Tryptophan as a molecular shovel in the glycosyl transfer activity of Trypanosoma cruzi trans-sialidase

Molecular dynamics investigations into active site plasticity of Trypanosoma cruzi trans-sialidase, a protein Implicated in Chagas disease, suggest that movement of the Trp312 loop plays an important role in the enzyme's sialic acid transfer mechanism. The observed Trp312 flexibility equates to a molecular shovel action, which leads to the expulsion of the donor aglycone leaving group from the catalytic site. These computational simulations provide detailed structural insights into sialyl transfer by the trans-sialidase and may aid the design of inhibitors effective against this neglected tropical disease. © 2010 by the Biophysical Society.