Inhibition of platelet aggregation by grafting RGD and KGD sequences on the structural scaffold of small disulfide-rich proteins
Inhibition of platelet aggregation by grafting RGD and KGD sequences on the structural scaffold of small disulfide-rich proteins
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DOI：
10.1080/09537100500436663
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发表时间：
2006-05-01
期刊：
影响因子：
3.3
通讯作者：
Loesche, Wolfgang
中科院分区：
文献类型：
--
作者：
Reiss, Sandy;Sieber, Matthias;Loesche, Wolfgang
解整合素代表一组富含二硫键的肽，其大小从 41 个到超过 80 个残基不等，是多种整合素受体的拮抗剂。含有 RGD 或 KGD 序列的解整合素是血小板聚集的有效抑制剂，因为它们阻止纤维蛋白原与 α(IIb)β(3) 整合素的结合。与短线性肽相比，与 α(II)β(3) 的高亲和力结合归因于 RGD 或 KGD 序列在定义的三维结构内的定位。胱氨酸结微生物蛋白是另一个富含二硫键的小肽家族的成员，该肽仅由 28-40 个氨基酸残基组成。它们表现出多种生物活性，具体取决于固定在结构支架上的环区域的肽序列，该结构支架由三个形成结的二硫键稳定。在本研究中，我们将含有 7 个和 11 个氨基酸的肽序列的 RGD 和 KGD 分别移植到两种胱氨酸结微生物蛋白、胰蛋白酶抑制剂 EETI-II 和人刺豚鼠相关蛋白 AGRP 的黑皮质素受体结合结构域中，以及小的解整合素 obtustatin 中。与移植肽相比，工程蛋白在抑制纤维蛋白原结合、α(IIb)β(3) 激活和血小板聚集方面更有效。工程蛋白质之间观察到的差异表明结构支架和邻近接枝肽序列的氨基酸的重要性。
Disintegrins represent a group of disulfide-rich peptides ranging in size from 41 to over 80 residues and are antagonists of several integrin receptors. Disintegrins containing an RGD or KGD sequence are potent inhibitors of platelet aggregation as they block the binding of fibrinogen to alpha(IIb)beta(3) integrin. The high affinity binding to alpha(II)beta(3) in comparison to short linear peptides has been attributed to the localisation of the RGD or KGD sequence within a defined three-dimensional structure. Cystine knot microproteins are members of another family of small disulfide-rich peptides that consist of only 28-40 amino acid residues. They display numerous biological activities depending on the peptide sequence of loop regions that are fixed on a structural scaffold that is stabilised by three knot-forming disulfide bonds. In the present study we grafted RGD and KGD containing peptide sequences with seven and 11 amino acids, respectively, into two cystine knot microproteins, the trypsin inhibitor EETI-II and the melanocortin receptor binding domain of the human agouti-related protein AGRP, as well as into the small disintegrin obtustatin. The engineered proteins were much more potent to inhibit the fibrinogen binding, alpha(IIb)beta(3) activation and platelet aggregation when compared to the grafted peptides. Differences that were observed between the engineered proteins indicate the importance of the structural scaffold and the amino acids neighbouring the grafted peptide sequences.