Chemical and conformational study of the interactions involved in mycotoxin complexation with beta-D-glucans.
In a previous paper we reported that beta-D-glucans isolated from Saccharomyces cerevisiae could adsorb zearalenone, reduce its bioavailability in the digestive tract, and protect animals against its adverse effects. We have now investigated, in vitro, the kinetics of the interaction between other mycotoxins and beta-D-glucans from several sources at three pH values found along the digestive tract (3.0, 6.0, and 8.0). Acid and neutral conditions gave the highest affinity rates for aflatoxins B1 > deoxynivalenol > ochratoxin A and involved both the (1 --> 3)-beta-D-glucans and the (1 --> 6)-beta-D-glucans. Alkaline conditions, owing to their destructuring action on glucans, were favorable only for the adsorption of patulin. Using molecular mechanics, we found that hydroxyl, ketone, and lactone groups are involved in the formation of both hydrogen bonds and van der Waals interactions between aflatoxins B1, deoxynivalenol and patulin, and beta-D-glucans. Differences in the binding capacity of the mycotoxins are due to their specific physical and chemical characteristics.
Yiannikouris
Alexandros
A
Alltech-France, 14 Place Marie-Jeanne Bassot, 92300 Levallois-Perret, France. ayiannikouris@alltech.com
André
Gwénaëlle
G
Poughon
Laurent
L
François
Jean
J
Dussap
Claude-Gilles
CG
Jeminet
Georges
G
Bertin
Gérard
G
Jouany
Jean-Pierre
JP
D000327:Adsorption; D001665:Binding Sites; D002473:Cell Wall / Q000737:chemistry; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007700:Kinetics; D008958:Models, Molecular; D015394:Molecular Structure; D009183:Mycotoxins / Q000737:chemistry*; D011487:Protein Conformation; D012441:Saccharomyces cerevisiae / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013499:Surface Properties; D047071:beta-Glucans / Q000737:chemistry*
D009183:Mycotoxins; D047071:beta-Glucans; D012822:Silicon Dioxide