猪血纤维蛋白溶酶原的纯化及性质研究

 用偶联有L-赖氨酸的Sepharose 4B亲和柱对猪血纤维蛋白溶酶原进行分离纯化,所得酶原在酸性及SDS-聚丙烯酰胺凝胶电泳中显示单一蛋白质区带,在碱性条件下电泳及等电聚焦电泳表现出较明显的不均一性。还原及非还原SDS-聚丙烯酰胺凝胶电泳测得酶原分子量为88kD,经尿激酶激活后,进行还原SDS-凝胶电泳,出现两条新的蛋白质区带,分子量分别为63kD和26kD。酶原含中性糖1.35％,N-末端为异亮氨酸。尿激酶激活后产生的血纤维蛋白溶酶以对甲苯磺酰-L-精氨酸甲酯为底物,测得Km为4.2m mol/L,V_(max)为13.5 IU。6-氨基已酸对酶活性有双重影响。此外,还观察了胰蛋白酶对猪血纤维蛋白溶酶原的激活。

Purification and Characterization of Porcine Plasminogen

The porcine plasminogen (Pg) was purified by affinity chromatography on Lys-sepharose 4B column, and it is homogenous on acidic pH and SDS-PAGE, but it behaves obviously heterogeneous on basic PAGE and isoelective focusing elec-trophoreses. The molecular weight of porcine Pg determined by reduced and unreduced SDS-PAGE is 88 kD, After activation by urokinase (UK), porcine Pg yields two new bands, one is 63 kD, the other is 26 kD, The neutral saccharide content of porcine Pg is 1.35%. The porcine Plasmin activated by UK has a Km of 4.2 mmol/L and a Vmax of 13.5 IU in reaction with α-N-tosyl-L-arginine methyl ester (TAME) substrate. The activation of porcine Pg by trypsin was also noticed.