Back to Search
Start Over
Intracellular Neutralization of Ricin Toxin by Single-domain Antibodies Targeting the Active Site.
- Source :
-
Journal of molecular biology [J Mol Biol] 2020 Feb 14; Vol. 432 (4), pp. 1109-1125. Date of Electronic Publication: 2020 Jan 10. - Publication Year :
- 2020
-
Abstract
- The extreme potency of the plant toxin, ricin, is due to its enzymatic subunit, RTA, which inactivates mammalian ribosomes with near-perfect efficiency. Here we characterized, at the functional and structural levels, seven alpaca single-domain antibodies (V <subscript>H</subscript> Hs) previously reported to recognize epitopes in proximity to RTA's active site. Three of the V <subscript>H</subscript> Hs, V2A11, V8E6, and V2G10, were potent inhibitors of RTA in vitro and protected Vero cells from ricin when expressed as intracellular antibodies ("intrabodies"). Crystal structure analysis revealed that the complementarity-determining region 3 (CDR3) elements of V2A11 and V8E6 penetrate RTA's active site and interact with key catalytic residues. V2G10, by contrast, sits atop the enzymatic pocket and occludes substrate accessibility. The other four V <subscript>H</subscript> Hs also penetrated/occluded RTA's active site, but lacked sufficient binding affinities to outcompete RTA-ribosome interactions. Intracellular delivery of high-affinity, single-domain antibodies may offer a new avenue in the development of countermeasures against ricin toxin.toxin, antibody, structure, intracellular.<br /> (Copyright © 2020 Elsevier Ltd. All rights reserved.)
- Subjects :
- Animals
Antibodies, Neutralizing metabolism
Binding Sites, Antibody
Catalytic Domain
Chlorocebus aethiops
Enzyme-Linked Immunosorbent Assay
Polymerase Chain Reaction
Single-Domain Antibodies metabolism
Surface Plasmon Resonance
Vero Cells
Antibodies, Neutralizing immunology
Ricin chemistry
Ricin immunology
Single-Domain Antibodies immunology
Subjects
Details
- Language :
- English
- ISSN :
- 1089-8638
- Volume :
- 432
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- Journal of molecular biology
- Publication Type :
- Academic Journal
- Accession number :
- 31931008
- Full Text :
- https://doi.org/10.1016/j.jmb.2020.01.006