Characterization of the interaction between platelet factor 4 and homogeneous synthetic low molecular weight heparins
Characterization of the interaction between platelet factor 4 and homogeneous synthetic low molecular weight heparins
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DOI：
10.1111/jth.14657
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发表时间：
2019-10-20
影响因子：
10.4
通讯作者：
Greinacher, Andreas
中科院分区：
文献类型：
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作者：
Thi-Huong Nguyen;Xu, Yongmei;Greinacher, Andreas
背景 肝素通常由动物组织产生。现在可以合成肝素。这提供了克服肝素短缺、优化生物效应并减少药物不良反应的能力。肝素与血小板因子 4 (PF4) 相互作用，可诱导免疫反应，导致血小板减少症。这种副作用称为肝素诱导的血小板减少症（HIT）。我们表征了 PF4 和 HIT 抗体与 6、8、10 和 12 聚体大小的寡糖以及超硫酸化 12 聚体 (S12-mer) 的相互作用。方法我们利用等温量热法、圆二色光谱、单分子力光谱 (SMFS)、酶免疫吸附测定 (EIA) 和血小板聚集试验等多种方法来表征合成肝素类似物与 PF4 和抗 PF4/肝素抗体的相互作用。结果合成的类肝素化合物比相应长度的动物源性肝素表现出更强的 PF4 结合特性。与 PF4 络合后，6 聚体和 S12 聚体肝素表现出低得多的焓，引起 PF4 的构象变化较少，并且与 8 聚体、10 聚体和 12 聚体肝素相比，相互作用力更弱。抗 PF4/肝素抗体与 PF4 和肝素 = 10 聚体之间形成的复合物的结合更弱。在 12 聚体上添加一个硫酸基团产生了 S12 聚体，其与 PF4 的结合特性显示出显着变化。结论 我们提供了一个模板，用于表征新开发的基于肝素的抗凝药物与蛋白质（尤其是 PF4）的相互作用以及由此产生的潜在抗原性。
Background Heparins are usually produced from animal tissues. It is now possible to synthesize heparins. This provides the abilities to overcome shortages of heparin, to optimize biological effects, and to reduce adverse drug effects. Heparins interact with platelet factor 4 (PF4), which can induce an immune response causing thrombocytopenia. This side effect is called heparin-induced thrombocytopenia (HIT). We characterized the interaction of PF4 and HIT antibodies with oligosaccharides of 6-, 8-, 10-, and 12-mer size and a hypersulfated 12-mer (S12-mer). Methods We utilized multiple methodologies including isothermal calorimetry, circular dichroism spectroscopy, single molecule force spectroscopy (SMFS), enzyme immunosorbent assay (EIA), and platelet aggregation test to characterize the interaction of synthetic heparin analogs with PF4 and anti-PF4/heparin antibodies. Results The synthetic heparin-like compounds display stronger binding characteristics to PF4 than animal-derived heparins of corresponding lengths. Upon complexation with PF4, 6-mer and S12-mer heparins showed much lower enthalpy, induced less conformational changes in PF4, and interacted with weaker forces than 8-, 10-, and 12-mer heparins. Anti-PF4/heparin antibodies bind more weakly to complexes formed between PF4 and heparins = 10-mer. Addition of one sulfate group to the 12-mer resulted in a S12-mer, which showed substantial changes in its binding characteristics to PF4. Conclusions We provide a template for characterizing interactions of newly developed heparin-based anticoagulant drugs with proteins, especially PF4 and the resulting potential antigenicity.