Peptide agonist of the thrombopoietin receptor as potent as the natural cytokine
Peptide agonist of the thrombopoietin receptor as potent as the natural cytokine
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DOI：
10.1126/science.276.5319.1696
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发表时间：
1997-06-13
期刊：
影响因子：
56.9
通讯作者：
Dower, WJ
中科院分区：
文献类型：
--
作者：
Cwirla, SE;Balasubramanian, P;Dower, WJ
从重组肽库中鉴定出两个与人血小板生成素受体结合并与天然配体血小板生成素（TPO）竞争结合的小肽家族，它们的序列在TPO的一级序列中未发现，在亲和选择性条件下筛选这些家族之一的变体文库产生了14个氨基酸的肽具有高亲和力的（Ile-Glu-Gly-Pro-Thr-Leu-Arg-Gln-Trp-Leu-Ala-Ala-Arg-Ala）（解离常数约为2纳摩尔），其以400纳摩尔的中位有效浓度（EC 50）刺激TPO响应性Ba/F3细胞系的增殖，该肽通过羧基末端连接至赖氨酸分支的二聚化产生具有100皮摩尔的EC 50的化合物，其在基于细胞的测定中与332个氨基酸的天然细胞因子等效，肽二聚体也刺激了体外增殖和成熟的巨核细胞从人骨髓细胞，并促进血小板计数的增加时，给药到正常小鼠。
Two families of small peptides that bind to the human thrombopoietin receptor and compete with the binding of the natural ligand thrombopoietin (TPO) were identified from recombinant peptide libraries, The sequences of these peptides were not found in the primary sequence of TPO, Screening libraries of variants of one of these families under affinity-selective conditions yielded a 14-amino acid peptide (Ile-Glu-Gly-Pro-Thr-Leu-Arg-Gln-Trp-Leu-Ala-Ala-Arg-Ala) with high affinity (dissociation constant approximate to 2 nanomolar) that stimulates the proliferation of a TPO-responsive Ba/F3 cell line with a median effective concentration (EC50) of 400 nanomolar, Dimerization of this peptide by a carboxyl-terminal linkage to a lysine branch produced a compound with an EC50 of 100 picomolar, which was equipotent to the 332-amino acid natural cytokine in cell-based assays, The peptide dimer also stimulated the in vitro proliferation and maturation of megakaryocytes from human bone marrow cells and promoted an increase in platelet count when administered to normal mice.