Probing interactions between β-glucan and bile salts at atomic detail by ¹H-¹³C NMR assays.
Polysaccharides are prospective hosts for the delivery and sequestration of bioactive guest molecules. Polysaccharides of dietary fiber, specifically cereal (1 → 3)(1 → 4)-β-glucans, play a role in lowering the blood plasma cholesterol level in humans. Direct host-guest interactions between β-glucans and conjugated bile salts are among the possible molecular mechanisms explaining the hypocholesterolemic effects of β-glucans. The present study shows that (1)H-(13)C NMR assays on a time scale of minutes detect minute signal changes in both bile salts and β-glucans, thus indicating dynamic interactions between bile salts and β-glucans. Experiments are consistent with stronger interactions at pH 5.3 than at pH 6.5 in this in vitro assay. The changes in bile salt and β-glucan signals suggest a stabilization of bile salt micelles and concomitant conformational changes in β-glucans.
Faculty of Science, Department of Food Science, University of Copenhagen , Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark.
Mette Skau
MS
Mikkelsen
Sofia Bolvig
SB
Cornali
Morten G
MG
Jensen
Mathias
M
Nilsson
Sophie R
SR
Beeren
Sebastian
S
Meier
D001647:Bile Acids and Salts / Q000737:chemistry*; D001786:Blood Glucose / Q000378:metabolism; D066241:Carbon-13 Magnetic Resonance Spectroscopy / Q000379:methods*; D002784:Cholesterol / Q000097:blood; D004043:Dietary Fiber / Q000494:pharmacology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D047071:beta-Glucans / Q000737:chemistry* / Q000494:pharmacology
D001647:Bile Acids and Salts; D001786:Blood Glucose; D004043:Dietary Fiber; D047071:beta-Glucans; D002784:Cholesterol
HSQC; bile salt; glucan; heteronuclear NMR