[低分子量合成抑制剂对α-凝血酶酶活性的抑制作用]

[Inhibition of enzymatic activity of alpha-thrombin by low molecular weight synthetic inhibitor].

作者信息

Kireeva E G, Strukova S M, Dugina T N, Sokolov V B, Aksinenko A Iu

出版信息

Biokhimiia. 1992 Jan;57(1):21-6.

Abstract

The effect of the organophosphoric inhibitor, SA-152, on the fibrinogen-coagulating and TAME-esterase activity of bovine alpha-thrombin was studied. The irreversible inhibition constants (k11 = 1.1 x 10(4) M-1.min-1,Ki = 0.7 x 10(-4) M, k2 = 0.8 min-1 towards the coagulating activity and kII = 0.7 x 10(4) M-1.min-1, Ki = 0.3 x 10(-4) M, k2 = 0.2 min-1 towards the esterase activity) were determined. The SA-152 inactivated alpha-thrombin was dialyzed and incubated with 0.5 M and 2.5 M NaCl and 10 mM TAME. There was no reconstitution of activity of the SA-152 modified alpha-thrombin after dialysis and treatment with high concentrations of NaCl and TAME. Heparin interactions with the anion-binding site of the high molecular weight recognition center in the alpha-thrombin molecule did not significantly influence the values of the kinetic constants for the enzyme inhibition by SA-152. This finding is consistent with the hypothesis on the irreversible binding of SA-152 in the active center of the enzyme.

摘要

研究了有机磷酸抑制剂SA - 152对牛α - 凝血酶的纤维蛋白原凝固活性和TAME - 酯酶活性的影响。测定了不可逆抑制常数（对凝固活性而言，k11 = 1.1×10⁴ M⁻¹·min⁻¹，Ki = 0.7×10⁻⁴ M，k2 = 0.8 min⁻¹；对酯酶活性而言，kII = 0.7×10⁴ M⁻¹·min⁻¹，Ki = 0.3×10⁻⁴ M，k2 = 0.2 min⁻¹）。将被SA - 152灭活的α - 凝血酶进行透析，并与0.5 M和2.5 M的NaCl以及10 mM的TAME一起孵育。在透析以及用高浓度的NaCl和TAME处理后，SA - 152修饰的α - 凝血酶的活性没有恢复。肝素与α - 凝血酶分子中高分子量识别中心的阴离子结合位点之间的相互作用，对SA - 152抑制该酶的动力学常数的值没有显著影响。这一发现与SA - 152在酶活性中心不可逆结合的假说一致。