67kDa层粘连蛋白受体对茶儿茶素的细胞表面结合及抗过敏作用的影响。
The impact of the 67kDa laminin receptor on both cell-surface binding and anti-allergic action of tea catechins.
作者信息
Fujimura Yoshinori, Umeda Daisuke, Yamada Koji, Tachibana Hirofumi
机构信息
Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
出版信息
Arch Biochem Biophys. 2008 Aug 15;476(2):133-8. doi: 10.1016/j.abb.2008.03.002. Epub 2008 Mar 7.
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.
在此,我们研究了主要绿茶儿茶素及其相应差向异构体在细胞表面结合以及对组胺释放的抑制作用方面的构效关系。没食子酰化儿茶素,即(-)-表没食子儿茶素-3-O-没食子酸酯(EGCG)、(-)-没食子儿茶素-3-O-没食子酸酯(GCG)、(-)-表儿茶素-3-O-没食子酸酯(ECG)和(-)-儿茶素-3-O-没食子酸酯(CG),通过表面等离子体共振分析显示与人嗜碱性KU812细胞存在细胞表面结合,但它们的非没食子酰化形式则没有。连苯三酚型儿茶素(EGCG和GCG)的结合活性高于儿茶酚型儿茶素(ECG和CG)。在它们对组胺释放的抑制作用中也观察到了这些模式。此前,我们曾报道EGCG的生物学活性是通过与细胞表面67kDa层粘连蛋白受体(67LR)结合来介导的。67LR表达的下调导致没食子酰化儿茶素的两种活性均降低。这些结果表明,没食子酰基部分和B环羟基化模式都有助于茶儿茶素生物学活性的发挥及其对67LR的依赖性。