The binding of lactoferrin to glycosaminoglycans on enterocyte-like HT29-18-C1 cells is mediated through basic residues located in the N-terminus
The binding of lactoferrin to glycosaminoglycans on enterocyte-like HT29-18-C1 cells is mediated through basic residues located in the N-terminus
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DOI：
10.1016/s0304-4165(01)00222-7
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发表时间：
2001-12-19
影响因子：
3
通讯作者：
Spik, G
中科院分区：
文献类型：
--
作者：
El Yazidi-Belkoura, I;Legrand, D;Spik, G
尽管从各种哺乳动物的乳汁中分离出的乳铁蛋白 (Lfs) 表现出密切的结构关系，但它们与细胞的结合具有物种特异性。为了确定人肠细胞识别人乳铁蛋白 (hLf)、牛乳铁蛋白 (bLf) 和鼠乳铁蛋白 (mLf) 的特异性，我们分析了这三种蛋白与源自人癌细胞系 HT29 的亚克隆的结合。我们观察到 hLf 和 bLf 与两种类型的结合位点相互作用（K-d：63 +/- 22 nM；0.7 +/- 0.2 muM），而 mLf 仅被结合位点数量较少的最低亲和力结合位点识别。使用N端删除的人类Lf变体，我们发现序列G(1)RRRR(5)主要负责与HT29细胞的相互作用。 HT29细胞表面的乳铁蛋白结合位点被进一步鉴定为硫酸乙酰肝素和硫酸软骨素糖胺聚糖。我们得出的结论是，bLf 中序列 A(1)PRK(4) 和 mLf 中序列 K(1)ATT(4) 的存在提供了关于为什么 bLf 与细胞膜相关糖胺聚糖的相互作用与 hLf 相似以及为什么这些乳铁蛋白种类的结合不同于鼠 Lf 的结合的见解。 (C) 2001 Elsevier Science B.V. 保留所有权利。
Although lactoferrins (Lfs) isolated from milk of various mammals exhibit a close structural relationship, they show species-specific binding to cells. To define the specificity of recognition of human (hLf), bovine (bLf) and murine (mLf) lactoferrin by human intestinal cells, we analysed the binding of the three proteins to a subclone derived from human carcinoma cell line HT29. We observed that hLf and bLf interact with two types of binding sites (K-d: 63 +/- 22 nM; 0.7 +/- 0.2 muM) while mLf was recognized only by the lowest affinity binding sites with a lower number of binding sites. Using N-terminal deleted human Lf variants, we found that the sequence G(1)RRRR(5) is mainly responsible for the interactions with HT29 cells. Lactoferrin-binding sites on the surface of HT29 cells were further identified as heparan sulphate and chondroitin sulphate glycosaminoglycans. We conclude that the presence of the sequence A(1)PRK(4) in bLf and K(1)ATT(4) in mLf provides an insight into why the interaction of bLf with cell membrane-associated glycosaminoglycans is similar to that of hLf and why binding of these lactoferrin species differs from that of murine Lf. (C) 2001 Elsevier Science B.V. All rights reserved.