Soybean trypsin inhibitor SBTI

EFEs are inhibited by a number of inhibitors, such as diisopropyl fluorophosphase (DFP) [24], soybean trypsin inhibitor (SBTI) [12,24], aprotinin [12,24], 1,6-hexamethylendiamine (HD) [49] and a2-macroglobulin (a2M) [50], etc. Nakajima et al. investigated some of the inhibitors when H-Z)-Phe-Pip-Arg-pNA is used as the substrate, as shown in Table (6). [24], DFP completely inhibits the activity of all the isozymes (pH 7.2) at room temperature. F-III-1 and F-II are strongly inhibited by SBTI and aprotinin, but F-I-0, -1-1 and -1-2 are partially inhibited. Nevertheless, Tosyl-phenylalanyl chloromethylketose (TPCK), tosyl-lysyl-chloromethylketose (TLCK), s-amino caproic acid (s-ACAk, elastatinal, EDTA and various metal ions, such as Fe2+, Cu2+ and Mnw cannot be detected to affect the activity under the conditions [24], On the basis of the specificity of substrates and inhibitors, EFE isomers are again exhibited the characteristics of alkaline serine-like proteases. 

As a further control, the Enzite-trypsin was incubated with soybean trypsin inhibitor (SBTI) prior to incubation with plasma. 

Figure 4. Renin concentration after 24 hr preincubation of plasma with trypsin (T) or trypsin and soybean trypsin inhibitor (SBTI). X—X plasma incubated without trypsin.

The trypsin inhibitor from Peltophorum dubium seeds (PDTI), as well as soybean trypsin inhibitor (SBTI), both belonging to the Kunitz family, have lectin-like prop>erties and trigger rat lymphoma cell apoptosis. It was shown that PDTI and SBTI induce human leukemia Jurkat cell death. Induction of apoptosis was confirmed by flow cytometry (Troncoso et al., 2009). 

The effect of EDTA on the rate of depolymerization and esterase activity was measured by the use of EDTA solutions instead of cholate buffer. The EDTA solution was neutralized to pH 7.0 and the final EDTA concentrations used were 0.025 M, 0.05 M, 0.075 M, 0.1 M, 0.15 M, 0.175 M and 0.2 M. EDTA controls without enzyme were also prepared. The effect of soybean trypsin inhibitor (SBTI) was also studied by using 0.25 mg/ml 0.5, 1, 1.5, 2.0 and 2.5 mg/ml of the inhibitor in the reaction mixture. 

Epsilon-Amino-n-Caproic Acid (EACA), C.P., homogeneous (Mann Research Labs.) in concentration of O.IM 0.4 ml per experiment was added. Plasminogen, human, purified (Mann Research Labs.) in concentration of 1 mg/ml VS (15 RPMI units/mg) 0.4 ml was added per experiment. Approximately 44-45 unit amounts (dissolved in VS) of Streptokinase (SK), 100,000 Christensen units/vial. 0.1 mg = 400 units (Lederle Laboratories) was used per experiment. Trypsin Inhibitor, Soybean (SBTI), chromatographic (component VI, salt free, lyoph.), 10,000 BAEE units of inhibition per mg (Mann Research Labs.), was... 

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