Mechanism of enhancement by fucoidan and CNBr-fibrinogen digest of the activation of glu-plasminogen by tissue plasminogen activator.
Mechanism of enhancement by fucoidan and CNBr-fibrinogen digest of the activation of glu-plasminogen by tissue plasminogen activator.
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岩藻依聚糖和 CNBr-纤维蛋白原消化增强组织纤溶酶原激活剂对谷氨酰胺酶原激活的机制。
DOI：
10.1007/bf03190080
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发表时间：
2000
影响因子：
1.9
通讯作者：
Doctor,VM
中科院分区：
文献类型：
--
作者：
Muneer,E;Bell,J;Doctor,VM
用岩藻多糖-琼脂糖亲和层析法研究了岩藻多糖与人谷氨酸型纤溶酶原（Glu-Plg）、猪胰弹性蛋白酶酶解纤溶酶原组分和双链组织型纤溶酶原激活剂（t-PA）的相互作用。结果显示岩藻聚糖-琼脂糖凝胶与Glu-Plg或PlgK 1 − 3之间具有高度亲和力，但与PlgK 4或mini-Plg之间没有亲和力。岩藻聚糖-琼脂糖凝胶也显示出对t-PA的高亲和力，这在很大程度上被0.002 M 6-氨基己酸（6-AH）逆转。在0.002 M 6-AH存在下，岩藻依聚糖和CNBr-纤维蛋白原消化物（CNBr-Fbg）对t-PA体外激活Glu-Plg的作用增强最大。亲和层析和增强研究的结果表明，模板机制，因为增加浓度的任何一个两个辅因子逆转增强。使用双倒数图的酶动力学研究表明，添加岩藻依聚糖-6-AH使Kcat增加7倍而不影响Kcat，并且添加CNBr-Fbg使Km降低5倍而不显著影响Kcat，而添加两种辅因子使Km降低16倍而不显著影响Kcat。褐藻糖胶-6-AH或CNBr-Fbg对t-PA激活Glu-Plg的增强作用可被纤溶酶原激活物抑制剂1（派-1）逆转。岩藻多糖-琼脂糖亲和层析结果表明，岩藻多糖与派-1的结合可能是岩藻多糖-6-AH逆转PAI-1增强的原因。
The interactions of fucoidan with human glutamic type plasminogen (Glu-Plg), porcine pancreatic elastase digested plasminogen fractions and two chain tissue plasminogen activator t-PA) were investigated using fucoidan-Sepharose affinity chromatography. The results showed a high degree of affinity between fucoidan-Sepharose and Glu-Plg or PlgK1−3but not with PlgK4or mini-Plg. Fucoidan-Sepharose also showed a high affinity for t-PA, which was largely reversed by 0.002 M 6-aminohexanoic acid (6-AH). The addition of fucoidan and CNBr-fibrinogen digest (CNBr-Fbg) gave the highest enhancement of thein vitroactivation of Glu-Plg by t-PA in the presence of 0.002 M 6-AH. The results of affinity chromatography and enhancement studies suggested a template mechanism, since increasing the concentrations of any one of the two cofactors reversed the enhancement. Enzyme kinetic studies, using double reciprocal plots, showed that the addition of fucoidan-6-AH increased Kcatby 7-fold without affecting Kmand addition of CNBr-Fbg lowered Kmby 5-fold without significantly affecting Kcatwhile addition of the two cofactors lowered Kmby 16-fold without significantly affecting Kcat. The enhancement by fucoidan-6-AH or by CNBr-Fbg of thein vitroactivation of Glu-Plg by t-PA was reversed by plasminogen activator inhibitor 1 (PAI-1). Fucoidan-Sepharose affinity chromatography revealed that the binding of PAI-1 with fucoidan may be responsible for the reversal of the enhancement by fucoidan-6-AH.