Single amino acid residues in the E- and P-selectin epidermal growth factor domains can determine carbohydrate binding specificity
Single amino acid residues in the E- and P-selectin epidermal growth factor domains can determine carbohydrate binding specificity
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DOI：
10.1074/jbc.271.27.16160
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发表时间：
1996-07-05
影响因子：
4.8
通讯作者：
Beck, PJ
中科院分区：
文献类型：
--
作者：
Revelle, BM;Scott, D;Beck, PJ
E-选择素和P-选择素是两种密切相关的血管细胞黏附蛋白，每个选择素都有一个氨基末端的C型凝集素结构域，被认为具有与唾液酸化的Lewis(X)抗原(SLE(X)或CD15s)(Neu5Acα2-3GalBeta1-4(Fuc Alpha 1-3)GlcNAc)结合的碳水化合物结合部位，除了SLE(X)碳水化合物外，P-选择素还结合硫酸化的蛋白多糖、3-硫酸基半乳糖神经酰胺(硫脂化)和肝素，E-和P-选择素都有一个与凝集素结构域相邻的类EGF结构域和COOH-末端，Ne报道，P-或E-选择素EGF结构域上单一氨基酸残基的突变替代可以显著改变选择素与SLE(X)、肝素或硫脂的结合，E-和P-选择素EGF结构域残基Ser(128)用精氨酸取代导致E-和P-选择素蛋白失去对α1-3连接岩藻糖的需求，从而能够与唾液酸内酰胺结合。此外，我们已经确定，EGF结构域残基124和128的保守取代可以改变E-选择素结合，使得它能够附着于肝素或硫脂，并可以减少P-选择素与这些配体的粘连，被取代的EGF结构域氨基酸残基与凝集素结构域内初级碳水化合物结合位置之间的距离以及它们的相对位置由E-选择素凝集素和EGF结构域的三维晶体结构决定(Graves，B.J.，Crowther，R.L.，Chandran，C.，Rumberger，J.B.，Li，S.，Huang，D.-S.，Presby，D.H.，Familletti，P.C.，Wolitzky，B.A.，and Burns，D.K.(1994)Nature 367,532-538)表明这两个结构域之间几乎没有直接接触，然而，我们报告了突变的结合特征，表明选择素寡糖结合可能受这两个结构域的调控，野生型E-和P-选择素/SLE(X)结合作用可能与先前假设的显著不同。
E-selectin and P-selectin are two closely related vascular cell adhesion proteins, Each selectin has an amino-terminal C-type lectin domain that is thought to possess the carbohydrate binding site that binds the sialylated Lewis(x) antigen (sLe(x) or CD15s) (Neu5Ac alpha 2-3Gal beta 1-4(Fuc alpha 1-3)GlcNAc), In addition to the sLe(x) carbohydrate, P-selectin binds sulfated proteoglycan, 3-sulfated galactosyl ceramide (sulfatide), and heparin, Both E- and P-selectin have an EGF-like (EGF) domain that is immediately adjacent to and COOH-terminal to the lectin domain, Ne report that mutagenic substitution of single amino acid residues in either the P- or E-selectin EGF domain can dramatically alter selectin binding to sLe(x), heparin, or sulfatide, Substitution of E- and P-selectin EGF domain residue Ser(128) with an arginine results in E- and P selectin proteins that have lost the requirement for alpha 1-3-linked fucose and are thus able to bind to sialyllactosamine. A similar phenotype is reported for an E-selectin mutation within the lectin domain, Additionally, we have determined that conservative substitution of EGF domain residues 124 and 128 can alter E-selectin binding such that it is able to adhere to heparin or sulfatide and can reduce P-selectin adherence to these ligands, The distance between the substituted EGF domain amino acid residues and the primary carbohydrate binding site within the lectin domain and their relative positioning as determined by the three-dimensional crystal structure of the E-selectin lectin and EGF domains (Graves, B. J., Crowther, R. L., Chandran, C., Rumberger, J. B., Li, S., Huang, D.-S., Presby, D. H., Familletti, P. C., Wolitzky, B. A., and Burns, D. K. (1994) Nature 367, 532-538) suggest that there is little direct contact between the two domains, However, we report mutant binding characteristics which indicate that selectin oligosaccharide binding may be modulated by both domains and that wild-type E- and P-selectin/sLe(x) binding interactions may be significantly different from those previously hypothesized.