Homma Reiko, Mase Akiko, Toida Toshihiko, Kashiwagi Keiko, Igarashi Kazuei
Department of Clinical Biochemistry, Graduate School of Pharmaceutical Sciences, Chiba University, Chuo-ku, Japan.
Int J Biochem Cell Biol. 2005 Sep;37(9):1911-20. doi: 10.1016/j.biocel.2005.04.014.
The effects of polyamines on blood coagulation and fibrinolysis in the presence of glycosaminoglycans (GAGs) were examined because it is known that heparin (HP) interacts with polyamines, especially with spermine. Spermine was able to reverse the prolongation of coagulation time of rabbit plasma caused by HP. The effects of various GAGs on thrombin activity in the presence of anti-thrombin III (AT) were then tested using a synthetic substrate. Inhibition of thrombin activity by GAGs was in the order HP > heparan sulfate (HS) > dermatan sulfate (DS) >> chondroitin sulfate (CS) approximately hyaluronan (HA). When these GAGs were fully sulfonated, the inhibitory activity of HS, DS, CS and HA, but not HP, became stronger. The effects of GAGs on thrombin activity were reversed by polyamines, in particular spermine. The EC(50) value of spermine for reversal of HP inhibition was 30-50 microM, and the K(d) value of spermine for heparin was 41.1 microM. Analysis by surface plasmon resonance (SPR) indicated that the interaction between AT and HP was weakened by spermine through its binding to HP. The effect of HP on fibrinolysis was then examined. When Glu-plasminogen and tissue-type plasminogen activator (tPA) were used as enzyme source, HP strongly enhanced the plasmin activity and spermine reversed this effect. Analysis by SPR suggests that the structure of the active site of tPA may be changed through the ternary complex formation of tPA, HP and spermine. The results indicate that blood coagulation was enhanced and fibrinolysis was weakened by spermine in the presence of HP.
鉴于已知肝素（HP）与多胺相互作用，尤其是与精胺相互作用，因此研究了在存在糖胺聚糖（GAGs）的情况下多胺对血液凝固和纤维蛋白溶解的影响。精胺能够逆转由HP引起的兔血浆凝血时间延长。然后使用合成底物测试了各种GAGs在存在抗凝血酶III（AT）的情况下对凝血酶活性的影响。GAGs对凝血酶活性的抑制作用顺序为HP＞硫酸乙酰肝素（HS）＞硫酸皮肤素（DS）＞＞硫酸软骨素（CS）≈透明质酸（HA）。当这些GAGs完全磺化时，HS、DS、CS和HA的抑制活性增强，但HP的抑制活性不变。多胺，尤其是精胺，可逆转GAGs对凝血酶活性的影响。精胺逆转HP抑制作用的EC(50)值为30 - 50 μM，精胺与肝素的K(d)值为41.1 μM。表面等离子体共振（SPR）分析表明，精胺通过与HP结合削弱了AT与HP之间的相互作用。然后研究了HP对纤维蛋白溶解的影响。当使用Glu - 纤溶酶原和组织型纤溶酶原激活剂（tPA）作为酶源时，HP强烈增强纤溶酶活性，而精胺可逆转这种作用。SPR分析表明，tPA活性位点的结构可能通过tPA、HP和精胺形成的三元复合物而发生变化。结果表明，在存在HP的情况下，精胺增强血液凝固并减弱纤维蛋白溶解。
