Purification and biochemical characterization of a novel secretory dipeptidyl peptidase IV from porcine serum.

Purification of DPP-IV enzyme from porcine serum, is presented in this study for the first time. The high molecular weight DPP-IV from porcine serum was fractioned using Sephadex G-75 gel filtration followed by DEAE Sephadex anion exchange and Sephadex G-100 gel filtration chromatography columns with a final yield of 11.25%. The SDS-PAGE of the purified sample showed a single band of molecular mass nearing 160 kDa. Distinct single band was observed after PAS staining confirmed it to be a glycoprotein. The purified enzyme showed an optimum pH and temperature of 8 and 37 °C, respectively. The enzyme effectively cleaved fluorogenic substrate Gly-Pro-AMC with Km and Vmax of 4.578 µM and 90.84 nmoles/min, respectively. Purified DPP-IV activity was inhibited by Diprotin A with an IC50 value of 8.473 µM. Among the three plant extracts used to study DPP-IV inhibition, the aqueous hot extract of Terminalia chebula showed the highest inhibition of 87.19%, followed by the aqueous cold extract of Momordica carantia, ( 31.6%) and Azadirachta indica (34.16%) at the concentration of 25 µg.

Procoagulant serine glycoprotease from Cucumis sativus L.: action on human fibrinogen and fibrin clot.

Upon examination of the fruit extract of Cucumis sativus L. for its pharmacological benefits, it was previously observed that it has potential proteolytic, fibrinogenolytic and procoagulant activities. These properties can be attributed to the presence of the protease. In this regard, the present study comprised of purification and characterization of protease. Purification of the enzyme involved ammonium sulfate precipitation followed by gel filtration and ion exchange chromatography. The purified cucumis protease (CPro) exhibits homogeneity as attested by SDS-PAGE and RP-HPLC with a retention time of 14.246 min with molecular mass ~75.3 kDa. CPro was identified as a glycoprotein and serine protease. Azocasein is the preferred substrate for CPro as it showed low Km value of 0.3809 mg/ml. Purified CPro exhibits optimum activity at 37 °C and pH 8. CPro shows its involvement in hemostasis-the very first step in wound healing. CPro degrades the subunits of human fibrinogen in the order Aα > Bß > Î³. It also hydrolyzes the subunits of the partially cross-linked fibrin clot in the order α-polymer > Î³-γ dimer > ß-chain. CPro reduced the clotting time of citrated plasma, prothrombin time and activated partial thromboplastin time of plasma. CPro is neither hemorrhagic nor edema-inducing, thus considered to be a non-toxic protease. This work provides evidence for the use of cucumber extract in wound healing and authenticates its use in cosmetics.