Binding capacity of a barley beta-D-glucan to the beta-glucan recognition molecule dectin-1.
To clarify whether barley beta-glucans exhibit their biological effects via binding to dectin-1, a pivotal receptor for beta-1,3-glucan, the structure of barley beta-glucan E70-S (BBG-70) was unambiguously investigated by NMR spectroscopy and studied for its binding capacity and specificity to dectin-1 by ELISA. NMR spectroscopy confirmed that BBG-70 contains two different linkage glucans, namely, alpha-glucan and beta-glucan, which are not covalently attached to one another. Beta-glucan within BBG-70 is a linear mixed-linkage beta-glucan composed of 1,3- and 1,4-beta-D-glucopyranose residues but does not contain the continuous 1,3-linkage. Competitive ELISA revealed that highly purified barley beta-glucan E70-S (pBBG-70) inhibits the binding of soluble dectin-1 to sonifilan (SPG), a beta-1,3-glucan, although at a concentration higher than that of SPG and laminarin. It was found that barley beta-glucan can be recognized by dectin-1, implying that barley beta-glucan might, at least in part, exhibit its biological effects via the recognition by dectin-1 of the ligand sugar structure, which may be formed by 1,3-beta- and 1,4-beta-glucosyl linkage.
Tada
Rui
R
Laboratory for Immunopharmacology of Microbial Products, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Japan.
Adachi
Yoshiyuki
Y
Ishibashi
Ken-ichi
K
Tsubaki
Kazufumi
K
Ohno
Naohito
N
D000911:Antibodies, Monoclonal / Q000276:immunology; D001665:Binding Sites; D004797:Enzyme-Linked Immunosorbent Assay; D001467:Hordeum / Q000737:chemistry*; D037181:Lectins, C-Type; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D008968:Molecular Conformation; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000378:metabolism*; D011487:Protein Conformation; D013329:Structure-Activity Relationship; D047071:beta-Glucans / Q000737:chemistry / Q000378:metabolism*; D000099181:Dectin-1
D000911:Antibodies, Monoclonal; D037181:Lectins, C-Type; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D047071:beta-Glucans; D000099181:Dectin-1