Summaria L, Boreisha I, Barlow G H, Robbins K C
Department of Surgery, Evanston Hospital, Illinois.
Thromb Haemost. 1987 Aug 4;58(2):772-7.
A ternary equimolar human plasmin B-chain-streptokinase-plasminogen complex was isolated from a mixture of the plasmin B-chain-streptokinase complex and human plasminogen at 0 degrees C and 37 degrees C. A ternary complex which was shown to be species specific, was identified and characterized by ultracentrifugal, acrylamide gel electrophoretic, and agarose double diffusion analyses. When mixed at a 1:1 molar ratio at 0 degrees C, 39.9% of the preparation existed as a plasmin B-chain-streptokinase-plasminogen complex; when mixed at 37 degrees C, 86.4% existed as a complex, which was identified by electrophoretic analyses to be a plasmin B-chain-streptokinase-plasmin complex. Sedimentation velocity analyses gave s degrees 20,w values of 3.79 for the plasmin B-chain-streptokinase complex, 4.10 for Lys-plasmin, and 6.23 for the plasmin B-chain-streptokinase-plasmin complex. Sedimentation equilibrium analyses gave molecular weights of 73,900 for the plasmin B-chain-streptokinase complex, 82,900 for Lys-plasmin, and 153,100 for the plasmin B-chain-streptokinase-plasmin complex. The diisopropylphosphorofluoridate (DFP)-inhibited and the p-nitrophenyl-p-guanidino-benzoate (NPGB)-inhibited plasmin B-chain-streptokinase complexes both retained their ability to form a ternary complex with human plasminogen, but this complex did not convert to a plasmin B-chain-streptokinase-plasmin complex. Thus, the active site serine residue is essential for the activator activity of the plasmin B-chain-streptokinase complex, but it is not necessary for the binding of the plasmin B-chain-streptokinase complex to plasminogen to form a ternary complex.
在0℃和37℃条件下，从纤溶酶B链 - 链激酶复合物与人纤溶酶原的混合物中分离出一种三元等摩尔人纤溶酶B链 - 链激酶 - 纤溶酶原复合物。通过超速离心、丙烯酰胺凝胶电泳和琼脂糖双向扩散分析鉴定并表征了一种具有物种特异性的三元复合物。当在0℃以1:1摩尔比混合时，制剂中39.9%以纤溶酶B链 - 链激酶 - 纤溶酶原复合物形式存在；当在37℃混合时，86.4%以复合物形式存在，经电泳分析鉴定为纤溶酶B链 - 链激酶 - 纤溶酶复合物。沉降速度分析得出，纤溶酶B链 - 链激酶复合物的s20,w值为3.79，赖氨酰 - 纤溶酶为4.10，纤溶酶B链 - 链激酶 - 纤溶酶复合物为6.23。沉降平衡分析得出，纤溶酶B链 - 链激酶复合物的分子量为73,900，赖氨酰 - 纤溶酶为82,900，纤溶酶B链 - 链激酶 - 纤溶酶复合物为153,100。二异丙基氟磷酸酯（DFP）抑制的和对硝基苯基 - p - 胍基 - 苯甲酸酯（NPGB）抑制的纤溶酶B链 - 链激酶复合物都保留了与人类纤溶酶原形成三元复合物的能力，但这种复合物不会转化为纤溶酶B链 - 链激酶 - 纤溶酶复合物。因此，活性位点丝氨酸残基对于纤溶酶B链 - 链激酶复合物的激活剂活性至关重要，但对于纤溶酶B链 - 链激酶复合物与纤溶酶原结合形成三元复合物并非必需。
