The trhombin-like activities from the snake venoms of two subspecies of Bothrops atrox, moojeni (type I) and marajoensis (type II), were purified to homogeneity by affinity chromatography on a support consisting of the inhibitor, p-aminobenzamidine, linked to Sepharose 4B with a spacer of diaminodipropylaminosuccinate. At room temperature the enzyme was not bound to the affinity support but rat...

Gabonase, an enzyme which acts on fibrinogen and factor XI11 in uniquely thrombin-like ways, was purified to electrophoretic homogeneity from the venom of Bitis gabonica. On sodium dodecyl sulfate-polyacrylamide electrophoresis, the reduced protein behaved as a single chain with Mr = 30,600. The enzyme contains 20.6% carbohydrate, no free sulfhydryl groups and hence, from amino acid analysis, f...

Due to variability of venom components from the same species of snakes that inhabit different regions, particular properties of the venom of Crotalus durissus terrificus that inhabits the North-East of Argentina were studied. Gyroxin, a thrombin-like enzyme, was isolated from this venom by gel filtration and affinity chromatography, it was found to be homogeneous according to SDS-PAGE, with a m...

Like most metalloproteases, matrix metalloprotease 2 (MMP-2) is synthesized as a zymogen. MMP-2 propeptide plays a role in inhibition of catalytic activity through a cysteine-zinc ion pairing, disruption of which results in full enzyme activation. A variety of proteases have been shown to be involved in the activation of pro-MMP-2, including metalloproteases and serine proteases. In the previou...

abstract background autologus platelet gel is easy to prepare and is relatively low cost. the aim of this study was to prepare and evaluate in vitro efficacy of autologus platelet gel. materials and methods in this experimental study, platelet concentrate and platelet poor plasma were prepared with aphaeresis method. thrombin was prepared by mixing the plasma with calcium. thrombin activity lev...

A n extensive number of enzymes found in both plants and animals are activated by monovalent cations (1, 2). Pioneering work in the 1940s and 1950s revealed a critical K requirement for pyruvate kinase and the existence of Na-dependent activation of β-galactosidase (3, 4). Enzymes requiring K often can be activated by NH4 + and Rb but have more difficulties accommodating the larger Cs, and the ...

The serine protease thrombin is generated from its zymogen prothrombin at the end of the coagulation cascade. Thrombin functions as the effector enzyme of blood clotting by cleaving several procoagulant targets, but also plays a key role in attenuating the hemostatic response by activating protein C. These activities all depend on the engagement of exosites on thrombin, either through direct in...