Strukova S M, Semenova O A, Kireeva E G, Sereĭskaia A A, Romanova V P
Biokhimiia. 1982 Apr;47(4):528-33.
The kinetic parameters of hydrolysis of methyl esters of N alpha-arylsulfonyl-arginine and N-arylsulfonyl-valyl-arginine by alpha- and beta/gamma-thrombins were calculated. It was found that the polarity and volume of arylsulfonyl substitute are essential for hydrolysis of N alpha-arylsulfonyl-arginine esters and only slightly affect the hydrolysis of N-arylsulfonyl-valyl-arginine esters. Incorporation of the valine residue into the substrate molecule sharply increases the catalytic constant, thus suggesting an important role of secondary sites of the enzyme binding to the substrate. A comparison of alpha- and beta/gamma-thrombins did not reveal any substantial differences in their ability to hydrolyze synthetic esters; consequently the structure of the region around the enzyme active center which is involved in interactions with the substrates under study, is not responsible for alpha-thrombin specificity for fibrinogen.
计算了α-凝血酶和β/γ-凝血酶对Nα-芳基磺酰基-精氨酸甲酯和N-芳基磺酰基-缬氨酰-精氨酸甲酯的水解动力学参数。发现芳基磺酰基取代基的极性和体积对于Nα-芳基磺酰基-精氨酸酯的水解至关重要，而对N-芳基磺酰基-缬氨酰-精氨酸酯的水解影响较小。缬氨酸残基掺入底物分子中会显著增加催化常数，这表明酶与底物结合的二级位点具有重要作用。对α-凝血酶和β/γ-凝血酶的比较未发现它们水解合成酯的能力有任何实质性差异；因此，酶活性中心周围参与与所研究底物相互作用的区域结构，并非α-凝血酶对纤维蛋白原特异性负责的原因。
