Figure 3.

Different forms of Stx2a bound to different receptors/serum factors are recognized by ELISA or by the luminometric cell-free translation system (LCFTS) as described in Materials and Methods. The diagram shows different toxin forms based on the bound molecule (HuSAP, TLR4 or Gb3Cer), the soluble (bound to serum factors) or particulated (microvesicle (MV)-associated) condition and the status (cleaved or uncleaved) of the A chain. Each specific toxin form is either detected (green) or not detected (red) by the specific assay (ELISA, LCFTS), as experimentally demonstrated (filled rectangles) or as inferred according to its features (red rectangles with step lines).