Comparison of biological activities of human antithrombins with high-mannose or complex-type nonfucosylated N-linked oligosaccharides.
Comparison of biological activities of human antithrombins with high-mannose or complex-type nonfucosylated N-linked oligosaccharides.
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DOI：
10.1093/glycob/cww001
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发表时间：
2016-05
期刊：
影响因子：
4.3
通讯作者：
Satoh M
中科院分区：
文献类型：
--
作者：
Yamada T;Kanda Y;Takayama M;Hashimoto A;Sugihara T;Satoh-Kubota A;Suzuki-Takanami E;Yano K;Iida S;Satoh M
与抗凝血酶（AT）连接的N-连接寡糖的结构已被证明会影响其抗凝活性和药代动力学。人AT具有双触角复合型寡糖，其独特的特征是缺乏核心岩藻糖，这通过改变其肝素结合亲和力来影响其生物活性。在人血浆中，AT以含有四种寡糖的α-型和缺乏Asn 135处寡糖的β-型的混合物形式循环。然而，目前尚不清楚哺乳动物细胞产生的不成熟的高甘露糖型寡糖如何影响AT的生物学活性。在这里，我们成功地直接比较了高甘露糖和复杂类型之间的活性。有趣的是，虽然凝血酶抑制活性没有实质性差异，但高甘露糖型显示出更高的肝素结合亲和力。肝素可增加其抗凝活性，并与肝素结合亲和力相关，导致高甘露糖型的β-型显示出最强的抗凝活性。在药代动力学分析中，高甘露糖型的血浆半衰期比复合型短得多。对于高甘露糖型，发现β-型的血浆半衰期比α-型长;相反，对于复合型，α-型的半衰期比β-型长。本研究强调AT的生理活性不仅受到还原端核心岩藻糖的严格控制，而且还受到非还原端高甘露糖型结构的严格控制。具有未成熟的高甘露糖类型的β-形式一旦出现在血液中，似乎作为比通常在人血浆中发现的AT更有效的抗凝剂发挥作用。
The structure of the N-linked oligosaccharides attached to antithrombin (AT) has been shown to affect its anticoagulant activity and pharmacokinetics. Human AT has biantennary complex-type oligosaccharides with the unique feature of lacking a core fucose, which affects its biological activities by changing its heparin-binding affinity. In human plasma, AT circulates as a mixture of the α-form bearing four oligosaccharides and the β-form lacking an oligosaccharide at Asn135. However, it remains unclear how the immature high-mannose-type oligosaccharides produced by mammalian cells affect biological activities of AT. Here, we succeeded in directly comparing the activities between the high-mannose and complex types. Interestingly, although there were no substantial differences in thrombin inhibitory activity, the high-mannose type showed higher heparin-binding affinity. The anticoagulant activities were increased by heparin and correlated with the heparin-binding affinity, resulting in the strongest anticoagulant activity being displayed in the β-form with the high-mannose type. In pharmacokinetic profiling, the high-mannose type showed a much shorter plasma half-life than the complex type. The β-form was found to have a prolonged plasma half-life compared with the α-form for the high-mannose type; conversely, the α-form showed a longer half-life than the β-form for the complex-type. The present study highlights that AT physiological activities are strictly controlled not only by a core fucose at the reducing end but also by the high-mannose-type structures at the nonreducing end. The β-form with the immature high-mannose type appears to function as a more potent anticoagulant than the AT typically found in human plasma, once it emerges in the blood.