Multivalent fucosides with nanomolar affinity for the Aspergillus fumigatus lectin FleA prevent spore adhesion to pneumocytes.

Multivalent fucosides with nanomolar affinity for the Aspergillus fumigatus lectin FleA prevent spore adhesion to pneumocytes. Chemistry. 2018 Oct 02;: Authors: Gouin SG, Lehot V, Brissonnet Y, Dussouy C, Brument S, Cabanettes A, Gillon E, Deniaud D, Varrot A, Le Pape P Abstract FleA (or AFL), a fucose lectin, was recently identified in the opportunistic mold Aspergillus fumigatus that causes fatal lung infections in immunocompromised patients. We designed di-, hexa- and octavalent fucosides with various spacer arm lengths to block the hexameric FleA via chelation. Microcalorimetry measurements showed that the ethylene glycol (EG) spacer arm length has a strong influence on the binding affinity of the divalent fucosides. The relationship between the EG length and chelate binding efficiency to FleA was explored according to polymer theory. Hexa- and octavalent compounds based on cyclodextrin and octameric silsesquioxane scaffolds were nanomolar FleA inhibitors, surpassing their monovalent fucose analogue by more than three orders of magnitude. Importantly, some of the fucosides were highly efficient in preventing fungal spore adhesion to bronchoepithelial cells with half maximal inhibitory concentration values in the micromolar range. We propose that the synergistic anti-adhesive effect observed can be ascribed to chelate binding to FleA and to the formation of conidium aggregates as observed by optical microscopy. These fucosides are...
Source: Chemistry - Category: Chemistry Authors: Tags: Chemistry Source Type: research