Related Experiment Video
Updated: Jul 5, 2026

Monitoring the Assembly of a Secreted Bacterial Virulence Factor Using Site-specific Crosslinking
Published on: December 17, 2013
VAR2CSA domains expressed in Escherichia coli induce cross-reactive antibodies to native protein
Andrew V Oleinikov1, Susan E Francis, Jeffrey R Dorfman
1Seattle Biomedical Research Institute, University of Washington, Seattle, USA.
Abstract:
The variant surface antigen VAR2CSA is a pregnancy malaria vaccine candidate, but its size and polymorphism are obstacles to development. We expressed 3D7-type VAR2CSA domains in Escherichia coli as insoluble His-tagged proteins (Duffy binding-like [DBL] domains DBL1, DBL3, DBL4, and DBL5) that were denatured and refolded or as soluble glutathione S-transferase-tagged protein (DBL6). Anti-DBL5 antiserum cross-reacted with surface proteins of chondroitin sulfate A (CSA)-binding laboratory strains (3D7-CSA and FCR3-CSA) and a clinical pregnancy malaria isolate, whereas anti-DBL6 antiserum reacted only to 3D7 surface protein. This is the first report that E. coli-expressed VAR2CSA domains induce antibody to native VAR2CSA.
Related Concept Videos
Cross-reactivity
Bacterial Gastroenteritis
Stringent Response in E. coli
Enzyme-Linked Immunosorbent Assay
There are many different types of ELISAs, but they all involve an antibody molecule whose constant region binds an enzyme, leaving the variable region free to bind its specific antigen. Enzyme-substrate reaction allows the antigen to be visualized or quantified.

