Interaction of heparin with two synthetic peptides that neutralize the anticoagulant activity of heparin.
Interaction of heparin with two synthetic peptides that neutralize the anticoagulant activity of heparin.
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DOI：
10.1021/bi061346a
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发表时间：
2006-12
期刊：
影响因子：
2.9
通讯作者：
Jing Wang;D. Rabenstein
中科院分区：
文献类型：
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作者：
Jing Wang;D. Rabenstein
合成了两个肝素/硫酸肝素相互作用蛋白的肝素结合区类似物(Ac-SRGKAKVKAKVKDQTK-NH2)和同一肽的全d氨基酸版本(分别为L-HIPAP和d-HIPAP)，并测定了它们作为中和肝素抗凝血剂的效果。通过用Coatest肝素法恢复丝氨酸蛋白酶Xa的活性，发现这两个类似的多肽对肝素的抗凝血活性有同样的中和作用。L-HIPAP和d-HIPAP同样有效的发现表明，D-氨基酸肽有望成为中和肝素抗凝血活性的蛋白水解性稳定的治疗剂。用核磁共振氢谱、恒温滴定量热法和肝素亲和层析法研究了L-羟丙基AP和d-羟丙基AP与肝素的相互作用。研究发现，这两种多肽与肝素的相互作用相同。用反离子缩合理论分析了肝素-多肽结合常数与Na+浓度的关系，结果表明，平均每个结合的多肽分子中有2.35个Na+离子从肝素上移位，每个肝素的六糖段结合一个多肽分子。分析还表明，离子和非离子相互作用都对结合常数有贡献，离子作用的贡献随着Na+浓度的增加而减小。
Two synthetic analogues of the heparin-binding domain of heparin/heparan sulfate-interacting protein (Ac-SRGKAKVKAKVKDQTK-NH2) and the all-d-amino acid version of the same peptide (l-HIPAP and d-HIPAP, respectively) were synthesized, and their efficacy as agents for neutralization of the anticoagulant activity of heparin was assayed. The two analogue peptides were found to be equally effective for neutralization of the anticoagulant activity of heparin, as measured by restoration of the activity of serine protease factor Xa by the Coatest heparin method. The finding that l-HIPAP and d-HIPAP are equally effective suggests that d-amino acid peptides show promise as proteolytically stable therapeutic agents for neutralization of the anticoagulant activity of heparin. The interaction of l-HIPAP and d-HIPAP with heparin was characterized by 1H NMR, isothermal titration calorimetry (ITC), and heparin affinity chromatography. The two peptides were found to interact identically with heparin. Analysis of the dependence of heparin-peptide binding constants on Na+ concentration by counterion condensation theory indicates that, on average, 2.35 Na+ ions are displaced from heparin per peptide molecule bound and one peptide molecule binds per hexasaccharide segment of heparin. The analysis also indicates that both ionic and nonionic interactions contribute to the binding constant, with the ionic contribution decreasing as the Na+ concentration increases.