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Huang B, Liang Y, Pan H, Xie L, Jiang T, Jiang T. Hemolytic and cytotoxic activity from cultures of Aureococcus anophagefferens-a causative species of brown tides in the north-western Bohai Sea, China. Chemosphere 2020; 247:125819. [PMID: 31927184 DOI: 10.1016/j.chemosphere.2020.125819] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [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: 08/27/2019] [Revised: 12/20/2019] [Accepted: 01/02/2020] [Indexed: 06/10/2023]
Abstract
Brown tides were first observed in 2009 in the north-western Bohai Sea (Qinhuangdao sea area), China, and blooms have occurred at different scales in late spring every year since then. Although the detrimental effects on marine organisms of the causative phytoplankton species Aureococcus anophagefferens have been extensively studied, the mechanism remains poorly understood. We used erythrocytes and adrenal gland chromaffin tumor cells (PC12) to explore the hemolytic activity and cytotoxicity, respectively, of chloroform and methanol extracts of cultured A. anophagefferens isolated from the north-western Bohai Sea area. The methanol extracts showed no hemolytic or cytotoxic activity. Chloroform extracts had a potent hemolytic effect on rabbit erythrocytes; thin layer chromatography (TLC) indicated that the hemolysin was a kind of glycolipid compound. Erythrocyte lysis assay showed that erythrocytes of sea bream were sensitive to the hemolysin, whereas those of human and chicken erythrocytes were insensitive. The hemolytic effects were elevated as temperatures rose from 4 °C to 37 °C. Hemolytic blocking experiments showed that sphingomyelin and d-xylose can inhibit hemolysis significantly, while osmotic protectants with different hydrated molecular diameters had no inhibition, and the hemolysins had no obvious phospholipase activity. The chloroform extracts of A. anophagefferens had significant inhibitory effects on the viability of PC12 cells, and can induce efflux of lactic dehydrogenase (LDH) of PC12 cells and lead to their necrosis.
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Affiliation(s)
- Baiqiang Huang
- Research Center of Harmful Algae & Marine Biology, Jinan University, Guangzhou, 510632, China
| | - Yanlan Liang
- Research Center of Harmful Algae & Marine Biology, Jinan University, Guangzhou, 510632, China
| | - Huizhu Pan
- Research Center of Harmful Algae & Marine Biology, Jinan University, Guangzhou, 510632, China
| | - Lei Xie
- Research Center of Harmful Algae & Marine Biology, Jinan University, Guangzhou, 510632, China
| | - Tao Jiang
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Qingdao, 266071, China; Function Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266200, China.
| | - Tianjiu Jiang
- Research Center of Harmful Algae & Marine Biology, Jinan University, Guangzhou, 510632, China.
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He Y, Li R, Li H, Zhang S, Dai W, Wu Q, Jiang L, Zheng Z, Shen S, Chen X, Zhu Y, Wang J, Pang Z. Erythroliposomes: Integrated Hybrid Nanovesicles Composed of Erythrocyte Membranes and Artificial Lipid Membranes for Pore-Forming Toxin Clearance. ACS Nano 2019; 13:4148-4159. [PMID: 30855941 DOI: 10.1021/acsnano.8b08964] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Pore-forming toxins (PFTs) are the most common bacterial virulence proteins and play a significant role in the pathogenesis of bacterial infections; thus, PFTs are an attractive therapeutic target in bacterial infections. Inspired by the pore-forming process and mechanism of PFTs, we designed an integrated hybrid nanovesicle-the erythroliposome (called the RM-PL)-for PFT detoxification by fusing natural red blood cell (RBC) membranes with artificial lipid membranes. The lipid and RBC membranes were mutually beneficial when integrated into a hybrid nanovesicle structure. The RBC membrane endowed RM-PLs with the capacity for detoxification, while the PEGylated lipid membrane stabilized the RM-PLs and greatly improved the detoxification capacity of the RBC membrane. With α-hemolysin (Hlα) as a model PFT, we demonstrated that RM-PLs could not only significantly reduce the toxicity of Hlα to erythrocytes in vitro but also effectively sponge Hlα in vivo and rescue mice from Hlα-induced damage. Moreover, the high detoxification capacity of RM-PLs was shown to be partly related to the expression of the Hlα receptor protein, a disintegrin and metalloproteinase domain-containing protein 10 on the RBC membrane. Consequently, as a component integrating natural and artificial materials, the erythroliposome nanoplatform inspires potential strategies for antivirulence therapy.
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Affiliation(s)
- Yuwei He
- Department of Pharmaceutics, School of Pharmacy , Fudan University and Key Laboratory of Smart Drug Delivery, Ministry of Education , Shanghai 201203 , China
| | - Ruixiang Li
- Innovation Research Institute of Traditional Chinese Medicine , Shanghai University of Traditional Chinese Medicine , Shanghai 201203 , China
| | - Haichun Li
- Department of Pharmaceutics, School of Pharmacy , Fudan University and Key Laboratory of Smart Drug Delivery, Ministry of Education , Shanghai 201203 , China
| | - Shuya Zhang
- Department of Pharmaceutics, School of Pharmacy , Fudan University and Key Laboratory of Smart Drug Delivery, Ministry of Education , Shanghai 201203 , China
| | - Wentao Dai
- Shanghai Center for Bioinformation Technology , Shanghai Industrial Technology Institute , Shanghai 201203 , China
| | - Qian Wu
- Shanghai Center for Bioinformation Technology , Shanghai Industrial Technology Institute , Shanghai 201203 , China
| | - Lixian Jiang
- Innovation Research Institute of Traditional Chinese Medicine , Shanghai University of Traditional Chinese Medicine , Shanghai 201203 , China
| | - Zicong Zheng
- Department of Pharmaceutics, School of Pharmacy , Fudan University and Key Laboratory of Smart Drug Delivery, Ministry of Education , Shanghai 201203 , China
| | - Shun Shen
- Department of Pharmaceutics, School of Pharmacy , Fudan University and Key Laboratory of Smart Drug Delivery, Ministry of Education , Shanghai 201203 , China
| | - Xing Chen
- Department of Pharmaceutics, School of Pharmacy , Fudan University and Key Laboratory of Smart Drug Delivery, Ministry of Education , Shanghai 201203 , China
| | - Yuefei Zhu
- Department of Pharmaceutics, School of Pharmacy , Fudan University and Key Laboratory of Smart Drug Delivery, Ministry of Education , Shanghai 201203 , China
| | - Jianxin Wang
- Department of Pharmaceutics, School of Pharmacy , Fudan University and Key Laboratory of Smart Drug Delivery, Ministry of Education , Shanghai 201203 , China
- Institute of Integrated Chinese and Western Medicine , Fudan University , Shanghai 200040 , China
| | - Zhiqing Pang
- Department of Pharmaceutics, School of Pharmacy , Fudan University and Key Laboratory of Smart Drug Delivery, Ministry of Education , Shanghai 201203 , China
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Mehdizadeh Gohari I, Brefo-Mensah EK, Palmer M, Boerlin P, Prescott JF. Sialic acid facilitates binding and cytotoxic activity of the pore-forming Clostridium perfringens NetF toxin to host cells. PLoS One 2018; 13:e0206815. [PMID: 30403719 PMCID: PMC6221314 DOI: 10.1371/journal.pone.0206815] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 10/20/2018] [Indexed: 11/19/2022] Open
Abstract
NetF-producing type A Clostridium perfringens is an important cause of canine and foal necrotizing enteritis. NetF, related to the β-sheet pore-forming Leukocidin/Hemolysin superfamily, is considered a major virulence factor for this disease. The main purpose of this work is to demonstrate the pore-forming activity of NetF and characterize the chemical nature of its binding site. Electron microscopy using recombinant NetF (rNetF) confirmed that NetF is able to oligomerize and form large pores in equine ovarian (EO) cell membranes and sheep red blood cells. These oligomeric pores appear to be about 4–6 nm in diameter, and the number of oligomer subunits to vary from 6 to 9. Sodium periodate treatment rendered EO cells non-susceptible to NetF, suggesting that NetF binding requires cell surface carbohydrates. NetF cytotoxicity was also inhibited by a lectin that binds sialic acid, by sialidase, and by free sialic acid in excess, all of which clearly implicate sialic acid-containing membrane carbohydrates in NetF binding and/or toxicity for EO cells. Binding of NetF to sheep red blood cells was not inhibited by the gangliosides GM1, GM2 and GM3, nor did the latter promote membrane permeabilization in liposomes, suggesting that they do not constitute the cellular receptors. In contrast, treatment of EO cells with different proteases reduced their susceptibility to NetF, suggesting that the NetF receptor is a sialic acid-containing glycoprotein.
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Affiliation(s)
| | | | - Michael Palmer
- Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada
| | - Patrick Boerlin
- Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada
| | - John F. Prescott
- Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada
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Brown AC, Boesze-Battaglia K, Balashova NV, Mas Gómez N, Speicher K, Tang HY, Duszyk ME, Lally ET. Membrane localization of the Repeats-in-Toxin (RTX) Leukotoxin (LtxA) produced by Aggregatibacter actinomycetemcomitans. PLoS One 2018; 13:e0205871. [PMID: 30335797 PMCID: PMC6193665 DOI: 10.1371/journal.pone.0205871] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 10/02/2018] [Indexed: 12/31/2022] Open
Abstract
The oral bacterium, Aggregatibacter actinomycetemcomitans, which is associated with localized aggressive periodontitis, as well as systemic infections including endocarditis, produces numerous virulence factors, including a repeats-in-toxin (RTX) protein called leukotoxin (LtxA), which kills human immune cells. The strains of A. actinomycetemcomitans most closely associated with disease have been shown to produce the most LtxA, suggesting that LtxA plays a significant role in the virulence of this organism. LtxA, like many of the RTX toxins, can be divided into four functional domains: an N-terminal hydrophobic domain, which contains a significant fraction of hydrophobic residues and has been proposed to play a role in the membrane interaction of the toxin; the central domain, which contains two lysine residues that are the sites of post-translational acylation; the repeat domain that is characteristic of the RTX toxins, and a C-terminal domain thought to be involved in secretion. In its initial interaction with the host cell, LtxA must bind to both cholesterol and an integrin receptor, lymphocyte function-associated antigen-1 (LFA-1). While both interactions are essential for toxicity, the domains of LtxA involved remain unknown. We therefore undertook a series of experiments, including tryptophan quenching and trypsin digestion, to characterize the structure of LtxA upon interaction with membranes of various lipid compositions. Our results demonstrate that LtxA adopts a U-shaped conformation in the membrane, with the N- and C-terminal domains residing outside of the membrane.
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Affiliation(s)
- Angela C. Brown
- Department of Pathology, University of Pennsylvania, School of Dental Medicine, Philadelphia, PA, United States of America
| | - Kathleen Boesze-Battaglia
- Department of Biochemistry, University of Pennsylvania, School of Dental Medicine, Philadelphia, PA, United States of America
| | - Nataliya V. Balashova
- Department of Pathology, University of Pennsylvania, School of Dental Medicine, Philadelphia, PA, United States of America
| | - Nestor Mas Gómez
- Department of Pathology, University of Pennsylvania, School of Dental Medicine, Philadelphia, PA, United States of America
| | - Kaye Speicher
- Wistar Institute, Philadelphia, PA, United States of America
| | - Hsin-Yao Tang
- Wistar Institute, Philadelphia, PA, United States of America
| | - Margaret E. Duszyk
- Department of Pathology, University of Pennsylvania, School of Dental Medicine, Philadelphia, PA, United States of America
| | - Edward T. Lally
- Department of Pathology, University of Pennsylvania, School of Dental Medicine, Philadelphia, PA, United States of America
- * E-mail:
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Huang T, Lin Q, Qian X, Zheng Y, Yao J, Wu H, Li M, Jin X, Pan X, Zhang L, Guan X. Nematicidal Activity of Cry1Ea11 from Bacillus thuringiensis BRC-XQ12 Against the Pine Wood Nematode (Bursaphelenchus xylophilus). Phytopathology 2018; 108:44-51. [PMID: 28945518 DOI: 10.1094/phyto-05-17-0179-r] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The nematicidal activity of 92 Bacillus thuringiensis strains against the pine wood nematode Bursaphelenchus xylophilus, one of the world's top 10 plant-parasitic nematodes, was determined. The insecticidal crystal proteins (ICPs) from Bacillus thuringiensis BRC-XQ12 were the most toxic to Bursaphelenchus xylophilus, with a lethal concentration 50 (LC50) of 32.13 μg/ml. Because the ICPs expressed by Bacillus thuringiensis BRC-XQ12 were closest to Cry1Ea6 and B. thuringiensis BRC-XQ12 contained four kinds of cry1 subgenes (cry1Aa, cry1Cb, cry1Ea, and cry1Ia), Cry1Ea was most likely to be the key active component against the nematode. The 3,516-bp cry1Ea11 gene from BRC-XQ12, as designated by the B. thuringiensis δ-endotoxin nomenclature committee, was expressed in Escherichia coli. Purified Cry1Ea11 showed an LC50 of 32.53 and 23.23 μg/ml at 24 and 48 h, with corresponding virulence equations of Y = 32.15X + 1.38 (R2 = 0.9951) and Y = 34.29X + 3.16 (R2 = 0.9792), respectively. In order to detect the pathway of B. thuringiensis Cry1Ea11 into Bursaphelenchus xylophilus, the nematode was fed with NHS-rhodamine-labeled GST-Cry1Ea11. The results of confocal laser-scanning microscopy showed that the 159-kDa GST-Cry1Ea11 could be detected in the stylet and the esophageal lumen of the pine wood nematode, indicating that GST-Cry1Ea11 could enter into the nematode through the stylet. As far as we know, no Cry1 proteins have been shown to have activity against plant-parasitic nematodes before. These results demonstrate that Cry1Ea11 is a promising nematicidal protein for controlling pine wilt disease rendered by B. xylophilus, further dramatically broadening the spectrum of Bacillus thuringiensis ICPs.
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Affiliation(s)
- Tianpei Huang
- All authors: State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology (Ministry of Education), College of Life Sciences, Fujian Agriculture and Forestry University, and first, fifth, sixth, seventh, eighth, ninth, tenth, and eleventh authors: Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fuzhou, Fujian, People's Republic of China, 350002
| | - Qunxin Lin
- All authors: State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology (Ministry of Education), College of Life Sciences, Fujian Agriculture and Forestry University, and first, fifth, sixth, seventh, eighth, ninth, tenth, and eleventh authors: Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fuzhou, Fujian, People's Republic of China, 350002
| | - Xiaoli Qian
- All authors: State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology (Ministry of Education), College of Life Sciences, Fujian Agriculture and Forestry University, and first, fifth, sixth, seventh, eighth, ninth, tenth, and eleventh authors: Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fuzhou, Fujian, People's Republic of China, 350002
| | - Ying Zheng
- All authors: State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology (Ministry of Education), College of Life Sciences, Fujian Agriculture and Forestry University, and first, fifth, sixth, seventh, eighth, ninth, tenth, and eleventh authors: Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fuzhou, Fujian, People's Republic of China, 350002
| | - Junmin Yao
- All authors: State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology (Ministry of Education), College of Life Sciences, Fujian Agriculture and Forestry University, and first, fifth, sixth, seventh, eighth, ninth, tenth, and eleventh authors: Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fuzhou, Fujian, People's Republic of China, 350002
| | - Huachuan Wu
- All authors: State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology (Ministry of Education), College of Life Sciences, Fujian Agriculture and Forestry University, and first, fifth, sixth, seventh, eighth, ninth, tenth, and eleventh authors: Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fuzhou, Fujian, People's Republic of China, 350002
| | - Mengmeng Li
- All authors: State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology (Ministry of Education), College of Life Sciences, Fujian Agriculture and Forestry University, and first, fifth, sixth, seventh, eighth, ninth, tenth, and eleventh authors: Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fuzhou, Fujian, People's Republic of China, 350002
| | - Xin Jin
- All authors: State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology (Ministry of Education), College of Life Sciences, Fujian Agriculture and Forestry University, and first, fifth, sixth, seventh, eighth, ninth, tenth, and eleventh authors: Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fuzhou, Fujian, People's Republic of China, 350002
| | - Xiaohong Pan
- All authors: State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology (Ministry of Education), College of Life Sciences, Fujian Agriculture and Forestry University, and first, fifth, sixth, seventh, eighth, ninth, tenth, and eleventh authors: Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fuzhou, Fujian, People's Republic of China, 350002
| | - Lingling Zhang
- All authors: State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology (Ministry of Education), College of Life Sciences, Fujian Agriculture and Forestry University, and first, fifth, sixth, seventh, eighth, ninth, tenth, and eleventh authors: Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fuzhou, Fujian, People's Republic of China, 350002
| | - Xiong Guan
- All authors: State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology (Ministry of Education), College of Life Sciences, Fujian Agriculture and Forestry University, and first, fifth, sixth, seventh, eighth, ninth, tenth, and eleventh authors: Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fuzhou, Fujian, People's Republic of China, 350002
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Geetha I, Regnakumari P, Manonmani AM. Separation, quantification and mosquito larvicidal activity of insecticidal crystal proteins of Bacillus thuringiensis var. israelensis (VCRC B17; MTCC 5596). J Vector Borne Dis 2017; 54:187-190. [PMID: 28748842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023] Open
Affiliation(s)
- I Geetha
- Unit of Microbiology and Molecular Biology, ICMR-Vector Control Research Centre, Puducherry, India
| | - P Regnakumari
- Unit of Microbiology and Molecular Biology, ICMR-Vector Control Research Centre, Puducherry, India
| | - A M Manonmani
- Unit of Microbiology and Molecular Biology, ICMR-Vector Control Research Centre, Puducherry, India
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Gapon MN, Telesmanitch NR, Ternovskaya LN, Chaika SO, Chaika IA, Mikashinovitch ZI, Tverdokhlebova TI. [The time-of-flight mass spectrometer intra-specific diagnostic of strains of Escherichia isolated from patient]. Klin Lab Diagn 2016; 61:371-375. [PMID: 30601631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The time-of-flight mass spectrometer analysis of freshly separated human colibacillus populations for identification of markers of proteom specific for hemolytic and non-hemolytic strains, Escherichia-associant of opportunistic enterobacteria. The material consisted of 20 strains of mono-population of hemolytic Escherichia; 100 strains of mono-population of non-hemolytic Escherichia; 15 non-hemolytic strains isolated from association with opportunistic enterobacteria. The protein profiling was implemented on mass spectrometer MALDI-TOF MS Autoflex “Bruker Daltonik”. The value within type of peak mass-charge with 100% intensity equal to 9000 Da can be used as a differentiating indication of detection of hemolytic Escherichia at mass-spectrometer biotyping. The proteom characteristics of strains of various populations within Escherichia coli species are given. The taxon-specific markers for proteom differentiation of population of Escherichia are given too.
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Randhawa GJ, Chhabra R, Bhoge RK, Singh M. Visual and Real-Time Event-Specific Loop-Mediated Isothermal Amplification Based Detection Assays for Bt Cotton Events MON531 and MON15985. J AOAC Int 2015; 98:1207-14. [PMID: 26525238 DOI: 10.5740/jaoacint.14-269] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Bt cotton events MON531 and MON15985 are authorized for commercial cultivation in more than 18 countries. In India, four Bt cotton events have been commercialized; more than 95% of total area under genetically modified (GM) cotton cultivation comprises events MON531 and MON15985. The present study reports on the development of efficient event-specific visual and real-time loop-mediated isothermal amplification (LAMP) assays for detection and identification of cotton events MON531 and MON15985. Efficiency of LAMP assays was compared with conventional and real-time PCR assays. Real-time LAMP assay was found time-efficient and most sensitive, detecting up to two target copies within 35 min. The developed real-time LAMP assays, when combined with efficient DNA extraction kit/protocol, may facilitate onsite GM detection to check authenticity of Bt cotton seeds.
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Li M, Zhu M, Zhang C, Liu X, Wan Y. Uniform orientation of biotinylated nanobody as an affinity binder for detection of Bacillus thuringiensis (Bt) Cry1Ac toxin. Toxins (Basel) 2014; 6:3208-22. [PMID: 25474492 PMCID: PMC4280530 DOI: 10.3390/toxins6123208] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2014] [Revised: 11/10/2014] [Accepted: 11/17/2014] [Indexed: 12/26/2022] Open
Abstract
Nanobodies are the smallest natural fragments with useful properties such as high affinity, distinct paratope and high stability, which make them an ideal tool for detecting target antigens. In this study, we generated and characterized nanobodies against the Cry1Ac toxin and applied them in a biotin-streptavidin based double antibodies (nanobodies) sandwich-ELISA (DAS-ELISA) assay. After immunizing a camel with soluble Cry1Ac toxin, a phage displayed library was constructed to generate Nbs against the Cry1Ac toxin. Through successive rounds of affinity bio-panning, four nanobodies with greatest diversity in CDR3 sequences were obtained. After affinity determination and conjugating to HRP, two nanobodies with high affinity which can recognize different epitopes of the same antigen (Cry1Ac) were selected as capture antibody (Nb61) and detection antibody (Nb44). The capture antibody (Nb61) was biotinylated in vivo for directional immobilization on wells coated with streptavidin matrix. Both results of specificity analysis and thermal stability determination add support for reliability of the following DAS-ELISA with a minimum detection limit of 0.005 μg·mL-1 and a working range 0.010-1.0 μg·mL-1. The linear curve displayed an acceptable correlation coefficient of 0.9976. These results indicated promising applications of nanobodies for detection of Cry1Ac toxin with biotin-streptavidin based DAS-ELISA system.
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Affiliation(s)
- Min Li
- The Key Laboratory of Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Sipailou NO. 2, Southeast University, Nanjing 210096, China.
| | - Min Zhu
- The Key Laboratory of Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Sipailou NO. 2, Southeast University, Nanjing 210096, China.
| | - Cunzheng Zhang
- Institute of Food Safety, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
| | - Xianjin Liu
- Institute of Food Safety, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
| | - Yakun Wan
- The Key Laboratory of Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Sipailou NO. 2, Southeast University, Nanjing 210096, China.
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Raghu Patil J, Desai SN, Roy P, Durgaiah M, Saravanan RS, Vipra A. Simulated hatchery system to assess bacteriophage efficacy against Vibrio harveyi. Dis Aquat Organ 2014; 112:113-119. [PMID: 25449322 DOI: 10.3354/dao02806] [Citation(s) in RCA: 13] [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] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Vibriosis caused by luminous Vibrio harveyi commonly contributes to poor survival in shrimp hatcheries and aquaculture ponds. Lytic bacteriophages pathogenic for V. harveyi are currently being investigated as an alternative to antibiotics to prevent vibriosis. Here, 8 bacteriophages were isolated from oysters and clams using V. harveyi strains as baiting hosts. Among these bacteriophages, 1 strain (VHP6b) identified as broadly pathogenic for 27 V. harveyi strains examined was further characterized by electron microscopy and genome sequence analysis. Phage VHP6b possessed a tail and morphology consistent with it being a member of the family Siphoviridae, and its genome and proteome were most closely related to the Vibrio phages SSP02 and MAR10. An integrase gene essential for lysogeny was not evident. The ability of bacteriophage VHP6b to protect shrimp postlarvae against vibriosis caused by V. harveyi strain VH6 was demonstrated in a model system designed to simulate typical hatchery conditions. Bacteriophage treatment improved survival of postlarvae by 40 to 60% under these conditions, so therapies based on this or other bacteriophages may be useful in shrimp hatcheries.
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Affiliation(s)
- J Raghu Patil
- Microbiology, In vivo, and Molecular Biology Team, Gangagen Biotechnologies Pvt. Ltd., No. 12, 5th Cross, Raghavendra layout, Opp. MEI Ltd., Tumkur Road, Yeshwantpur, Bangalore-560022, India
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El-kersh TA, Al-akeel RA, Al-sheikh YA, Alharbi SA. Isolation and distribution of mosquito-larvicidal cry genes in Bacillus thuringiensis strains native to Saudi Arabia. Trop Biomed 2014; 31:616-632. [PMID: 25776587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A total of 157 environmental samples were collected from 11 ecological regions across Saudi Arabia to isolate native Bacillus thuringiensis (Bt) strains. Bt isolates (n=103) were recovered by the 50% (v/v) ethanol treatment method with Bt index range of 0.01 to 0.4. Most of Bt isolates showed spherical crystals (54%), while, irregular, bi-pyramidal, and spore-attached crystal constituted 27, 16 and 3% respectively. PCR analysis with eight general and specific dipteran primers of Cry and Cyt genes, revealed positive amplification for cry4 & cyt1, and cry4A, cry4B and cyt2, and cry 10 and cry 11 genes in 28%, 26%, 22%, and 25% of tested strains respectively; whereas cry2 gene was not detected except with the reference Bt kurstaki HD-1 strain. Bioassays against Aedes caspuis and Culex pipiens larvae indicated that 11 strains displayed better larvicidal activity compared with Bacillus thuringiensis H14 (Bti) reference (LC50 0.6 μg/ml) strain against Ae. caspuis, but only two strains (620A & 633R1, LC50 of 0.09 μg/ml & 0.064 μg/ml) that gave significant enhancement. Additionally, one strain (633R1) showed LC50 similar to that of Bti H14 (LC50 0.064 μg/ml) against Cx. pipiens. With the exception of cyt primers, sequenced DNA of all positive primers amplicons revealed 95 to 99% identity in GenBank with Bacillus thuringiensis subsp. israelensis plasmid pBtoxis and also correlated with its SDS-PAGE expressed protein profiles analysis. It is hoped that our wild bio-insecticide Bt strains can be explored in future in the control of mosquito-vector borne diseases in Saudi Arabia.
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Affiliation(s)
- T A El-kersh
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Saud University, Riyadh 11433, P.O. Box 10219
| | - R A Al-akeel
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Saud University, Riyadh 11433, P.O. Box 10219
| | - Y A Al-sheikh
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Saud University, Riyadh 11433, P.O. Box 10219
| | - S A Alharbi
- Yanbu General Hospital, Yanbu City, Ministry of Health, Saudi Arabia
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12
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Thomas S, Smits SHJ, Schmitt L. A simple in vitro acylation assay based on optimized HlyA and HlyC purification. Anal Biochem 2014; 464:17-23. [PMID: 25016191 DOI: 10.1016/j.ab.2014.07.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 06/26/2014] [Accepted: 07/01/2014] [Indexed: 11/29/2022]
Abstract
HlyA is a toxin secreted by uropathogenic Escherichia coli strains. HlyA belongs to the repeats in the toxin protein family and needs (i) a posttranslational, fatty acylation at two internal lysines by the acyltransferase HlyC and (ii) extracellular ion binding to achieve its active conformation. Both processes are not fully understood and experiments are often limited due to the low amounts of protein available. Here, we present an optimized purification protocol for the proteins involved in HlyA activation as well as a quick and nonradioactive assay for in vitro HlyA acylation. These may simplify future experiments, e.g., activity scanning and characterization of HlyA or HlyC mutants as demonstrated with single and double HlyA lysine mutants.
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Affiliation(s)
- Sabrina Thomas
- Institute of Biochemistry, Heinrich Heine University Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany
| | - Sander H J Smits
- Institute of Biochemistry, Heinrich Heine University Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany
| | - Lutz Schmitt
- Institute of Biochemistry, Heinrich Heine University Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany.
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13
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Monecke S, Müller E, Büchler J, Stieber B, Ehricht R. Staphylococcus aureus in vitro secretion of alpha toxin (hla) correlates with the affiliation to clonal complexes. PLoS One 2014; 9:e100427. [PMID: 24940872 PMCID: PMC4062534 DOI: 10.1371/journal.pone.0100427] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Accepted: 05/28/2014] [Indexed: 11/19/2022] Open
Abstract
The alpha toxin of Staphylococcus aureus is a pore forming toxin that penetrates host cell membranes causing osmotic swelling, rupture, lysis and subsequently cell death. Haemolysin alpha is toxic to a wide range of different mammalian cells; i.e., neurotoxic, dermonecrotic, haemolytic, and it can cause lethality in a wide variety of animals. In this study, the in vitro alpha toxin production of 648 previously genotyped isolates of S. aureus was measured quantitatively using antibody microarrays. Isolates originated from medical and veterinary settings and were selected in order to represent diverse clonal complexes and defined clinical conditions. Generally, the production of alpha toxin in vitro is related to the clonal complex affiliation. For clonal complexes CC22, CC30, CC45, CC479, CC705 and others, invariably no alpha toxin production was noted under the given in vitro conditions, while others, such as CC1, CC5, CC8, CC15 or CC96 secreted variable or high levels of alpha toxin. There was no correlation between alpha toxin yield and clinical course of the disease, or between alpha toxin yield and host species.
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Affiliation(s)
- Stefan Monecke
- Alere Technologies GmbH, Jena, Germany
- Institute for Medical Microbiology and Hygiene, Technische Universität Dresden, Dresden, Germany
- * E-mail:
| | | | - Joseph Büchler
- Alere San Diego, Inc., San Diego, California, United States of America
| | - Bettina Stieber
- Alere Technologies GmbH, Jena, Germany
- Institute for Medical Microbiology and Hygiene, Technische Universität Dresden, Dresden, Germany
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14
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Mueting SA, Strain KE, Lydy MJ. Validation of an extraction method for Cry1Ab protein from soil. Environ Toxicol Chem 2014; 33:18-25. [PMID: 23996731 DOI: 10.1002/etc.2383] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [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: 05/30/2013] [Revised: 08/13/2013] [Accepted: 08/26/2013] [Indexed: 06/02/2023]
Abstract
Corn expressing insecticidal proteins derived from Bacillus thuringiensis (Bt corn) has increased in usage in the United States from 8% of total corn acreage in 1996 to 67% in 2012. Because of this increase, it is important to be able to monitor the fate and transport of the insecticidal Bt proteins to evaluate environmental exposure and effects. Accurate and validated methods are needed to quantify these proteins in environmental matrices. A method to extract Bt Cry1Ab proteins from 3 soil types using a 10× phosphate-buffered saline with Tween buffer and a commercially available enzyme-linked immunosorbent assay (ELISA) was validated through a series of 6 tests. The validation process for Cry1Ab extractions in soil has not yet been reported in the scientific literature. The extraction buffer and each soil matrix were tested and validated for the ELISA. Extraction efficiencies were 41%, 74%, and 89% for the 3 soil types and were significantly correlated with the organic matter content of the soil. Despite low recoveries, consistent results with low coefficients of variation allowed for accurate measurements. Through validating this method with 3 different soils, a sensitive, specific, precise, and accurate quantification of Bt Cry1Ab was developed. The validation process can be expanded and implemented in other environmental matrices, adding consistency to data across a wide range of samples.
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Affiliation(s)
- Sara A Mueting
- Center for Fisheries, Aquaculture, and Aquatic Sciences and Department of Zoology, Southern Illinois University, Carbondale, Illinois, USA
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15
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Urban JF, Hu Y, Miller MM, Scheib U, Yiu YY, Aroian RV. Bacillus thuringiensis-derived Cry5B has potent anthelmintic activity against Ascaris suum. PLoS Negl Trop Dis 2013; 7:e2263. [PMID: 23818995 PMCID: PMC3688533 DOI: 10.1371/journal.pntd.0002263] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 04/27/2013] [Indexed: 11/18/2022] Open
Abstract
Ascaris suum and Ascaris lumbricoides are two closely related geo-helminth parasites that ubiquitously infect pigs and humans, respectively. Ascaris suum infection in pigs is considered a good model for A. lumbricoides infection in humans because of a similar biology and tissue migration to the intestines. Ascaris lumbricoides infections in children are associated with malnutrition, growth and cognitive stunting, immune defects, and, in extreme cases, life-threatening blockage of the digestive tract and aberrant migration into the bile duct and peritoneum. Similar effects can be seen with A. suum infections in pigs related to poor feed efficiency and performance. New strategies to control Ascaris infections are needed largely due to reduced treatment efficacies of current anthelmintics in the field, the threat of resistance development, and the general lack of new drug development for intestinal soil-transmitted helminths for humans and animals. Here we demonstrate for the first time that A. suum expresses the receptors for Bacillus thuringiensis crystal protein and novel anthelmintic Cry5B, which has been previously shown to intoxicate hookworms and which belongs to a class of proteins considered non-toxic to vertebrates. Cry5B is able to intoxicate A. suum larvae and adults and triggers the activation of the p38 mitogen-activated protein kinase pathway similar to that observed with other nematodes. Most importantly, two moderate doses of 20 mg/kg body weight (143 nM/kg) of Cry5B resulted in a near complete cure of intestinal A. suum infections in pigs. Taken together, these results demonstrate the excellent potential of Cry5B to treat Ascaris infections in pigs and in humans and for Cry5B to work effectively in the human gastrointestinal tract. Ascaris suum is an intestinal parasitic nematode of pigs that is very closely related to Ascaris lumbricoides, a major intestinal parasitic nematode of humans that infects more than one billion people worldwide. Because of reduced efficacy and the threat of resistance to the current small set of approved drugs to treat Ascaris infections, new treatments are needed. Here we test against A. suum infections the effectiveness of Cry5B, a nematode-killing protein made by the natural soil bacterium Bacillus thuringiensis and representing a promising new class of anthelmintics. We demonstrate for the first time that A. suum possesses the receptors to bind Cry5B and that Cry5B can kill A. suum larvae and adults in culture. Most importantly, we demonstrate that oral administration of Cry5B to pigs infected with A. suum larvae results in a near complete elimination of the infection. Given the similarities between A. suum and A. lumbricoides and the similarity between the pig and human gastrointestinal tracts, our data indicate that Cry5B has excellent potential to treat Ascaris infections in veterinary animals and in humans.
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Affiliation(s)
- Joseph F. Urban
- USDA, Agricultural Research Service, Beltsville Human Nutrition Research Center, Diet, Genomics, and Immunology Laboratory, Beltsville, Maryland, United States of America
| | - Yan Hu
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Melanie M. Miller
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Ulrike Scheib
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Ying Y. Yiu
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Raffi V. Aroian
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
- * E-mail:
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Shu C, Zhang J, Chen G, Liang G, He K, Crickmore N, Huang D, Zhang J, Song F. Use of a pooled clone method to isolate a novel Bacillus thuringiensis Cry2A toxin with activity against Ostrinia furnacalis. J Invertebr Pathol 2013; 114:31-3. [PMID: 23711413 DOI: 10.1016/j.jip.2013.05.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Revised: 04/26/2013] [Accepted: 05/16/2013] [Indexed: 12/26/2022]
Abstract
A pooled clone method was developed to screen for cry2A genes. This metagenomic method avoids the need to analyse isolated Bacillus thuringiensis strains by performing gene specific PCR on plasmid-enriched DNA prepared from a pooled soil sample. Using this approach the novel holotype gene cry2Ah1 was cloned and characterized. The toxin gene was over-expressed in Escherichia coli Rosetta (DE3) and the expressed toxin accumulated in both the soluble and insoluble fractions. The soluble Cry2Ah1 was found to have a weight loss activity against Ostrinia furnacalis, and a growth inhibitory activity to both Cry1Ac-susceptible and resistant Helicoverpa armigera populations.
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Affiliation(s)
- Changlong Shu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China
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17
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Lin YR, Chen YL, Wang KB, Wu YF, Wang YK, Huang SC, Liu TA, Nayak M, Yip BS, Wu TK. The thermostable direct hemolysin from Grimontia hollisae causes acute hepatotoxicity in vitro and in vivo. PLoS One 2013; 8:e56226. [PMID: 23437095 PMCID: PMC3578849 DOI: 10.1371/journal.pone.0056226] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 01/07/2013] [Indexed: 12/02/2022] Open
Abstract
Background G. hollisae thermostable direct hemolysin (Gh-TDH) is produced by most strains of G. hollisae. This toxin has been reported to be absorbed in the intestines in humans. Secondary liver injury might be caused by venous return of the toxin through the portal system. We aimed to firstly analyze the in vitro and in vivo hepatotoxicity of Gh-TDH. Methods Liver cells (primary human non-cancer cell and FL83B mouse cells) were treated and mice (BALB/c) were fed with this toxin to investigate its hepatotoxicity. Morphological examination and cytotoxicity assays using liver cells were also performed. Fluorescein isothiocyanate-conjugated toxin was used to analyze the localization of this protein in liver cells. Mice were subjected to liver function measurements and liver biopsies following toxin treatment and wild-type bacterial infection. PET (positron emission tomography)/CT (computed tomography) images were taken to assess liver metabolism during acute injury and recovery. Results The effect of hepatotoxicity was dose and time dependent. Cellular localization showed that the toxin was initially located around the cellular margins and subsequently entered the nucleus. Liver function measurements and liver biopsies of the mice following treatment with toxin or infection with wild-type Grimontia hollisae showed elevated levels of transaminases and damage to the periportal area, respectively. The PET/CT images revealed that the reconstruction of the liver continued for at least one week after exposure to a single dose of the toxin or bacterial infection. Conclusions The hepatotoxicity of Gh-TDH was firstly demonstrated. The damage was located in the periportal area of the liver, and the liver became functionally insufficient.
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Affiliation(s)
- Yan-Ren Lin
- Department of Biological Science and Technology, National Chiao Tung University, Hsin-Chu, Taiwan, Republic of China
- Department of Emergency Medicine, Changhua Christian Hospital, Changhua, Taiwan, Republic of China
- School of Medicine, Chung Shan Medical University, Taichung, Taiwan, Republic of China
| | - Yao-Li Chen
- Transplant Medicine and Surgery Research Centre, Changhua Christian Hospital, Changhua, Taiwan, Republic of China
- School of Medicine, Chung Shan Medical University, Taichung, Taiwan, Republic of China
| | - Keh-Bin Wang
- Department of Nuclear Medicine, Kuang Tien General Hospital, Taichung, Taiwan, Republic of China
| | - Yi-Fang Wu
- Department of Biological Science and Technology, National Chiao Tung University, Hsin-Chu, Taiwan, Republic of China
| | - Yu-Kuo Wang
- Department of Biological Science and Technology, National Chiao Tung University, Hsin-Chu, Taiwan, Republic of China
- * E-mail: (Y-KW); (B-SY); (T-KW)
| | - Sheng-Cih Huang
- Department of Biological Science and Technology, National Chiao Tung University, Hsin-Chu, Taiwan, Republic of China
| | - Tzu-An Liu
- Institute of Cellular and System Medicine, National Health Research Institutes, Zhunan, Miaoli County, Taiwan, Republic of China
| | - Manoswini Nayak
- Department of Biological Science and Technology, National Chiao Tung University, Hsin-Chu, Taiwan, Republic of China
| | - Bak-Sau Yip
- Department of Neurology, National Taiwan University Hospital Hsin Chu Branch, Hsin-Chu, Taiwan, Republic of China
- * E-mail: (Y-KW); (B-SY); (T-KW)
| | - Tung-Kung Wu
- Department of Biological Science and Technology, National Chiao Tung University, Hsin-Chu, Taiwan, Republic of China
- * E-mail: (Y-KW); (B-SY); (T-KW)
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18
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Li YL, Fang ZX, You J. Application of Box-Behnken experimental design to optimize the extraction of insecticidal Cry1Ac from soil. J Agric Food Chem 2013; 61:1464-1470. [PMID: 23327690 DOI: 10.1021/jf304970g] [Citation(s) in RCA: 15] [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] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A validated method for analyzing Cry proteins is a premise to study the fate and ecological effects of contaminants associated with genetically engineered Bacillus thuringiensis crops. The current study has optimized the extraction method to analyze Cry1Ac protein in soil using a response surface methodology with a three-level-three-factor Box-Behnken experimental design (BBD). The optimum extraction conditions were at 21 °C and 630 rpm for 2 h. Regression analysis showed a good fit of the experimental data to the second-order polynomial model with a coefficient of determination of 0.96. The method was sensitive and precise with a method detection limit of 0.8 ng/g dry weight and relative standard deviations at 7.3%. Finally, the established method was applied for analyzing Cry1Ac protein residues in field-collected soil samples. Trace amounts of Cry1Ac protein were detected in the soils where transgenic crops have been planted for 8 and 12 years.
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Affiliation(s)
- Yan-Liang Li
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, Peoples' Republic of China
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19
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Guidi V, Lehner A, Lüthy P, Tonolla M. Dynamics of Bacillus thuringiensis var. israelensis and Lysinibacillus sphaericus spores in urban catch basins after simultaneous application against mosquito larvae. PLoS One 2013; 8:e55658. [PMID: 23390547 PMCID: PMC3563526 DOI: 10.1371/journal.pone.0055658] [Citation(s) in RCA: 14] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 12/28/2012] [Indexed: 11/23/2022] Open
Abstract
Bacillus thuringiensis var. israelensis (Bti) and Lysinibacillus sphaericus (Lsph) are extensively used in mosquito control programs. These biocides are the active ingredients of a commercial larvicide. Quantitative data on the fate of both Bti and Lsph applied together for the control of mosquitoes in urban drainage structures such as catch basins are lacking. We evaluated the dynamics and persistence of Bti and Lsph spores released through their concomitant application in urban catch basins in southern Switzerland. Detection and quantification of spores over time in water and sludge samples from catch basins were carried out using quantitative real-time PCR targeting both cry4A and cry4B toxin genes for Bti and the binA gene for Lsph. After treatment, Bti and Lsph spores attained concentrations of 3.76 (±0.08) and 4.13 (±0.09) log ml−1 in water, then decreased progressively over time, reaching baseline values. For both Bti and Lsph, spore levels in the order of 105 g−1 were observed in the bottom sludge two days after the treatment and remained constant for the whole test period (275 days). Indigenous Lsph strains were isolated from previously untreated catch basins. A selection of those was genotyped using pulsed field gel electrophoresis of SmaI-digested chromosomal DNA, revealing that a subset of isolates were members of the clonal population of strain 2362. No safety issues related to the use of this biopesticide in the environment have been observed during this study, because no significant increase in the number of spores was seen during the long observation period. The isolation of native Lysinibacillus sphaericus strains belonging to the same clonal population as strain 2362 from catch basins never treated with Lsph-based products indicates that the use of a combination of Bti and Lsph for the control of mosquitoes does not introduce non-indigenous microorganisms in this area.
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Affiliation(s)
- Valeria Guidi
- Microbial Ecology Group, Microbiology Unit, Plant Biology Department, University of Geneva, Genève, Switzerland
- Institute of Microbiology, Bellinzona, Switzerland
| | - Angelika Lehner
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Zürich, Switzerland
| | - Peter Lüthy
- Institute of Microbiology, ETH Zürich, Zürich, Switzerland
| | - Mauro Tonolla
- Microbial Ecology Group, Microbiology Unit, Plant Biology Department, University of Geneva, Genève, Switzerland
- Institute of Microbiology, Bellinzona, Switzerland
- * E-mail:
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Sander M, Tomaszewski JE, Madliger M, Schwarzenbach RP. Adsorption of insecticidal Cry1Ab protein to humic substances. 1. Experimental approach and mechanistic aspects. Environ Sci Technol 2012; 46:9923-9931. [PMID: 22862304 DOI: 10.1021/es3022478] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Adsorption is a key process affecting the fate of insecticidal Cry proteins (Bt toxins), produced by genetically modified Bt crops, in soils. However, the mechanisms of adsorption to soil organic matter (SOM) remain poorly understood. This work assesses the forces driving the adsorption of Cry1Ab to Leonardite humic acid (LHA), used as a model for SOM. We studied the effects of solution pH and ionic strength (I) on adsorption using a quartz crystal microbalance with dissipation monitoring and optical waveguide lightmode spectroscopy. Initial Cry1Ab adsorption rates were close to diffusion-limited and resulted in extensive adsorption, even at pH >6, at which LHA and Cry1Ab carry negative net charges. Adsorption increased with decreasing I at pH >6, indicating Cry1Ab-LHA patch-controlled electrostatic attraction via positively charged domains of Cry1Ab. Upon rinsing, only a fraction of Cry1Ab desorbed, suggesting a range of interaction energies of Cry1Ab with LHA. Different interaction energies likely resulted from nonuniformity in the LHA surface polarity, with higher Cry1Ab affinities to more apolar LHA regions due to the hydrophobic effect. Contributions from the hydrophobic effect were substantiated by comparison of the adsorption of Cry1Ab and the reference proteins albumin and lysozyme to LHA and to apolar and polar model surfaces.
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Affiliation(s)
- Michael Sander
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), Swiss Federal Institute of Technology, ETH Zurich, Zurich, Switzerland.
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21
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Tomaszewski JE, Madliger M, Pedersen JA, Schwarzenbach RP, Sander M. Adsorption of insecticidal Cry1Ab protein to humic substances. 2. Influence of humic and fulvic acid charge and polarity characteristics. Environ Sci Technol 2012; 46:9932-9940. [PMID: 22862550 DOI: 10.1021/es302248u] [Citation(s) in RCA: 12] [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] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Assessing the fate and potential risks of transgenic Cry proteins in soils requires understanding of Cry protein adsorption to soil particles. The companion paper provided evidence that patch-controlled electrostatic attraction (PCEA) and the hydrophobic effect contributed to Cry1Ab protein adsorption to an apolar humic acid (HA). Here, we further assess the relative importance of these contributions by comparing Cry1Ab adsorption to seven humic substances varying in polarity and charge, at different solution pH and ionic strength, I. Cry1Ab adsorption to relatively apolar HAs at I = 50 mM exhibited rapid initial rates, was extensive, and was only partially reversible at pH 5-8, whereas adsorption to more polar fulvic acids was weak and reversible or absent at pH >6. The decrease in adsorption with increasing HS polarity at all tested pH strongly supports a large contribution from the hydrophobic effect to adsorption, particularly at I = 50 mM when PCEA was effectively screened. Using insect bioassays, we further show that Cry1Ab adsorbed to a selected HA retained full insecticidal activity. Our results highlight the need to consider adsorption to soil organic matter in models that assess the fate of Cry proteins in soils.
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Affiliation(s)
- Jeanne E Tomaszewski
- Swiss Federal Institute of Technology, ETH Zurich, Institute of Biogeochemistry and Pollutant Dynamics (IBP), Zurich, Switzerland
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22
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Ren ZQ, Zheng YL, Gan SZ, Lv QY, Hao HJ, Jiang YQ, Zong H. [Construction and activities of suilysin mutants]. Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi 2012; 28:580-582. [PMID: 22691347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
AIM To construct the suilysin mutant without hemolytic activity and evaluate its functions. METHODS The proline in 353 site of suilysin was site-directed mutated to alanine, leucine and valine, respectively. The recombinant mutants were renaturated and purified by immobilized metal ion affinity chromatography, and the purified proteins were evaluated in the hemolytic activity and immunogenicity. RESULTS We obtained three mutants, SLY(P353A), SLY(P353L) and SLY(P353V). The SLY(P353V) mutant had non-hemolytic activity. Western blotting and animal experiments showed that SLY(P353V) mutant still had immunogenicity. CONCLUSION Suilysin mutant SLY(P353V) has no hemolytic activity but remains immunogenicity.
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Affiliation(s)
- Zhi-qiang Ren
- College of Life Science, Sichuan Normal University, Chengdu, China.
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Abstract
The use of nanopores is a powerful new frontier in single-molecule sciences. Nanopores have been used effectively in exploring various biophysical features of small polypeptides and proteins, such as their folding state and structure, ligand interactions, and enzymatic activity. In particular, the α-hemolysin (αHL) protein pore has been used extensively for the detection, characterization, and analysis of polypeptides because this protein nanopore is highly robust, versatile, and tractable under various experimental conditions. Inspired by the mechanisms of protein translocation across the outer membrane translocases of mitochondria, we have shown the ability to use nanopore-probe techniques in controlling a single protein using engineered αHL pores. Here, we provide a detailed protocol for the preparation of αHL protein nanopores. Moreover, we demonstrate that placing attractive electrostatic traps is instrumental in tackling single-molecule stochastic sensing of folded proteins.
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Lam SK, Ng TB. First report of an anti-tumor, anti-fungal, anti-yeast and anti-bacterial hemolysin from Albizia lebbeck seeds. Phytomedicine 2011; 18:601-608. [PMID: 20850957 DOI: 10.1016/j.phymed.2010.08.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2010] [Revised: 06/11/2010] [Accepted: 08/11/2010] [Indexed: 05/29/2023]
Abstract
A monomeric 5.5-kDa protein with hemolytic activity toward rabbit erythrocytes was isolated from seeds of Albizia lebbeck by using a protocol that involved ion-exchange chromatography on Q-Sepharose and SP-Sepharose, hydrophobic interaction chromatography on Phenyl-Sepharose, and gel filtration on Superdex 75. It was unadsorbed on both Q-Sepharose and SP-Sepharose, but adsorbed on Phenyl-Sepharose. Its hemolytic activity was fully preserved in the pH range 0-14 and in the temperature range 0-100 °C, and unaffected in the presence of a variety of metal ions and carbohydrates. The hemolysin reduced viability of murine splenocytes and inhibited proliferation of MCF-7 breast cancer cells and HepG2 hepatoma cells with an IC₅₀ of 0.21, 0.97, and 1.37 μM, respectively. It impeded mycelial growth in the fungi Rhizoctonia solani with an IC₅₀ of 39 μM but there was no effect on a variety of other filamentous fungi, including Fusarium oxysporum, Helminthosporium maydis, Valsa mali and Mycosphaerella arachidicola. Lebbeckalysin inhibited growth of Escherichia coli with an IC₅₀ of 0.52 μM.
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Affiliation(s)
- Sze Kwan Lam
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China.
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Lv QY, Hao HJ, Bi LL, Zheng YL, Jiang YQ, Lv SX. [Purification and biological activities analysis of streptococcus suis Serotype 2 suilysin]. Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi 2011; 27:374-376. [PMID: 21481309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
AIM To explore the purification methods of wild-type and recombinant suilysin and to evaluate their biological activities. METHODS Wild-type suilysin was purified by ammonium sulfate precipitation, anion-exchange chromatography and hydrophobic chromatography in turn, while recombinant suilysin was first refolded and purified by immobilized metal ion affinity chromatography, and further purified by Thiopropyl Sepharose 6B. The biological activities were evaluated by hemolysis test, cytotoxicity assay. RESULTS Both prepared wild-type and recombinant suilysin, with purify over 90%, have hemolysis activity and could injure target cells at high concentration while cholesterol could completely inhibit their activities. CONCLUSION Recombinant suilysin has similar biological activities with wild-type suilysin, and this work contributed to further study the functions of suilysin on pathogenesis of steptococcus suis.
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Affiliation(s)
- Qing-yu Lv
- College of Biological Science & Technology, Shenyang Agricultural University, Shenyang 11086, China.
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Hannon ER, Sisterson MS, Stock SP, Carrière Y, Tabashnik BE, Gassmann AJ. Effects of four nematode species on fitness costs of pink bollworm resistance to Bacillus thuringiensis toxin Cry1Ac. J Econ Entomol 2010; 103:1821-1831. [PMID: 21061986 DOI: 10.1603/ec10087] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Evolution of resistance by pests can reduce the efficacy oftransgenic crops that produce insecticidal toxins from the bacterium Bacillus thuringiensis Berliner (Bt). In conjunction with refuges of non-Bt host plants, fitness costs can delay the evolution of resistance. Furthermore, fitness costs often vary with ecological conditions, suggesting that agricultural landscapes can be manipulated to magnify fitness costs and thereby prolong the efficacy of Bt crops. In the current study, we tested the effects of four species of entomopathogenic nematodes (Steinernematidae and Heterorhabditidae) on the magnitude and dominance of fitness costs of resistance to Bt toxin CrylAc in pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae). For more than a decade, field populations of pink bollworm in the United States have remained susceptible to Bt cotton Gossypium hirsutum L. producing CrylAc; however, we used laboratory strains that had a mixture of susceptible and resistant individuals. In laboratory experiments, dominant fitness costs were imposed by the nematode Steinernema riobrave Cabanillas, Poinar, and Raulston but no fitness costs were imposed by Steinernema carpocapsae Weiser, Steinernema sp. (ML18 strain), or Heterorhabditis sonorensis Stock, Rivera-Orduño, and Flores-Lara. In computer simulations, evolution of resistance to Cry1Ac by pink bollworm was substantially delayed by treating some non-Bt cotton refuge fields with nematodes that imposed a dominant fitness cost, similar to the cost observed in laboratory experiments with S. riobrave. Based on the results here and in related studies, we conclude that entomopathogenic nematodes could bolster insect resistance management, but the success of this approach will depend on selecting the appropriate species of nematode and environment, as fitness costs were magnified by only two of five species evaluated and also depended on environmental factors.
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Affiliation(s)
- Eugene R Hannon
- Department of Entomology, University of Arizona, Tucson, AZ 85721, USA
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Al-Mahrous M, Sandiford SK, Tagg JR, Upton M. Purification and characterization of a novel delta-lysin variant that inhibits Staphylococcus aureus and has limited hemolytic activity. Peptides 2010; 31:1661-8. [PMID: 20561552 DOI: 10.1016/j.peptides.2010.06.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Revised: 06/07/2010] [Accepted: 06/08/2010] [Indexed: 10/19/2022]
Abstract
Delta-lysins (DL) that are produced by various species of staphylococci are not widely known for their antimicrobial activity. We have purified and characterized a novel DL variant, E229DL and examined its spectrum of inhibitory activity. The biological activity of E229DL, produced by Staphylococcus epidermidis strain E229, shows relatively broad-spectrum activity against Gram-positive pathogens, including representatives of MRSA and epidemic MRSA type 15. E229DL was purified to homogeneity from 95% acidified-methanol extracts of cell cultures by using a series of reversed-phase chromatographic separations. The fully processed form of E229DL is a 25-amino-acid peptide with a predicted mass of 2841.4 Da, but the purified biologically active molecule appears to be N-formylated (mass 2867.33 Da). The DL gene (hld) resembles that of other types of DL, but differs in five codons with hld in Staphylococcus aureus (26 residues) and one codon with the closest homolog, the hld-II in S. warneri (25 residues). The characterization of E229DL showed that its activity is stable in agar exposed to high temperatures (80 degrees C/45 min). In addition, biological testing of the native and synthetic peptides against a range of human and animal erythrocytes and Vero cells indicated that E229DL is an antibacterial agent with no detectable cytopathic effects at concentrations equivalent to the minimum inhibitory concentration for EMRSA15-A208. Initial investigation of the mode of action of E229DL indicated that it is rapidly lytic for target cells. This is the first description of a native form of DL having only limited cytotoxic activity for eukaryotic cells at concentrations that are inhibitory to staphylococci.
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Affiliation(s)
- Mohammed Al-Mahrous
- Medical Microbiology, School of Translational Medicine, University of Manchester, Clinical Sciences Building, Manchester Royal Infirmary, Oxford Road, Manchester, M13 9WL, UK
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Nayak AP, Blachere FM, Hettick JM, Lukomski S, Schmechel D, Beezhold DH. Characterization of recombinant terrelysin, a hemolysin of Aspergillus terreus. Mycopathologia 2010; 171:23-34. [PMID: 20632211 DOI: 10.1007/s11046-010-9343-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2010] [Accepted: 06/29/2010] [Indexed: 11/26/2022]
Abstract
Fungal hemolysins are potential virulence factors. Some fungal hemolysins belong to the aegerolysin protein family that includes cytolysins capable of lysing erythrocytes and other cells. Here, we describe a hemolysin from Aspergillus terreus called terrelysin. We used the genome sequence database to identify the terrelysin sequence based on homology with other known aegerolysins. Aspergillus terreus mRNA was isolated, transcribed to cDNA and the open reading frame for terrelysin amplified by PCR using specific primers. Using the pASK-IBA6 cloning vector, we produced recombinant terrelysin (rTerrelysin) as a fusion product in Escherichia coli. The recombinant protein was purified and using MALDI-TOF MS determined to have a mass of 16,428 Da. Circular dichroism analysis suggests the secondary structure of the protein to be predominantly β-sheet. Results from thermal denaturation of rTerrelysin show that the protein maintained the β-sheet confirmation up to 65°C. Polyclonal antibody to rTerrelysin recognized a protein of approximately 16.5 kDa in mycelial extracts from A. terreus.
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Affiliation(s)
- Ajay P Nayak
- Allergy and Clinical Immunology Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, 1095 Willowdale Rd, Morgantown, WV 26505, USA
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Nguyen J, Russell SC. Targeted proteomics approach to species-level identification of Bacillus thuringiensis spores by AP-MALDI-MS. J Am Soc Mass Spectrom 2010; 21:993-1001. [PMID: 20236838 DOI: 10.1016/j.jasms.2010.01.032] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Revised: 01/28/2010] [Accepted: 01/28/2010] [Indexed: 05/28/2023]
Abstract
Anthrax infections progress at a rapid pace, making rapid detection methods of utmost importance. MALDI-MS proteomics methods focused on Bacillus anthracis detection have targeted chromosomally encoded proteins, which are highly conserved between closely related species, hindering species identification. Presented here is an AP-MALDI-MS method targeting plasmid-borne proteins from Bacillus spores for species-level identification. A bioinformatics analysis revealed that 60.3% and 75.4% of tryptic peptides from plasmid-borne proteins of B. anthracis and B. thuringiensis were species-specific, respectively. Reported here is a method in which plasmid-borne delta-endotoxins were extracted directly from B. thuringiensis spores in 100 mM KOH. The pH was then adjusted to 8 and a 5-min trypsin digestion was performed on the extracted proteins. The resulting tryptic peptides were analyzed by AP-MALDI-MS/MS, which produced a definitive identification the B. thuringiensis species-specific Cry1Ab protein with a MASCOT score of 278 and expect value of 7.5 x 10(-23). This method has demonstrated the detection and identification of B. thuringiensis spores at the species level following a 5-min trypsin digestion. The challenges in applying a similar approach to the detection of plasmid-borne protein toxins from B. anthracis are also discussed.
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Affiliation(s)
- Jennifer Nguyen
- Department of Chemistry, California State University, Stanislaus, Turlock, California 95382-0299, USA
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de Luis R, Lavilla M, Sánchez L, Calvo M, Pérez MD. Pepsin degradation of Cry1A(b) protein purified from genetically modified maize (Zea mays). J Agric Food Chem 2010; 58:2548-2553. [PMID: 20088594 DOI: 10.1021/jf903815s] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The aim of this work was to study the in vitro digestion of Cry1A(b) protein by pepsin. To perform this work, a protein fraction purified from transgenic maize by immunoadsorption was employed. The undigested fraction showed several bands of molecular weight ranging between 14 and 70 kDa when assayed by SDS-PAGE. These bands were identified as corresponding to Cry1A(b) protein by immunochemical techniques and mass spectrometry. The rate of degradation of the purified fraction by pepsin estimated by ELISA was found to be about 75% within 30 min, and the protein concentration remained constant up to 4 h. In all treated samples, the full-length protein and fragments present in Cry1A(b) fraction were absent and peptides of less than 8.5 kDa were mainly found by SDS-PAGE and mass spectrometry. These peptides did not react with antiserum against Cry1A(b) protein by Western blotting. These results suggest that Cry1A(b) fraction purified from transgenic maize is rapidly and extensively degraded by pepsin, giving peptides of low molecular mass.
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Affiliation(s)
- Ruth de Luis
- Tecnologia de los Alimentos, Facultad de Veterinaria, Universidad de Zaragoza, Miguel Servet, 177, 50013-Zaragoza, Spain
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Peng Y, Liu J, Li H, Huang Z, Li X, Yang W. [Studies on performance standard for hemolytic toxins in harmful bloom algae]. Wei Sheng Yan Jiu 2009; 38:653-656. [PMID: 20047215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
OBJECTIVE To explore a performance standard for hemolytic toxins in harmful bloom algae. METHODS Using Chattonella marina as hemolytic substances producing organism, methods and conditions were compared and optimized including cell breakage, distillation temperature, blood origin and storage of algal pellets in extraction and activity determination of hemolytic toxins. RESULTS The hemolytic activity of C. marina broken by supersonic method was 288.23 HU/L, higher than that by freezing--thawing method (94.89 HU/L), suggesting that supersonic method could be more optimal to break microalgal cells. When the supersonic treatment times were 5, 10, 20 and 30 min, the hemolytic activities were 80.57, 157.45, 288.23 and 279.17 HU/L, respectively, indicating that 20 min of supersonic treatment was suitable. When the distillation temperature were 40, 60 and 80 degrees C, the hemolytic activities were 288.23, 124.97 and 120.68 HU/L, respectively, meaning that high distillation temperature in extraction of hemolytic substances lowed the hemolytic activities of samples. Bloods from various animals such as human, fish, rat and rabbit exhibited different sensitivity to the hemolytic toxins, of which rabbit erythrocyte was the most sensitive. The hemolytic activities to human, fish, rat and rabbit were 244.98, 288.23, 266.35 and 195.47HU/L, respectively. The storage of algal pellets for 3 days at the temperature of 0 degrees C did not reveal a significant loss in hemolytic activity, while significant losses were observed at the temperature of 20 degrees C or -20 degrees C only after one day. CONCLUSION Supersonic method could be more optimal to break cell in comparison with freeze-thaw method. Optimal conditions for broken algal cells by supersonic method were 200 W for 20 min at the temperature of 4 degrees C. The distillation temperature in extraction of hemolytic substances should be maintained under the temperature of 40 degrees C. The rabbit erythrocyte could be the most optimal blood to detect hemolytic activity due to its high sensitivity. The algal pellets could be kept at the temperature of 0 degrees C for 3 days before determination of activity.
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Affiliation(s)
- Yinghui Peng
- School of Life Science and Technology, Jinan University, Guangzhou 510632, China
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Hire RS, Makde RD, Dongre TK, D'souza SF. Expression, purification and characterization of the Cry2Aa14 toxin from Bacillus thuringiensis subsp. kenyae. Toxicon 2009; 54:519-24. [PMID: 19486907 DOI: 10.1016/j.toxicon.2009.05.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Revised: 05/19/2009] [Accepted: 05/21/2009] [Indexed: 11/19/2022]
Abstract
An indigenous strain HD-550 of Bacillus thuringiensis subsp. kenyae was found to be toxic to lepidopteran as well as dipteran insects. The cry2Aa gene (classified as cry2Aa14) from this isolate was cloned and expressed in Escherichia coli. Only a little amount of the expressed Cry2Aa14 protein was observed in soluble fraction under normal induction condition. The inclusions were non-toxic to test insects, whereas solubilized Cry2Aa14 was highly toxic to lepidopteran and dipteran insects. Cry2Aa14 protein was expressed as thioredoxin (trx) fusion protein for improving the yield of active protein. An enhancement of nearly 15% was observed in the yield of active Cry2Aa14. The TrxA-Cry2Aa14 protein purified from the solubilized fraction also showed toxicity profile similar to the wild-type protein. The LC(50) values of Cry2Aa14 and TrxA-Cry2Aa14 protein against Spodoptera litura was 694 and 696 ng/cm(2), respectively, while for Culex quinquefasciatus the LC(50) values were 894 and 902 ng/ml, respectively. The broad spectrum toxicity of the Cry2Aa14 thus indicates that this protein could be an important component in integrated pest management. Further, the trx tag clearly led to higher yield, which facilitates protein purification for biophysical and biochemical characterization.
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Affiliation(s)
- Ramesh S Hire
- Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre (BARC), Trombay, Mumbai 400085, India
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Lv H, Kong Y, Yao Q, Zhang B, Leng FW, Bian HJ, Balzarini J, Van Damme E, Bao JK. Nebrodeolysin, a novel hemolytic protein from mushroom Pleurotus nebrodensis with apoptosis-inducing and anti-HIV-1 effects. Phytomedicine 2009; 16:198-205. [PMID: 18722099 DOI: 10.1016/j.phymed.2008.07.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2008] [Revised: 06/15/2008] [Accepted: 07/03/2008] [Indexed: 05/26/2023]
Abstract
A novel hemolysin was isolated from the edible mushroom Pleurotus nebrodensis by ion exchange and gel filtration chromatography on DEAE-Sepharose and Sephacryl S-100. The hemolysin from Pleurotus nebrodensis hemolysin (nebrodeolysin) is a monomeric protein with a molecular weight of approximately 27 kDa as determined by gel filtration and SDS-PAGE. Nebrodeolysin exhibited remarkable hemolytic activity towards rabbit erythrocytes and caused efflux of potassium ions from erythrocytes. Subsequently, this hemolysin showed strong cytotoxicity against Lu-04, Bre-04, HepG2, L929, and HeLa cells. It was also found that this hemolysin induced apoptosis in L929 and HeLa cells as evidenced by microscopic observations and DNA ladder, respectively. Moreover, this hemolysin was shown to possess anti-HIV-1 activity in CEM cell culture.
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Affiliation(s)
- Hui Lv
- College of Life Sciences, State Key Laboratory of Oral Diseases, Sichuan University, Chengdu 610064, China
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Zhang H, Yang H, Wang C, He H, Ma W, Yang S. [Activity and quality comparison of the engineered protein Staphylococcus aureus alpha-hemolysin purified with gel filtration chromatography and Ni-NTA]. Sheng Wu Gong Cheng Xue Bao 2009; 25:176-180. [PMID: 19459320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The alpha-hemolysin protein of Staphylococcus aureus, which was expressed in Escherichia coli BL21 (DE3) with recombinant pET32a(+)-alpha-HL plasmid, was purified with gel filtration chromatography (GFC) and Ni-NTA spin columns. The quality and biological characteristic were compared. First, the purified products were analyzed with SDS-PAGE, and the expected protein band was with a molecular mass of 53 kD. Second, protein concentration was determined by the method of Bradford, and the median hemolytic dose potency (HD50) was finally analyzed with rabbit erythrocyte. The protein purified with GFC was 0.337 mg/mL, its hemolysis activity was 1519 HU/mg, and hemolysin yield was 14.04%. Meanwhile, the protein purified with the Ni-NTA Spin Columns was 0.35 mg/mL, its hemolysis activity was 1463 HU/mg, and hemolysin yield was 17.5%, respectively. The results showed that there is no significant difference in the quality, hemolysis activity and yield of the recombinant proteins purified with Ni-NTA spin columns and GFC.
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Affiliation(s)
- Haiyan Zhang
- Cow Research Center, Agricultural Science Academy of Shandong Province, Jinan 250100, China
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Heatley NG. Unusual behaviour of a protein: reversible quantitative precipitation of staphylococcal delta-haemolysin by low concentrations of some organic solvents. Int J Pept Protein Res 2009; 8:233-6. [PMID: 6395 DOI: 10.1111/j.1399-3011.1976.tb02499.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Staphylococcal delta-haemolysin is precipitated from watery solutions by low concentrations of chloroform. The effect on this precipitation of pH, kind and concentration of salts, and concentration of, and time of exposure to, chloroform have been investigated. Some but not all of the other solvents tested cause a similar precipitation. The haemolytic activity is not destroyed and under appropriate conditions precipitation is quantitative. The dry lysin will take up nearly double its weight of chloroform when exposed to the vapour. Some is bound strongly.
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Halabi M, Orth D, Grif K, Wiesholzer-Pittl M, Kainz M, Schöberl J, Dierich MP, Allerberger F, Würzner R. Prevalence of Shiga toxin-, intimin- and haemolysin genes in Escherichia coli isolates from drinking water supplies in a rural area of Austria. Int J Hyg Environ Health 2008; 211:454-7. [PMID: 17889605 DOI: 10.1016/j.ijheh.2007.08.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2007] [Revised: 05/31/2007] [Accepted: 08/07/2007] [Indexed: 11/20/2022]
Abstract
Literature harbours several reports of potable water-associated outbreaks. We studied the prevalence of Shiga toxin- (stx1/2), intimin- (eae) and haemolysin (hlyA) genes in Escherichia coli isolates from drinking water of private and public water supplies in a rural area of Upper Austria; 2633 water samples were gained between November 2000 and December 2003. Two hundred and eighty of these water samples were positive for E. coli (10.6%). Of these, 101 samples were drawn from drilled wells (36%), 96 from dug wells (34%), 61 from springs (22%) and 22 from water supplies without available information on technical details (8%); 141 of the samples were from public water supplies, 139 from private water supplies. Eleven of the E. coli isolates were found to be positive for one of the investigated virulence genes (3.9%): one isolate yielded stx2, seven eae, and three isolates had hlyA. The presence of these genes underlines the importance of control of water quality in public and also private water supplies.
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Affiliation(s)
- Milad Halabi
- Department of Pathology and Microbiology, Krankenhaus der Barmherzigen Schwestern, Schlossberg 1, 4910 Ried im Innkreis, Austria.
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Wang H, Ye Q, Gan J, Wu J. Adsorption of Cry1Ab protein isolated from Bt transgenic rice on bentone, kaolin, humic acids, and soils. J Agric Food Chem 2008; 56:4659-4664. [PMID: 18512935 DOI: 10.1021/jf800162s] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Adsorption on a soil matrix of the insecticidal protein from Bacillus thuringiensis ( Bt) transgenic plants affects their accumulation and release and, hence, bioavailability in soil. Cry1Ab protein isolated from Bt transgenic rice was used to evaluate the adsorption and desorption on bentone, kaolin, and humic acids (HAs). The adsorption equilibrium of Cry1Ab protein was reached within 1-2 h for bentone and kaolin and within 4-8 h for HAs. The adsorption isotherms were better described by linear expressions ( R (2) >/= 0.973) rather than by the Freundlich model. No saturation was observed, even at the maximum concentration used (3.71 microg mL (-1)). The adsorbed protein was not easily desorbed at the used protein concentrations (0.18-3.71 microg mL (-1)); more than 50-70%, 70-80%, and 90% of the adsorbed protein remained on HAs, kaolin, and bentone, respectively, after washing with water. Adsorption and desorption of the Cry1Ab protein were further studied using five soils, and the isotherms were also well-described by linear equations ( p < 0.05). Adsorption of the Cry1Ab protein on soils was positively related to the soil organic matter content.
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Affiliation(s)
- Haiyan Wang
- Institute of Nuclear Agricultural Sciences, Zhejiang University, Huajiachi Campus, Hangzhou 310029, China
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Cohen S, Dym O, Albeck S, Ben-Dov E, Cahan R, Firer M, Zaritsky A. High-resolution crystal structure of activated Cyt2Ba monomer from Bacillus thuringiensis subsp. israelensis. J Mol Biol 2008; 380:820-7. [PMID: 18571667 DOI: 10.1016/j.jmb.2008.05.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2008] [Revised: 05/05/2008] [Accepted: 05/06/2008] [Indexed: 11/19/2022]
Abstract
The Cyt family of proteins consists of delta-endotoxins expressed during sporulation of several subspecies of Bacillus thuringiensis. Its members possess insecticidal, hemolytic, and cytolytic activities through pore formation and attract attention due to their potential use as vehicles for targeted membrane destruction. The delta-endotoxins of subsp. israelensis include three Cyt species: a major Cyt1Aa and two minor proteins, Cyt2Ba and Cyt1Ca. A cleaved Cyt protein that lacks the N- and C-terminal segments forms a toxic monomer. Here, we describe the crystal structure of Cyt2Ba, cleaved at its amino and carboxy termini by bacterial endogenous protease(s). Overall, its fold resembles that of the previously described volvatoxin A2 and the nontoxic form of Cyt2Aa. The structural similarity between these three proteins may provide information regarding the mechanism(s) of membrane-perforating toxins.
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Affiliation(s)
- Shmuel Cohen
- Department of Life Sciences, Ben-Gurion University of the Negev, POB 653, Be'er-Sheva 84105, Israel.
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Tan F, Zhu J, Li Y, Zheng A, Li P. [Identification, cloning and expression of the insecticidal protein genes from Bacillus thuringiensis isolate Rpp39]. Wei Sheng Wu Xue Bao 2008; 48:684-689. [PMID: 18652304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
OBJECTIVE We characterized strain Rpp39 isolated from the soil of Sichuan, China. A type of cry2Aa gene was cloned and expressed in E. coli. METHODS; We characterized strain Rpp39 by scanning electron microscope, PCR-RFLP identification and SDS-PAGE analysis. We cloned cry2Aa gene by PCR clone. We constructed the recombinant plasmid pET-2Aa, and transformed E.coli.BL21 (DE3) to express by IPTG. We determined the toxicity of expressed products to the larvae of Plutella xylostella and Chilo supperssalis through bioassay. RESULTS The strain Rpp39 contained three types parasporal crystals, diamond, squareness and round, observed under the scanning electron microscope. SDS-PAGE analysis showed that two kinds of molecular mass of insecticidal crystal proteins, one was about 130kD and the other 60 kDa, were expressed in isolate Rpp39. The strain contained cry1Aa, cry1Ab, cry1Ac, cry1Ia and cry2Aa gene, analyzed by the PCR-RFLP method. One cry2Aa-type gene of Rpp39 was cloned and designated as cry2Aa12 by Bacillus thuringiensis Insecticidal Crystal Proteins Nomenclature Committee. Sequence analysis revealed that this gene contained an open reading frame of 1902 nucleotides encoding a protein of 634 amino acids. Compared with Cry2Aa1 protein, Cry2Aa12 protein has shown as high as 99.7% amino acid homology. We amplified the full open reading frame sequence of the cry2Aa12 gene by use of a pair of PCR primers P3/P4 designed according to its DNA sequence, and the PCR product was inserted into the Nde I / BamH I site of E. coli expression vector pET-30a to obtain the recombinant plasmid pET-2Aa. The result of SDS-PAGE proved that Cry2Aa12 could be expressed as 65 kDa protein in E. coli BL21(DE3) strain induced by IPTG. We found that Cry2Aa12 was highly toxic to the larvae of Plutella xylostella and Chilo supperssalis through bioassay, with LC50 as 5.4 microg/mL and 22.3 microg/mL, respectively. CONCLUSION Strain Rpp39 and cry2Aa12 gene cloned from strain Rpp39 were came from Sichuan ecological condition in China. They could be affluent in the resources of strain and gene. It has important significance to accumulate the resource.
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Affiliation(s)
- Furong Tan
- Rice Research Institute, Sichuan Agricultural University, Wenjiang, Sichuan 611130.
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Zhu L, Li C, Wu J, Liang J, Shi Y. [Apoptosis of HL-60 cells induced by crystal proteins from Bacillus thuringiensis Bt9875]. Wei Sheng Wu Xue Bao 2008; 48:690-694. [PMID: 18652305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
OBJECTIVE To study the effect of Bt9875 crystal protein treated with proteinase K on human cancer cells, HL-60. METHODS We used the methods of Thiazolyl Blue Tetrazolium Bromide, fluorescence microscopy examination, agarose gel electrophores and flow cytometry to detect the growth inhibition rate and apoptosis characters of the HL-60 cells that were treated with different concentration of Bt9875 crystal protein. RESULTS Bt9875 crystal protein inhibited the growth of HL-60 cells evidently in a dose-dependent manner, with minimal effects on normal human peripheral blood mononuclear cells (PBMCs). The nuclei of HL-60 cells showed the characteristics of apoptosis. The analysis by flow cytometry indicated that the apoptosis rate of HL-60 cells was 52% after treatment with Bt9875 crystal protein (100 microg/mL). DNA analyzed by agarose gel electrophoresis showed "ladder" pattern. CONCLUSION Bt9875 crystal protein could inhibit the growth of HL-60 and induced its apoptosis, which provided a foundation for use of Bt9875 crystal protein to cure the acute myeloid leukemia.
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Affiliation(s)
- Lihong Zhu
- Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
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Razzolini MTP, Di Bari M, Sanchez PS, Sato MIZ. Aeromonas detection and their toxins from drinking water from reservoirs and drinking fountains. J Water Health 2008; 6:117-123. [PMID: 17998612 DOI: 10.2166/wh.2007.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Aeromonads are inhabitants of aquatic ecosystems and are described as being involved in intestinal disturbances and other infections. A total of 200 drinking water samples from domestic and public reservoirs and drinking fountains located in São Paulo (Brazil), were analyzed for the presence of Aeromonas. Samples were concentrated by membrane filtration and enriched in APW. ADA medium was used for Aeromonas isolation and colonies were confirmed by biochemical characterization. Strains isolated were tested for hemolysin and toxin production. Aeromonas was detected in 12 samples (6.0%). Aeromonas strains (96) were isolated and identified as: A. caviae (41.7%), A. hydrophila (15.7%), A.allosacharophila (10.4%), A. schubertii (1.0%) and Aeromonas spp. (31.2%). The results revealed that 70% of A. caviae, 66.7% of A. hydrophila, 80% of A. allosacharophila and 46.6% of Aeromonas spp. were hemolytic. The assay for checking production of toxins showed that 17.5% of A. caviae, 73.3% of A. hydrophila, 60% of A. allosacharophila, 100% of A. schubertii, and 33.3% of Aeromonas spp. were able to produce toxins. The results demonstrated the pathogenic potential of Aeromonas, indicating that the presence of this emerging pathogen in water systems is a public health concern.
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Yoshiike Y, Kayed R, Milton SC, Takashima A, Glabe CG. Pore-forming proteins share structural and functional homology with amyloid oligomers. Neuromolecular Med 2007; 9:270-5. [PMID: 17914185 DOI: 10.1007/s12017-007-0003-6] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2006] [Revised: 04/04/2007] [Accepted: 04/04/2007] [Indexed: 11/27/2022]
Abstract
Degenerative diseases such as Alzheimer's, Parkinson's, and Huntington's diseases are believed to be causally related to the accumulation of amyloid oligomers that exhibit a common structure and may be toxic by a common mechanism involving permeabilization of membranes. We discovered that amyloid oligomers and the pore-forming bacterial toxin, alpha-hemolysin (alpha HL), as well as human perforin from cytotoxic T lymphocytes, share a structural and functional homology at the level of their common reactivity with a conformation-dependent antibody that is specific for amyloid oligomers, A11. The alpha HL oligomeric pores and partially folded alpha HL protomer, but not the monomer alpha HL precursor reacts with A11 antibody. A11 antibody inhibits the hemolytic activity of alpha HL, indicating that the structural homology is functionally significant. Perforin oligomers were also recognized by A11. Amyloidogenic properties of alpha HL and perforin were confirmed spectroscopically and morphologically. These results indicate that pore forming proteins (PFP) and amyloid oligomers share structural homology and suggest that PFPs and amyloid oligomers share the same mechanism of membrane permeabilization.
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Affiliation(s)
- Yuji Yoshiike
- Laboratory for Alzheimer's Disease, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako-shi, Saitama, 351-0198, Japan
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Brinkman D, Burnell J. Partial purification of cytolytic venom proteins from the box jellyfish, Chironex fleckeri. Toxicon 2007; 51:853-63. [PMID: 18243272 DOI: 10.1016/j.toxicon.2007.12.017] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2007] [Revised: 12/11/2007] [Accepted: 12/14/2007] [Indexed: 11/17/2022]
Abstract
Venom proteins from the nematocysts of Chironex fleckeri were fractionated by size-exclusion and cation-exchange chromatography. Using sheep erythrocyte haemolysis as an indicator of cytolytic activity, two major cytolysins, with native molecular masses of approximately 370 and 145kDa, and one minor cytolysin ( approximately 70kDa) were isolated. SDS-PAGE and western blot protein profiles revealed that the 370kDa haemolysin is composed of CfTX-1 and CfTX-2 subunits ( approximately 43 and 45kDa, respectively); the most abundant proteins found in C. fleckeri nematocyst extracts. The 145kDa haemolysin predominately contains two other major proteins ( approximately 39 and 41kDa), which are not antigenic towards commercially available box jellyfish antivenom or rabbit polyclonal antibodies raised against whole C. fleckeri nematocyst extracts or CfTX-1 and -2. The kinetics of CfTX-1 and -2 haemolytic activities are temperature dependent and characterised by a pre-lytic lag phase ( approximately 6-7min) prior to initiation of haemolysis. Significant amino acid sequence homology between the CfTX proteins and other box jellyfish toxins suggest that CfTX-1 and -2 may also be lethal and dermonecrotic. Therefore, further in vivo and in vitro studies are required to investigate the potential roles of CfTX-1 and -2 in the lethal effects of C. fleckeri venom.
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Affiliation(s)
- Diane Brinkman
- Department of Biochemistry and Molecular Biology, School of Pharmacy and Molecular Sciences, James Cook University, Townsville, Qld 4811, Australia.
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Román Calderón ME, Alcocer González JM, Franco Molina MA, Tamez Guerra RS, Rodríguez Padilla C. Adjuvant effects of crystal proteins from a Mexican strain of Bacillus thuringiensis on the mouse humoral response. Biologicals 2007; 35:271-6. [PMID: 17408965 DOI: 10.1016/j.biologicals.2007.01.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2006] [Revised: 01/13/2007] [Accepted: 01/19/2007] [Indexed: 12/01/2022] Open
Abstract
In this study, we determined the adjuvant effects of the crystal (Cry) proteins, p130, p98, and p64-62, on the immune response of mice to both sheep red blood cells (SRBC) and ovalbumin (OVA). The administration of p130, p98, and p64-62 Cry proteins to Balb/c mice induced a significant (p<0.01) increase in the production of anti-SRBC antibody-secreting cells (ASC). The p64-62 Cry proteins demonstrated the best ability to induce the production of IgA and IgG antibodies to SRBC (p<0.05), and IgM, IgA, and IgG antibodies to OVA (p<0.05). Additionally, Cry proteins did not produce any side effects associated with their administration to Balb/c mice. We suggest the potential use of the p64-62 Cry proteins as adjuvants for the administration of heterologous antigens.
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Affiliation(s)
- Máximo E Román Calderón
- Laboratorio de Inmunología y Virología, Departamento de Microbiología e Inmunología, Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, San Nicolás de los Garza, Apartado Postal 46 "F", C.P. 66450, Nuevo León, Mexico
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Sauka DH, Basurto-Ríos ER, Ibarra JE, Benintende GB. [Insecticide proteic crystals from a native isolate of Bacillus thuringiensis]. Rev Argent Microbiol 2007; 39:225. [PMID: 18390157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023] Open
Affiliation(s)
- D H Sauka
- Area Bioinsumos Microbianos, IMYZA-INTA, De los Reseros y Las Cabañas, Castelar, Buenos Aires, Argentina.
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Vanberg C, Lutnaes BF, Langsrud T, Nes IF, Holo H. Propionibacterium jensenii produces the polyene pigment granadaene and has hemolytic properties similar to those of Streptococcus agalactiae. Appl Environ Microbiol 2007; 73:5501-6. [PMID: 17630313 PMCID: PMC2042088 DOI: 10.1128/aem.00545-07] [Citation(s) in RCA: 20] [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: 11/20/2022] Open
Abstract
The red polyene pigment granadaene was purified and identified from Propionibacterium jensenii. Granadaene has previously been identified only in Streptococcus agalactiae, where the pigment correlates with the hemolytic activity of the bacterium. A connection between hemolytic activity and the production of the red pigment has also been observed in P. jensenii, as nonpigmented strains are nonhemolytic. The pigment and hemolytic activity from S. agalactiae can be extracted from the bacterium with a starch extraction solution, and this solution also extracts the pigment and hemolytic activity from P. jensenii. A partial purification of the hemolytic activity was achieved, but the requirement for starch to preserve its activity made the purification unsuccessful. Partially purified hemolytic fractions were pigmented, and the color intensity of the fractions coincided with the hemolytic titer. The pigment was produced in a soluble form when associated with starch, and the UV-visual spectrum of the extract gave absorption peaks of 463 nm, 492 nm, and 524 nm. The pigment could also be extracted from the cells by a low-salt buffer, but it was then aggregated. The purification of the pigment from P. jensenii was performed, and mass spectrometry and nuclear magnetic resonance analysis revealed that P. jensenii indeed produces granadaene as seen in S. agalactiae.
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Affiliation(s)
- Christin Vanberg
- Laboratory of Microbial Gene Technology and Food Microbiology, Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, N-1432 As, Norway.
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Huang KX, Badger M, Haney K, Evans SL. Large scale production of Bacillus thuringiensis PS149B1 insecticidal proteins Cry34Ab1 and Cry35Ab1 from Pseudomonas fluorescens. Protein Expr Purif 2007; 53:325-30. [PMID: 17337206 DOI: 10.1016/j.pep.2007.01.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2006] [Revised: 01/16/2007] [Accepted: 01/16/2007] [Indexed: 11/18/2022]
Abstract
The 14kDa (Cry34Ab1) and 44kDa (Cry35Ab1) binary insecticidal proteins are produced naturally by Bacillus thuringiensis PS149B1 as parasporal inclusion bodies. Here, we show production of these two insecticidal proteins in recombinant Pseudomonas fluorescens and their subsequent purification to near homogeneity to provide large quantities of protein for safety-assessment studies associated with the registration of transgenic corn plants. The gene sequence specific for each protein was expressed in P. fluorescens and fermented at the 75-L scale. For Cry34Ab1, the protein accumulated as insoluble inclusion bodies, and was purified by extraction directly from the cell pastes at pH 3.4 with a sodium acetate buffer, selective precipitation at pH 7.0, and differential centrifugation. For Cry35Ab1, the protein was extracted from the purified inclusion bodies with sodium acetate buffer (pH 3.5) containing 0.5M urea, followed by diafiltration. No chromatography steps were required to produce over 30g of lyophilized protein powder with purity greater than 98%, while retaining full insecticidal activity against Western corn rootworm larvae. The proteins were further characterized to assure identity and suitability for use in safety-assessment studies.
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Affiliation(s)
- Ke-Xue Huang
- Dow AgroSciences LLC, 9330 Zionsville Road, Indianapolis, IN 46268, USA.
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Yang YK, Cai QX, Cai YJ, Yan JP, Yuan ZM. [The synergism between Mtx1 from Bacillus sphaericus and Cyt1 Aa from Bacillus thuringiensis to Culex quinquefasciatus]. Wei Sheng Wu Xue Bao 2007; 47:456-60. [PMID: 17672305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Mosquitocidal toxin 1 (Mtx1) was synthesized during vegetative phase of Bacillus sphaericus and it had been proved to have higher activity to Aedes spp. larvae and Binary toxin (Bin) resistance Culex larvae. The truncated 97 kDa Mtx1 with a deletion of the signal peptide and the Cyt1 Aa crystal protein, a 27.3 kDa delta-endotoxin from Bacillus thuringiensis subsp. israelensis (Bti), were purified from Escherichia coli and B. thuringiensis recombinant strains respectively. Both purified toxins had high toxicity against Culex quinquefasciatus larvae. Bioassay result revealed the purified Mtx1 toxin had high toxicity against the target mosquito larvae, with LCso of 45.2 ng/mL. However, the mixture of Mtx1 and Cytl Aa exhibited higher toxicity against the mosquito larvae, with a lowest LC50 value of 20.19 ng/mL at the ratio of 1:3. (Mtx1:Cyt1 Aa). The calculated synergistic factor of different mixtures suggested a strong synergistic effect between Cyt1 Aa toxin and Mtx1. Furthermore, the presence of Cyt1Aa in the mixture could induce early larval mortality, enhancing the activity of Mtx1 to the target mosquito larvae. The synergistic effect of Cyt1 Aa on mortality of Mtx1 to mosquito larvae might be caused by the damage of the larval midgut-hemocoel barrier induced by the activated CytlAa toxin, which enhanced the specific pathogenesis of Mtx1 on mosquito larvae. It is suggested that the co-application of Mtx1 and Cyt1 Aa in future will be integrated for mosquito management.
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Affiliation(s)
- Yan-kun Yang
- Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China.
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Schaufuss P, Müller F, Valentin-Weigand P. Isolation and characterization of a haemolysin from Trichophyton mentagrophytes. Vet Microbiol 2007; 122:342-9. [PMID: 17336469 DOI: 10.1016/j.vetmic.2007.01.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2006] [Revised: 01/21/2007] [Accepted: 01/23/2007] [Indexed: 11/23/2022]
Abstract
Haemolytic activities of Trichophyton (T.) mentagrophytes were detected and characterized by qualitative and quantitative assays. On Columbia agar supplemented with blood from horses, cattle or sheep, T. mentagrophytes expressed a strong zone of complete haemolysis. No haemolytic activities could be detected in the closely related T. verrucosum var. ochraceum. The same results were obtained after cultivation of the fungi on sterile cellulose acetate filters placed on the surface on Columbia blood agar. After removal of the filter, complete haemolysis was detected below the colony of T. mentagrophytes. A soluble haemolysin from culture supernatant of this strain was isolated and partially purified. Specific haemolytic activity per mg protein was enriched 2.6-fold in filtrate F(1), a fraction obtained as filtrate after filtration through 3kDa cut-off membranes. The partially purified haemolysin was neither affected by proteinase K treatment, nor by high and low temperatures, suggesting that it represents a small peptide haemolysin. Accordingly, in a commercial enzymatic activity test only the crude culture filtrate, but none of the subsequent purification fractions showed reactivity. Evaluation of the specificity of the haemolysin using erythrocytes from different mammalian species revealed that sensitivity was highest to those of equines, followed by erythrocytes from sheep, cattle, swine, dogs and humans. None of the erythrocytes was lysed by filtrate F(1) from T. verrucosum var. ochraceum. Furthermore, different eukaryotic cell lines from different species were tested in their sensitivity to cytolytic activities of the haemolysin, but no membrane damage could be detected.
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Affiliation(s)
- P Schaufuss
- Serumwerk Memsen WDT, Memsen 13, Hoyerhagen, Germany.
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Chayaratanasin P, Moonsom S, Sakdee S, Chaisri U, Katzenmeier G, Angsuthanasombat C. High level of soluble expression in Escherichia coli and characterisation of the cloned Bacillus thuringiensis Cry4Ba domain III fragment. BMB Rep 2007; 40:58-64. [PMID: 17244483 DOI: 10.5483/bmbrep.2007.40.1.058] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [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] Open
Abstract
Similar to the other known structures of Bacillus thuringiensis Cry delta-endotoxins, the crystal structure of the 65-kDa activated Cry4Ba toxin comprises three domains which are, from the N- to C-terminus, a bundle of alpha-helices, a three-beta-sheet domain, and a beta-sandwich. To investigate the properties of the C-terminal domain III in isolation from the rest of the toxin, the cloned Cry4Ba-domain III was over-expressed as a 21-kDa soluble protein in Escherichia coli, which cross-reacted with anti-Cry4Ba domain III monoclonal antibody. A highly-purified domain III was obtained in a monomeric form by ion-exchange and size-exclusion FPLC. Circular dichroism spectroscopy indicated that the isolated domain III fragment distinctly exists as a beta-sheet structure, corresponding to the domain III structure embodied in the Cry4Ba crystal structure. In vitro binding analysis via immuno-histochemical assay revealed that the Cry4Ba-domain III protein was able to bind to the apical microvilli of the susceptible Stegomyia aegypti larval midguts, albeit at lower-binding activity when compared with the full-length active toxin. These results demonstrate for the first time that the C-terminal domain III of the Cry4Ba mosquito-larvicidal protein, which can be isolated as a native folded monomer, conceivably participates in toxin-receptor recognition.
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Affiliation(s)
- Poramed Chayaratanasin
- Laboratory of Molecular Biophysics and Structural Biochemistry, Institute of Molecular Biology and Genetics, Mahidol University, Salaya Campus, Nakornpathom 73170, Thailand
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