Toxins

593 KiB

Open AccessCommunication

Detection of Fumonisin B1 and Ochratoxin A in Grain Products Using Microsphere-Based Fluid Array Immunoassays

by George P. Anderson, Vasudha A. Kowtha and Chris R. Taitt

Toxins 2010, 2(2), 297-309; https://doi.org/10.3390/toxins2020297 - 25 Feb 2010

Cited by 39 | Viewed by 10607

Grain products are a staple of diets worldwide and therefore, the ability to accurately and efficiently detect foodborne contaminants such as mycotoxins is of importance to everyone. Here we describe an indirect competitive fluid array fluoroimmunoassay to quantify the mycotoxins, fumonisin B1 and ochratoxin A. Both toxins were immobilized to the surface of microspheres using a variety of intermediate molecules and binding of biotinylated "tracer" antibody tracers determined through flow cytometry using streptavidin-phycoerythrin conjugates and the Luminex100 flow cytometer. Competitive assays were developed where the binding of biotinylated monoclonal antibodies to fumonisin B and ochratoxin A was competitively inhibited by different concentrations of those toxins in solution. Concentrations of fumonisin giving 50% inhibition were 300 pg/mL in buffer, 100 ng/g in spiked oats, and 1 μg/g in spiked cornmeal; analogous concentrations for ochratoxin A were 30 ng/mL in buffer, 30 ng/g in spiked oats, and 10 ng/g in spiked corn. The future challenge will be to expand the number of mycotoxins tested both individually and in multiplexed format using this platform. Full article

(This article belongs to the Special Issue Advances in Mycotoxin Research)

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226 KiB

Open AccessArticle

Escherichia coli Cytotoxic Necrotizing Factor 1 (CNF1): Toxin Biology, in Vivo Applications and Therapeutic Potential

by Alessia Fabbri, Sara Travaglione and Carla Fiorentini

Toxins 2010, 2(2), 283-296; https://doi.org/10.3390/toxins2020282 - 23 Feb 2010

Cited by 47 | Viewed by 11881

Abstract

CNF1 is a protein toxin produced by certain pathogenic strains of Escherichia coli. It permanently activates the regulatory Rho, Rac, and Cdc42 GTPases in eukaryotic cells, by deamidation of a glutamine residue. This modification promotes new activities in cells, such as gene transcription, cell proliferation and survival. Since the Rho GTPases play a pivotal role also in several processes in vivo, the potentiality of CNF1 to act as a new pharmacological tool has been explored in experimental animals and in diverse pathological contexts. In this review, we give an update overview on the potential in vivo applications of CNF1. Full article

(This article belongs to the Special Issue Bacterial Protein Toxins)

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648 KiB

Open AccessReview

Animal Toxins: How is Complexity Represented in Databases?

by Florence Jungo, Anne Estreicher, Amos Bairoch, Lydie Bougueleret and Ioannis Xenarios

Toxins 2010, 2(2), 262-282; https://doi.org/10.3390/toxins2020261 - 21 Feb 2010

Cited by 14 | Viewed by 13286

Abstract

Peptide toxins synthesized by venomous animals have been extensively studied in the last decades. To be useful to the scientific community, this knowledge has been stored, annotated and made easy to retrieve by several databases. The aim of this article is to present what type of information users can access from each database. ArachnoServer and ConoServer focus on spider toxins and cone snail toxins, respectively. UniProtKB, a generalist protein knowledgebase, has an animal toxin-dedicated annotation program that includes toxins from all venomous animals. Finally, the ATDB metadatabase compiles data and annotations from other databases and provides toxin ontology. Full article

(This article belongs to the Special Issue Animal Venoms)

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908 KiB

Open AccessReview

Mycotoxin Contamination of Beverages: Occurrence of Patulin in Apple Juice and Ochratoxin A in Coffee, Beer and Wine and Their Control Methods

by Kasa R. N. Reddy, Hamed K. Abbas, Craig A. Abel, Wayne Thomas Shier and Baharuddin Salleh

Toxins 2010, 2(2), 229-261; https://doi.org/10.3390/toxins2020229 - 2 Feb 2010

Cited by 14 | Viewed by 11349 | Retraction

Abstract

It has been brought to our attention by a member of our Editorial Board that substantial portions of this review article have been copied verbatim from earlier publications without credit. After comparing the present paper and the other sources we have determined that indeed this manuscript clearly violates our policy on originality of all material submitted for publication and the generally accepted ethics of scientific publication. Consequently, the Editorial Team and Publisher have determined that it should be retracted. We apologize for any inconvenience this may cause. Full article

(This article belongs to the Special Issue Advances in Mycotoxin Research)

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Open AccessReview

Escherichia coli Subtilase Cytotoxin

by Adrienne W. Paton and James C. Paton

Toxins 2010, 2(2), 215-228; https://doi.org/10.3390/toxins2020215 - 28 Jan 2010

Cited by 45 | Viewed by 12268

Abstract

Subtilase cytotoxin (SubAB) is the prototype of a new AB₅ toxin family produced by a subset of Shiga toxigenic Escherichia coli (STEC) strains. Its A subunit is a subtilase-like serine protease and cytotoxicity for eukaryotic cells is due to a highly specific, single-site cleavage of BiP/GRP78, an essential Hsp70 family chaperone located in the endoplasmic reticulum (ER). This cleavage triggers a severe and unresolved ER stress response, ultimately triggering apoptosis. The B subunit has specificity for glycans terminating in the sialic acid N-glycolylneuraminic acid. Although its actual role in human disease pathogenesis is yet to be established, SubAB is lethal for mice and induces pathological features overlapping those seen in the haemolytic uraemic syndrome, a life-threatening complication of STEC infection. The toxin is also proving to be a useful tool for probing the role of BiP and ER stress in a variety of cellular functions. Full article

(This article belongs to the Special Issue Bacterial Protein Toxins)

991 KiB

Open AccessReview

Pasteurella multocida Toxin Activates Various Heterotrimeric G Proteins by Deamidation

by Joachim H. C. Orth and Klaus Aktories

Toxins 2010, 2(2), 205-214; https://doi.org/10.3390/toxins2020205 - 28 Jan 2010

Cited by 21 | Viewed by 11861

Abstract

Pasteurella multocida produces a 146-kDa protein toxin (Pasteurella multocida toxin, PMT), which stimulates diverse cellular signal transduction pathways by activating heterotrimeric G proteins. PMT deamidates a conserved glutamine residue of the α-subunit of heterotrimeric G proteins that is essential for GTP-hydrolysis, thereby arresting the G protein in the active state. The toxin substrates are Gα_q Gα₁₃ and the Gα_i-family proteins. Activation of these α-subunits causes stimulation of phospholipase Cβ, Rho-guanine nucleotide exchange factors or inhibition of adenylyl cyclase. This article provides the current knowledge on PMT concerning the structure-function analysis based on the crystal structure and recently elucidated molecular mode of action. Furthermore, the impact of PMT on cellular signaling is discussed. Full article

(This article belongs to the Special Issue Bacterial Protein Toxins)

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Toxins, Volume 2, Issue 2 (February 2010) – 6 articles , Pages 205-309

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