Domain versatility in plant AB-toxins: Evidence for a local, pH-dependent rearrangement in the 2γ lectin site of the mistletoe lectin by applying ligand derivatives and modelling

4 pags, 2 figs, 1 tab. -- Supplementary data associated with this article can be found, in the online version, at doi:10.1016/j.febslet.2008.05.035Mistletoe lectin is a potent biohazard. Lectin activity in the toxic dimer primarily originates from the 2γ-subdomain (Tyr-site) of the B-subunit. Crystallographic information on lectin-sugar complexes is available only at acidic pH, where lectin activity is low. Thus, we mapped ligand-binding properties including comparison to ricin's Tyr-site at neutral pH. Using these results and molecular dynamics simulations, a local conformational change was rendered likely. The obtained structural information is valuable for the design of potent inhibitors. © 2008 Federation of European Biochemical Societies.This work was supported by DGICYT (BQU2003-03550-C03-03 and BFU2006-10288/BMC), the research initiative LMUexcellent and an EC Marie Curie Research Training Network Grant (Contract No. MRTN-CT-2005-019561