The impact of the 67kDa laminin receptor on both cell-surface binding and anti-allergic action of tea catechins.
Here, we investigated the structure-activity relationship of major green tea catechins and their corresponding epimers on cell-surface binding and inhibitory effect on histamine release. Galloylated catechins; (-)-epigallocatechin-3-O-gallate (EGCG), (-)-gallocatechin-3-O-gallate (GCG), (-)-epicatechin-3-O-gallate (ECG), and (-)-catechin-3-O-gallate (CG) showed the cell-surface binding to the human basophilic KU812 cells by surface plasmon resonance analysis, but their non-galloylated forms did not. Binding activities of pyrogallol-type catechins (EGCG and GCG) were higher than those of catechol-type catechins (ECG and CG). These patterns were also observed in their inhibitory effects on histamine release. Previously, we have reported that biological activities of EGCG are mediated through the binding to the cell-surface 67kDa laminin receptor (67LR). Downregulation of 67LR expression caused a reduction of both activities of galloylated catechins. These results suggest that both the galloyl moiety and the B-ring hydroxylation pattern contribute to the exertion of biological activities of tea catechins and their 67LR-dependencies.
Fujimura
Yoshinori
Y
Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
Umeda
Daisuke
D
Yamada
Koji
K
Tachibana
Hirofumi
H
D018926:Anti-Allergic Agents / Q000494:pharmacology*; D001491:Basophils / Q000378:metabolism; D002392:Catechin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D045744:Cell Line, Tumor; D006031:Glycosylation; D006636:Histamine Release / Q000187:drug effects; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000473:pathology; D015394:Molecular Structure; D017474:Receptors, Laminin / Q000502:physiology*; D013329:Structure-Activity Relationship; D013662:Tea / Q000737:chemistry*
D018926:Anti-Allergic Agents; D017474:Receptors, Laminin; D013662:Tea; C417940:gallocatechin gallate; C417939:catechin gallate; D002392:Catechin; C062669:epicatechin gallate; C045651:epigallocatechin gallate