5.27 and 5.65). Inhibitory activity of AeTI remained unchanged over a wide range of temperatures (0-60 degrees C) and pH (1-10). The protein inhibited trypsin in the stoichiometric ratio of 1:1, but lacked similar stoichiometry against chymotrypsin. Also, AeTI-trypsin complex was stable to SDS unlike the SDS unstable AeTI-chymotrypsin complex. AeTI, which possessed inhibition constants (K(i)) of 2.46 x 10(-10) and 0.5 x 10(-10)M against trypsin and chymotrypsin activity, respectively, retained over 70% of inhibitory activity after being stored at -20 degrees C for more than a year. Initial studies on the insecticidal properties of AeTI indicate it to be a very potent insect anti-feedant.
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Affiliation(s)
- Arindam Bhattacharyya
- Centre for Environmental Management of Degraded Ecosystems, University of Delhi, Delhi 110007, India.
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De Leo F, Volpicella M, Sciancalepore M, Gallerani R, Ceci LR. One of the three proteinase inhibitor genes newly identified in theBrassica napusgenome codes for an inhibitor of glutamyl endopeptidase. FEBS Lett 2006; 580:948-54. [PMID: 16438970 DOI: 10.1016/j.febslet.2006.01.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2005] [Accepted: 01/09/2006] [Indexed: 10/25/2022]
Abstract
Three proteinase inhibitor genes have been identified in the rapeseed (Brassica napus) genome. They are highly homologous to other genes of the mustard inhibitor (MSI) family of proteinase inhibitors characteristic of Cruciferae. In germinating seeds, only the transcript of one gene, coding for a trypsin inhibitor, is detectable by Northern analysis. The other two genes are transcribed at basal levels detectable only by reverse transcription PCR. One of the other two genes (rti-2) encodes a polypeptide with a glutamic residue in the P1 position, characteristic of glutamyl proteinase inhibitors. The recombinant RTI-2 protein strongly inhibits (Ki=44 nM) a glutamyl proteinase from Streptomyces griseus.
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Affiliation(s)
- Francesca De Leo
- Institute of Biomembranes and Bioenergetic, Italian National Research Council, CNR, Via Amendola, 165/A, 70126 Bari, Italy
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14
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Clauss MJ, Mitchell-Olds T. Functional divergence in tandemly duplicated Arabidopsis thaliana trypsin inhibitor genes. Genetics 2004; 166:1419-36. [PMID: 15082560 PMCID: PMC1470761 DOI: 10.1534/genetics.166.3.1419] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
In multigene families, variation among loci and alleles can contribute to trait evolution. We explored patterns of functional and genetic variation in six duplicated Arabidopsis thaliana trypsin inhibitor (ATTI) loci. We demonstrate significant variation in constitutive and herbivore-induced transcription among ATTI loci that show, on average, 65% sequence divergence. Significant variation in ATTI expression was also found between two molecularly defined haplotype classes. Population genetic analyses for 17 accessions of A. thaliana showed that six ATTI loci arranged in tandem within 10 kb varied 10-fold in nucleotide diversity, from 0.0009 to 0.0110, and identified a minimum of six recombination events throughout the tandem array. We observed a significant peak in nucleotide and indel polymorphism spanning ATTI loci in the interior of the array, due primarily to divergence between the two haplotype classes. Significant deviation from the neutral equilibrium model for individual genes was interpreted within the context of intergene linkage disequilibrium and correlated patterns of functional differentiation. In contrast to the outcrosser Arabidopsis lyrata for which recombination is observed even within ATTI loci, our data suggest that response to selection was slowed in the inbreeding, annual A. thaliana because of interference among functionally divergent ATTI loci.
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Affiliation(s)
- M J Clauss
- Department of Genetics and Evolution, Max Planck Institute of Chemical Ecology, 07745 Jena, Germany.
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15
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Haq SK, Atif SM, Khan RH. Protein proteinase inhibitor genes in combat against insects, pests, and pathogens: natural and engineered phytoprotection. Arch Biochem Biophys 2004; 431:145-59. [PMID: 15464737 DOI: 10.1016/j.abb.2004.07.022] [Citation(s) in RCA: 209] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2004] [Revised: 07/20/2004] [Indexed: 11/24/2022]
Abstract
The continual need to increase food production necessitates the development and application of novel biotechnologies to enable the provision of improved crop varieties in a timely and cost-effective way. A milestone in this field was the introduction of Bacillus thuringiensis (Bt) entomotoxic proteins into plants. Despite the success of this technology, there is need for development of alternative strategies of phytoprotection. Biotechnology offers sustainable solutions to the problem of pests, pathogens, and plant parasitic nematodes in the form of other insecticidal protein genes. A variety of genes, besides (Bt) toxins that are now available for genetic engineering for pest resistance are genes for vegetative insecticidal proteins, proteinase inhibitors, alpha-amylase inhibitors, and plant lectins. This review presents a comprehensive summary of research efforts that focus on the potential use and advantages of using proteinase inhibitor genes to engineer insect- and pest-resistance. Crop protection by means of PI genes is an important component of Integrated Pest Management programmes.
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Affiliation(s)
- Soghra Khatun Haq
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202 002, India
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16
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Clauss MJ, Mitchell-Olds T. Population genetics of tandem trypsin inhibitor genes in Arabidopsis species with contrasting ecology and life history. Mol Ecol 2003; 12:1287-99. [PMID: 12694291 DOI: 10.1046/j.1365-294x.2003.01832.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Duplicated genes are important in the evolution and ecology of plant-defences because herbivore and pathogen attack can be countered via functional diversification at two levels: among duplicated loci and within loci. We explore molecular sequence variation for two members of a defence-related gene family, Arabidopsis thaliana trypsin inhibitors (ATTI), in A. thaliana and a closely related species, A. lyrata subspp. petraea. A worldwide sample of the inbreeding annual A. thaliana had less genetic variation at two ATTI loci (piTOTAL <or= 0.0006) than observed previously at other functional loci. A significant excess of high frequency derived alleles in the signal sequence and 5' UTR of ATTI2 was consistent with a model of positive selection. However, demographic processes such as population subdivision and expansion, both likely to have occurred in A. thaliana during the last 10 000 years, can also give rise to similar deviations from neutrality. A single population of A. lyrata subspp. petraea in Germany had up to an order of magnitude more standing genetic variation at ATTI loci than the species-wide sample of A. thaliana. Although the level of variability for ATTI1 and ATTI2 within this single population was similar to, or even greater than, observed species-wide diversity for other loci in A. lyrata, there was little evidence to reject an equilibrium neutral model. A spatially explicit sample of 87 A. lyrata subspp. petraea individuals detected outbreeding (FIS = -0.16; FIT = -0.15) but little population subdivision (FST = 0.006) in this self-incompatible perennial herb. Genetic differences between Arabidopsis species were consistent with, but not fully explained by, divergence in ecology and life history. Diversification appears to have occurred in different functional domains for the tandemly duplicated ATTI1 and ATTI2 genes; the majority of fixed replacements in ATTI1 surround the enzyme binding site of the mature protein, whereas in ATTI2 most functional evolutionary change is located in the signal peptide. This pattern is consistent with a hypothesis of subfunctionalization in trypsin inhibitory function.
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Affiliation(s)
- M J Clauss
- Department of Genetics and Evolution, Max Planck Institute of Chemical Ecology, Beutenberg Campus, Winzerlaer Str. 10, 07745 Jena, Germany.
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Trovato M, Casavola EC, Maras B, Schininà ME, Costantino P, Ascenzi P. Protein minimization: characterization of the synthetic cyclic dodecapeptide corresponding to the reactive site region of the oil rape trypsin inhibitor type-III. Biochem Biophys Res Commun 2003; 302:311-5. [PMID: 12604347 DOI: 10.1016/s0006-291x(03)00181-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The design of minimal units required for enzyme inhibition is a major field of interest in structural biology and biotechnology. The successful design of the cyclic dodecapeptide corresponding to the Phe17-Val28 reactive site amino acid sequence of the low-molecular-mass trypsin inhibitor RTI-III from Brassica napus (micro-RTI-III) and of the recombinant murine dihydrofolate reductase-(DHFR-)micro-RTI-III fusion protein (DHFR-micro-RTI-III) is reported here. Micro-RTI-III was synthesized using a stepwise solid-phase approach based on the standard Fmoc chemistry, purified by RP-HPLC, and oxidatively refolded. DHFR-micro-RTI-III was expressed in Escherichia coli, purified by metal-chelate affinity chromatography, and oxidatively refolded. The affinity of micro-RTI-III for bovine trypsin (K(d)=1.6x10(-9)M) is similar to that determined for DHFR-micro-RTI-III (K(d)=6.3x10(-10)M) and native RTI-III (K(d)=2.9x10(-10)M), at pH 8.2 and 22.0 degrees C. Remarkably, micro-RTI-III protects the DHFR domain of DHFR-micro-RTI-III from trypsin digestion. Micro-RTI-III is a new minimal trypsin inhibitor and may be regarded as a tool in protein structure-function studies and for developing multifunctional and multidomain proteinase inhibitors.
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Affiliation(s)
- Maurizio Trovato
- Dipartimento di Genetica e Biologia Molecolare Charles Darwin, Università di Roma La Sapienza, Italy
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18
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Zhao Q, Chae YK, Markley JL. NMR solution structure of ATTp, an Arabidopsis thaliana trypsin inhibitor. Biochemistry 2002; 41:12284-96. [PMID: 12369816 DOI: 10.1021/bi025702a] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The three-dimensional structure of the precursor form of the Arabidopsis thaliana trypsin inhibitor (ATT(p), GenBank entry Z46816), a 68-residue (approximately 7.5 kDa) rapeseed class proteinase inhibitor, has been determined in solution at pH 5.0 and 25 degrees C by multinuclear magnetic resonance spectroscopy. The protein contains one alpha-helix and two strands of antiparallel beta-sheet, with a type IV beta-turn connecting the two strands. The alpha-helix and the inhibitory loop are connected to the beta-sheet through three disulfide bridges; a fourth disulfide bridge connects the N- and C-termini. The overall structural topology of ATT(p) is similar to those of the sweet tasting protein brazzein (rmsd of 3.0 A) and the antifungal protein Rs-Afp1 [a knottin protein from radish (Raphanus sativus), rmsd of 2.7 A]. The precursor segment in ATT(p) is disordered, as visualized by the final 20-conformer ensemble and as confirmed by (15)N heteronuclear NOE analysis. The overall fold of ATT(p) is distinct from those of other classes of serine proteinase inhibitors except in the inhibitor loop; therefore, it represents a new inhibitor fold.
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Affiliation(s)
- Qin Zhao
- Department of Biochemistry, University of Wisconsin-Madison, 53706, USA
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19
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De Leo F, Bonadé-Bottino M, Ceci LR, Gallerani R, Jouanin L. Effects of a mustard trypsin inhibitor expressed in different plants on three lepidopteran pests. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2001; 31:593-602. [PMID: 11267898 DOI: 10.1016/s0965-1748(00)00164-8] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The effects of mustard trypsin inhibitor MTI-2 expressed at different levels in transgenic tobacco, arabidopsis and oilseed rape lines have been evaluated against three different lepidopteran insect pests. 1. Plutella xylostella (L.) larvae were the most sensitive to the ingestion of MTI-2. The inhibitor expressed at high levels in arabidopsis plants caused rapid and complete mortality. High mortality and significantly delayed larval development were also detectable in oilseed rape expressing MTI-2 at lower levels. 2. Mamestra brassicae (L.) larvae were sensitive only at high MTI-2 expression level, as obtained in transgenic tobacco and arabidopsis, whereas no effects were observed for larvae fed on plants showing relatively low expression levels such as those of oilseed rape lines. 3. Feeding bioassays with Spodoptera littoralis (Boisduval) larvae were carried out using the same oilseed rape lines, showing that at these low expression levels no mortality was observed although a delay in larval development did occur. The levels of insect gut proteolytic activities of the larvae still alive at the end of a 7 day feeding bioassay were usually higher than in the controls, but no new proteinases were expressed in any case. The combined results described in this paper demonstrate altogether the relevance of a case-by-case analysis [target insects and proteinase inhibitor (PI) level of expression in planta] in a PI-based strategy for plant protection.
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Affiliation(s)
- F De Leo
- Laboratoire de Biologie Cellulaire, Institut National de la Recherche Agronomique, Route de Saint Cyr, F-78026 Versailles Cedex, France.
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20
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Lorenc-Kubis I, Kowalska J, Pochroń B, Zuzło A, Wilusz T. Isolation and amino acid sequence of a serine proteinase inhibitor from common flax (Linum usitatissimum) seeds. Chembiochem 2001; 2:45-51. [PMID: 11828426 DOI: 10.1002/1439-7633(20010105)2:1<45::aid-cbic45>3.0.co;2-%23] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
LUTI (Linum usitatissimum trypsin inhibitor), a member of the potato inhibitor I family, has been isolated from seeds of flax by ethanol fractionation, ion exchange chromatography on CM-Sephadex C-25, affinity purification on immobilized methylchymotrypsin (alpha-chymotrypsin in which His57 has been converted to 3-methylhistidine) in the presence of 5M NaCl, and finally by reversed-phase HPLC. The 7655 Da inhibitor consists of a single polypeptide chain of 69 residues with one disulfide bridge. The molecule is acetylated at the N terminus. Its primary structure has been determined after limited proteolysis of the native molecule with trypsin at the reactive site, cleavage with cyanogen bromide or arginyl endopeptidase (Arg-gingipain), and alcoholytic deacetylation of the N-terminally blocked serine. The association constants (K(a)) of LUTI with bovine beta-trypsin and alpha-chymotrypsin are 3.58x10(10) M(-1) and 5.02x10(5) M(-1), respectively. High NaCl concentration (3M) increased the association constant of LUTI with alpha-chymotrypsin to 6.64x10(7) M(-1). To our knowledge, LUTI is the first serine-proteinase-type inhibitor isolated from a plant of the Linaceae family.
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Affiliation(s)
- I Lorenc-Kubis
- Institute of Biochemistry and Molecular Biology, University of Wrocław, Tamka 2, 50-137 Wrocław, Poland
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21
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Lorenc‐Kubis I, Kowalska J, Pochroń B, Żużło A, Wilusz T. Isolation and Amino Acid Sequence of a Serine Proteinase Inhibitor from Common Flax (
Linum usitatissimum
) Seeds. Chembiochem 2001. [DOI: 10.1002/1439-7633(20010105)2:1<45::aid-cbic45>3.0.co;2-#] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Irena Lorenc‐Kubis
- Institute of Biochemistry and Molecular Biology University of Wrocław Tamka 2, 50‐137 Wrocław (Poland) Fax: (+48) 71‐3752‐608
| | - Jolanta Kowalska
- Institute of Biochemistry and Molecular Biology University of Wrocław Tamka 2, 50‐137 Wrocław (Poland) Fax: (+48) 71‐3752‐608
| | - Bogusława Pochroń
- Institute of Biochemistry and Molecular Biology University of Wrocław Tamka 2, 50‐137 Wrocław (Poland) Fax: (+48) 71‐3752‐608
| | - Aneta Żużło
- Institute of Biochemistry and Molecular Biology University of Wrocław Tamka 2, 50‐137 Wrocław (Poland) Fax: (+48) 71‐3752‐608
| | - Tadeusz Wilusz
- Institute of Biochemistry and Molecular Biology University of Wrocław Tamka 2, 50‐137 Wrocław (Poland) Fax: (+48) 71‐3752‐608
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22
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Ruoppolo M, Amoresano A, Pucci P, Pascarella S, Polticelli F, Trovato M, Menegatti E, Ascenzi P. Characterization of five new low-molecular-mass trypsin inhibitors from white mustard (Sinapis alba L.) seed. EUROPEAN JOURNAL OF BIOCHEMISTRY 2000; 267:6486-92. [PMID: 11029593 DOI: 10.1046/j.1432-1327.2000.01741.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Five new low-molecular-mass trypsin inhibitors belonging to the RTI/MTI-2 family were identified from white mustard (Sinapis alba L. ; MTI-2) seed. Purified MTI-2 consisted of a peptide mixture, displaying Ile or Arg at position 43, Trp or kynurenine (Kyn) at position 44, and C-terminal ragged ends. The occurrence of Ile or Arg at position 43 suggested that MTI-2 inhibitors originated from different genes. The presence of 5-oxo-proline (pyroglutamic acid; 5-oxoPro1) and Kyn44 reflected post-translational processing of the serine proteinase inhibitor. MTI-2 showed approximately 70% amino-acid identity with low-molecular-mass trypsin inhibitors isolated from oil rape (Brassica napus var. oleifera; RTI-III) seed and with serine proteinase inhibitors mapped in Arabidopsis thaliana chromosome II (ATTI). Furthermore, MTI-2 was homologous to brazzein, the sweet-tasting protein from Pentadiplandra brazzeana Baillon fruit ( approximately 30% amino-acid identity). Although snake-venom toxins showed a low amino-acid identity (< 20%) with MTI-2, RTI-III, and ATTI, some structurally relevant residues were conserved. The disulfide bridge pattern of MTI-2 (Cys5-Cys27, Cys18-Cys31, Cys42-Cys52, and Cys54-Cys57) corresponded to that of RTI-III and of snake-venom toxins, being different from that of brazzein. Therefore, protein similarity might be attributable to the three-dimensional arrangement rather than to the amino-acid sequence. Values of Ka for MTI-2 binding to bovine beta-trypsin (trypsin) and bovine alpha-chymotrypsin were 6.3 x 109 M-1 and 2.0 x 106 M-1, respectively, at pH 8.0 and 21.0 degrees C. Moreover, values of kon for MTI-2 binding to trypsin and of koff for the dissociation of the serine proteinase:inhibitor complex were 5.6 x 105 M-1.s-1 and 8.9 x 10-5 M-1.s-1, respectively, at pH 8.0 and 21.0 degrees C. Despite the heterogeneity of the purified inhibitor peptide mixture, the inhibition properties of the different MTI-2 inhibitors were indistinguishable.
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Affiliation(s)
- M Ruoppolo
- Dipartimento di Chimica, Università di Salerno, Italy
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23
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Trovato M, Maras B, Polticelli F, Costantino P, Ascenzi P. A chimeric mini-trypsin inhibitor derived from the oil rape proteinase inhibitor type III. Biochem Biophys Res Commun 2000; 275:817-20. [PMID: 10973804 DOI: 10.1006/bbrc.2000.3376] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The design of chimeric proteins is a major field of interest in structural biology and biotechnology. The successful design of the chimeric protein composed by the minimized reactive site domain of the low-molecular-mass trypsin inhibitor from Brassica napus (var. oleifera) seed (Ser3-Lys35; mini-RTI-III) and murine dihydrofolate reductase (DHFR) is reported here. The DHFR-mini-RTI-III chimeric protein was expressed in Escherichia coli, purified by metal-chelate affinity chromatography and oxidatively refolded. The affinity of the purified and refolded DHFR-mini-RTI-III for bovine trypsin (K = 5.0 x 10(-10) M) was closely similar to that determined for native RTI-III (K = 2.9 x 10(-10) M), at pH 8.2 and 22.0 degrees C. DHFR-mini-RTI-III may be regarded as a tool in structure-function studies and for developing multifunctional and multidomain proteinase inhibitors.
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Affiliation(s)
- M Trovato
- Dipartimento di Genetica e Biologia Molecolare 'Charles Darwin', Università di Roma 'La Sapienza', Piazzale A. Moro 5, Rome, I-00185, Italy
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Assadi-Porter FM, Aceti DJ, Markley JL. Sweetness determinant sites of brazzein, a small, heat-stable, sweet-tasting protein. Arch Biochem Biophys 2000; 376:259-65. [PMID: 10775411 DOI: 10.1006/abbi.2000.1726] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Brazzein, originally isolated from the fruit of the African plant Pentadiplandra brazzeana Baillon, is the smallest, most heat-stable and pH-stable member of the set of proteins known to have intrinsic sweetness. These properties make brazzein an ideal system for investigating the chemical and structural requirements of a sweet-tasting protein. We have used the three-dimensional structure of the protein (J. E. Caldwell et al. (1998) Nat. Struct. Biol. 5, 427-431) as a guide in designing 15 synthetic genes in expression constructs aimed at delineating the sweetness determinants of brazzein. Protein was produced heterologously in Escherichia coli, isolated, and purified as described in the companion paper (Assadi-Porter, F. M., Aceti, D., Cheng, H., and Markley, J. L., this issue). Analysis by one-dimensional (1)H NMR spectroscopy indicated that all but one of these variants had folded properly under the conditions used. A taste panel compared the gustatory properties of solutions of these proteins to those of sucrose and brazzein isolated from fruit. Of the 14 mutations in the des-pGlu1-brazzein background, four exhibited almost no sweetness, six had significantly reduced sweetness, two had taste properties equivalent to des-pGlu1-brazzein (two times as sweet as the major form of brazzein isolated from fruit which contains pGlu1), and two were about twice as sweet as des-pGlu1-brazzein. Overall, the results suggest that two regions of the protein are critical for the sweetness of brazzein: a region that includes the N- and C-termini of the protein, which are located close to one another, and a region that includes the flexible loop around Arg43.
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Affiliation(s)
- F M Assadi-Porter
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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25
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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] [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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