Lee Alvin, White Natalie, van der Walle Christopher F
Pharmaceutical Sciences, Institute for Biomedical Sciences, University of Strathclyde, 27 Taylor Street, Glasgow, G4 0NR, UK.
FEBS Lett. 2003 Dec 18;555(3):638-42. doi: 10.1016/s0014-5793(03)01348-6.
A preliminary structural analysis of Vibrio cholerae zonula occludens toxin (ZOT) was made by equilibrium denaturation and circular dichroism. ZOT is a structurally unstable protein in aqueous solution (DeltaG((H2O)) 3.82 kcal/mol), the putative intra- and extracellular domains unfold co-operatively, with complete denaturation via observed conformational intermediates. Refolding of denatured ZOT is not dependent on disulphide bridge formation. Partial refolding of a maltose binding protein-ZOT fusion did not prevent its specific binding to the ZOT receptor on Caco-2 cells. Immuno-gold labelling showed that the ZOT receptor localises to the intercellular contacts between cells in a confluent monolayer.
