Cell-surface prion protein interacts with glycosaminoglycans
Cell-surface prion protein interacts with glycosaminoglycans
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DOI：
10.1042/bj20020773
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发表时间：
2002-11-15
影响因子：
4.1
通讯作者：
Sy, MS
中科院分区：
文献类型：
--
作者：
Pan, T;Wong, BS;Sy, MS
我们用ELISA法和流式细胞术研究了PrP蛋白与糖胺多聚糖(GAG)的结合。我们发现重组人PrP(RPrP)能与硫酸软骨素A、硫酸软骨素B、透明质酸和肝素结合。RPrP通过N-末端与GAG结合，N-末端是已知的结合二价阳离子的区域。此外，在CuCl2+的存在下，rPrP与GaG的结合增强，而在Call和Mn2+的存在下则不增强。RPrP与肝素结合最强，这种结合可被某些肝素类似物抑制，包括肝素二糖和含硫酸盐的单糖，但不能被乙酰化肝素抑制。来自人脑的全长正常细胞蛋白(PRP(C))，但不是N端截短的PrPC物种，以类似的Cu2+/Zn2+增强的方式结合GAG。我们发现GAG与rPrP N端23-35位氨基酸残基对应的合成肽特异结合。我们进一步证明，野生型PrPC和由转基因细胞产生的八肽重复缺失突变体PrP都能与肝素结合在细胞表面，而PrP N端缺失突变体和非转染体对照未能与肝素结合。肝素与细胞表面野生型PrPC的结合导致细胞表面PrPC水平降低。这些结果为PrPC是GAG的表面受体提供了强有力的证据。
We used ELISA and flow cytometry to study the binding of prion protein PrP to glycosaminoglycans (GAGs). We found that recombinant human PrP (rPrP) binds GAGs including chondroitin sulphate A, chondroitin sulphate B, hyaluronic acid, and heparin. rPrP binding to GAGs occurs via the N-terminus, a region known to bind divalent cations. Additionally, rPrP binding to GAGs is enhanced in the presence of Cull and Zn2+, but not Call and Mn2+. rPrP binds heparin strongest, and the binding is inhibited by certain heparin analogues, including heparin disaccharide and sulphate-containing monosaccharides, but not by acetylated heparin. Full-length normal cellular prion protein (Prp(C)), but not N-terminally truncated PrPC species, from human brain bind GAGs in a similar Cu2+/Zn2+-enhanced fashion. We found that GAGs specifically bind to a synthetic peptide corresponding to amino acid residues 23-35 in the N-terminus of rPrP. We further demonstrated that while both wild-type PrPC and an octapeptide-repeat-deleted mutant PrP produced by transfected cells bound heparin at the cell surface, the PrP N-terminal deletion mutant and non-transfectant control failed to bind heparin. Binding of heparin to wild-type PrPC on the cell surface results in a reduction of the level of cell-surface PrPC. These results provide strong evidence that PrPC is a surface receptor for GAGs.