Detection of Ganglioside-Specific Toxin Binding with Biomembrane-Based Bioelectronic Sensors

2021 ◽  
Author(s):  
Samavi Farnush Bint E Naser ◽  
Hui Su ◽  
Han-Yuan Liu ◽  
Zachary A. Manzer ◽  
Zhongmou Chao ◽  
...  
Keyword(s):  
Toxin Binding

Scorpion toxin-potassium channel interaction law and its applications.

2020 ◽  
Vol 01 ◽  
Author(s):  
Zheng Zuo ◽  
Zongyun Chen ◽  
Zhijian Cao ◽  
Wenxin Li ◽  
Yingliang Wu
Keyword(s):  
Potassium Channel ◽  
Scorpion Toxin ◽  
Scorpion Toxins ◽  
Toxin Binding ◽  
Channel Interaction ◽  
Binding Interface ◽  
Α Helix ◽  
Interaction Law ◽  
Binding Interfaces ◽  
Β Sheet

: The scorpion toxins are the largest potassium channel-blocking peptide family. The understanding of toxin binding interfaces is usually restricted by two classical binding interfaces: one is the toxin α-helix motif, the other is the antiparallel β-sheet motif. In this review, such traditional knowledge was updated by another two different binding interfaces: one is BmKTX toxin using the turn motif between the α-helix and antiparallel β-sheet domains as the binding interface, the other is Ts toxin using turn motif between the β-sheet in the N-terminal and α-helix domains as the binding interface. Their interaction analysis indicated that the scarce negatively charged residues in the scorpion toxins played a critical role in orientating the toxin binding interface. In view of the toxin negatively charged amino acids as “binding interface regulator”, the law of scorpion toxin-potassium channel interaction was proposed, that is, the polymorphism of negatively charged residue distribution determines the diversity of toxin binding interfaces. Such law was used to develop scorpion toxin-potassium channel recognition control technique. According to this technique, three Kv1.3 channel-targeted peptides, using BmKTX as the template, were designed with the distinct binding interfaces from that of BmKTX through modulating the distribution of toxin negatively charged residues. In view of the potassium channel as the common targets of different animal toxins, the proposed law was also shown to helpfully orientate the binding interfaces of other animal toxins. Clearly, the toxin-potassium channel interaction law would strongly accelerate the research and development of different potassium channelblocking animal toxins in the future.

scholarly journals Liposomes Prevent In Vitro Hemolysis Induced by Streptolysin O and Lysenin

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 364
Author(s):  
Marcelo Ayllon ◽  
Gamid Abatchev ◽  
Andrew Bogard ◽  
Rosey Whiting ◽  
Sarah E. Hobdey ◽  
...  
Keyword(s):  
Blood Cell ◽  
Lipid Membranes ◽  
Bilayer Lipid Membranes ◽  
Prior Work ◽  
Cellular Targets ◽  
Toxin Binding ◽  
Streptolysin O ◽  
Biological Attack ◽  
Toxin Removal

The need for alternatives to antibiotics in the fight against infectious diseases has inspired scientists to focus on antivirulence factors instead of the microorganisms themselves. In this respect, prior work indicates that tiny, enclosed bilayer lipid membranes (liposomes) have the potential to compete with cellular targets for toxin binding, hence preventing their biological attack and aiding with their clearance. The effectiveness of liposomes as decoy targets depends on their availability in the host and how rapidly they are cleared from the circulation. Although liposome PEGylation may improve their circulation time, little is known about how such a modification influences their interactions with antivirulence factors. To fill this gap in knowledge, we investigated regular and long-circulating liposomes for their ability to prevent in vitro red blood cell hemolysis induced by two potent lytic toxins, lysenin and streptolysin O. Our explorations indicate that both regular and long-circulating liposomes are capable of similarly preventing lysis induced by streptolysin O. In contrast, PEGylation reduced the effectiveness against lysenin-induced hemolysis and altered binding dynamics. These results suggest that toxin removal by long-circulating liposomes is feasible, yet dependent on the particular virulence factor under scrutiny.

Anti-human HB-EGF monoclonal antibodies inhibiting ectodomain shedding of HB-EGF and diphtheria toxin binding

2010 ◽  
Vol 148 (1) ◽  
pp. 55-69 ◽  
Author(s):  
M. Hamaoka ◽  
I. Chinen ◽  
T. Murata ◽  
S. Takashima ◽  
R. Iwamoto ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Diphtheria Toxin ◽  
Ectodomain Shedding ◽  
Toxin Binding

scholarly journals Annexin A2 Mediates Mycoplasma pneumoniae Community-Acquired Respiratory Distress Syndrome Toxin Binding to Eukaryotic Cells

mBio ◽  
2014 ◽  
Vol 5 (4) ◽  
Author(s):  
Sudha R. Somarajan ◽  
Fadi Al-Asadi ◽  
Kumaraguruparan Ramasamy ◽  
Lavanya Pandranki ◽  
Joel B. Baseman ◽  
...  
Keyword(s):  
Respiratory Distress Syndrome ◽  
Respiratory Distress ◽  
Mammalian Cells ◽  
Distress Syndrome ◽  
Protein A ◽  
A549 Cells ◽  
Surfactant Protein ◽  
Annexin A2 ◽  
Toxin Binding ◽  
Cards Toxin

ABSTRACT Mycoplasma pneumoniae synthesizes a novel human surfactant protein A (SP-A)-binding cytotoxin, designated community-acquired respiratory distress syndrome (CARDS) toxin, that exhibits ADP-ribosylating and vacuolating activities in mammalian cells and is directly linked to a range of acute and chronic airway diseases, including asthma. In our attempt to detect additional CARDS toxin-binding proteins, we subjected the membrane fraction of human A549 airway cells to affinity chromatography using recombinant CARDS toxin as bait. A 36-kDa A549 cell membrane protein bound to CARDS toxin and was identified by time of flight (TOF) mass spectroscopy as annexin A2 (AnxA2) and verified by immunoblotting with anti-AnxA2 monoclonal antibody. Dose-dependent binding of CARDS toxin to recombinant AnxA2 reinforced the specificity of the interaction, and further studies revealed that the carboxy terminus of CARDS toxin mediated binding to AnxA2. In addition, pretreatment of viable A549 cells with anti-AnxA2 monoclonal antibody or AnxA2 small interfering RNA (siRNA) reduced toxin binding and internalization. Immunofluorescence analysis of CARDS toxin-treated A549 cells demonstrated the colocalization of CARDS toxin with cell surface-associated AnxA2 upon initial binding and with intracellular AnxA2 following toxin internalization. HepG2 cells, which express low levels of AnxA2, were transfected with a plasmid expressing AnxA2 protein, resulting in enhanced binding of CARDS toxin and increased vacuolization. In addition, NCI-H441 cells, which express both AnxA2 and SP-A, upon AnxA2 siRNA transfection, showed decreased binding and subsequent vacuolization. These results indicate that CARDS toxin recognizes AnxA2 as a functional receptor, leading to CARDS toxin-induced changes in mammalian cells. IMPORTANCE Host cell susceptibility to bacterial toxins is usually determined by the presence and abundance of appropriate receptors, which provides a molecular basis for toxin target cell specificities. To perform its ADP-ribosylating and vacuolating activities, community-acquired respiratory distress syndrome (CARDS) toxin must bind to host cell surfaces via receptor-mediated events in order to be internalized and trafficked effectively. Earlier, we reported the binding of CARDS toxin to surfactant protein A (SP-A), and here we show how CARDS toxin uses an alternative receptor to execute its pathogenic properties. CARDS toxin binds selectively to annexin A2 (AnxA2), which exists both on the cell surface and intracellularly. Since AnxA2 regulates membrane dynamics at early stages of endocytosis and trafficking, it serves as a distinct receptor for CARDS toxin binding and internalization and enhances CARDS toxin-induced vacuolization in mammalian cells.

Different frequencies of memory B-cells induced by tetanus, botulinum, and heat-labile toxin binding domains

2019 ◽  
Vol 127 ◽  
pp. 225-232 ◽  
Author(s):  
Ehsan Rezaie ◽  
Hekmat Nekoie ◽  
Ali Miri ◽  
Gholamreza Oulad ◽  
Ali Ahmadi ◽  
...  
Keyword(s):  
B Cells ◽  
Memory B Cells ◽  
Toxin Binding ◽  
Binding Domains ◽  
Heat Labile

scholarly journals Improved Specificity of a Multiplex Immunoassay for Quantitation of Anti-Diphtheria Toxin Antibodies with the Use of Diphtheria Toxoid

2011 ◽  
Vol 18 (7) ◽  
pp. 1183-1186 ◽  
Author(s):  
Pieter G. M. van Gageldonk ◽  
Christina von Hunolstein ◽  
Fiona R. M. van der Klis ◽  
Guy A. M. Berbers
Keyword(s):  
Diphtheria Toxin ◽  
Neutralization Test ◽  
Diphtheria Toxoid ◽  
Inhibition Assay ◽  
Nonspecific Binding ◽  
Serum Samples ◽  
Multiplex Immunoassay ◽  
Toxin Binding ◽  
Binding Inhibition ◽  
Binding Inhibition Assay

ABSTRACTA nonspecific binding of antibodies to diphtheria toxin, especially in adult serum samples, was observed in our diphtheria-tetanus-pertussis multiplex immunoassay (DTaP4 MIA). This can be significantly reduced by the use of diphtheria toxoid, achieving a good correlation with the Vero cell neutralization test and the toxin binding inhibition assay.

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