Dataset Information

Strong Inhibition of Cholera Toxin B Subunit by Affordable, Polymer-Based Multivalent Inhibitors.

ABSTRACT: Cholera is a potentially fatal bacterial infection that affects a large number of people in developing countries. It is caused by the cholera toxin (CT), an AB₅ toxin secreted by Vibrio cholera. The toxin comprises a toxic A-subunit and a pentameric B-subunit that bind to the intestinal cell surface. Several monovalent and multivalent inhibitors of the toxin have been synthesized but are too complicated and expensive for practical use in developing countries. Meta-nitrophenyl ?-galactoside (MNPG) is a known promising ligand for CT, and here mono- and multivalent compounds based on MNPG were synthesized. We present the synthesis of MNPG in greatly improved yields and its use while linked to a multivalent scaffold. We used economical polymers as multivalent scaffolds, namely, polyacrylamide, dextran, and hyperbranched polyglycerols (hPGs). Copper-catalyzed alkyne azide cycloaddition reaction (CuAAC) produced the inhibitors that were tested in an ELISA-type assay and an intestinal organoid swelling inhibition assay. The inhibitory properties varied widely depending on the type of polymer, and the most potent conjugates showed IC₅₀ values in the nanomolar range.

SUBMITTER: Haksar D

PROVIDER: S-EPMC6429436 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Strong Inhibition of Cholera Toxin B Subunit by Affordable, Polymer-Based Multivalent Inhibitors.

Haksar Diksha D de Poel Eyleen E van Ufford Linda Quarles LQ Bhatia Sumati S Haag Rainer R Beekman Jeffrey J Pieters Roland J RJ

Bioconjugate chemistry 20190124 3

Cholera is a potentially fatal bacterial infection that affects a large number of people in developing countries. It is caused by the cholera toxin (CT), an AB<sub>5</sub> toxin secreted by Vibrio cholera. The toxin comprises a toxic A-subunit and a pentameric B-subunit that bind to the intestinal cell surface. Several monovalent and multivalent inhibitors of the toxin have been synthesized but are too complicated and expensive for practical use in developing countries. Meta-nitrophenyl α-galact ...[more]

PMID: 30629410

Similar Datasets

Project description:IntroductionCholera toxin B subunit (CTB) is a component of an internationally licensed oral cholera vaccine. The protein induces neutralizing antibodies against the holotoxin, the virulence factor responsible for severe diarrhea. A field clinical trial has suggested that the addition of CTB to killed whole-cell bacteria provides superior short-term protection to whole-cell-only vaccines; however, challenges in CTB biomanufacturing (i.e., cost and scale) hamper its implementation to mass vaccination in developing countries. To provide a potential solution to this issue, we developed a rapid, robust, and scalable CTB production system in plants.Methodology/principal findingsIn a preliminary study of expressing original CTB in transgenic Nicotiana benthamiana, the protein was N-glycosylated with plant-specific glycans. Thus, an aglycosylated CTB variant (pCTB) was created and overexpressed via a plant virus vector. Upon additional transgene engineering for retention in the endoplasmic reticulum and optimization of a secretory signal, the yield of pCTB was dramatically improved, reaching >1 g per kg of fresh leaf material. The protein was efficiently purified by simple two-step chromatography. The GM1-ganglioside binding capacity and conformational stability of pCTB were virtually identical to the bacteria-derived original B subunit, as demonstrated in competitive enzyme-linked immunosorbent assay, surface plasmon resonance, and fluorescence-based thermal shift assay. Mammalian cell surface-binding was corroborated by immunofluorescence and flow cytometry. pCTB exhibited strong oral immunogenicity in mice, inducing significant levels of CTB-specific intestinal antibodies that persisted over 6 months. Moreover, these antibodies effectively neutralized the cholera holotoxin in vitro.Conclusions/significanceTaken together, these results demonstrated that pCTB has robust producibility in Nicotiana plants and retains most, if not all, of major biological activities of the original protein. This rapid and easily scalable system may enable the implementation of pCTB to mass vaccination against outbreaks, thereby providing better protection of high-risk populations in developing countries.

Dataset Information

Strong Inhibition of Cholera Toxin B Subunit by Affordable, Polymer-Based Multivalent Inhibitors.

Publications

Strong Inhibition of Cholera Toxin B Subunit by Affordable, Polymer-Based Multivalent Inhibitors.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets