ABSTRACT
Objective To express and purify recombinant protease with thrombolysis activity of Perinereis aibuhitensis Grube and study on its characterization.Methods pMAL-PPA was in- troduced into E.coli DH5?to construct engineering bacteria and overexpression of the prote- ase of fused with maltose binding protein(MBP-PPA)was achieved with IPTG induction. The fusion protein was purified by affinity chromatography on amylose-resin column fol- lowed by chromatography on a DEAE-sepharose FF column.PPA cut with Factor Xa was assayed using casein plates supplied with plasminogen.Results Engineering bacteria express- ing maltose binding protein-thrombolytic protease of P.aibuhitensis were constructed and overexpression of MBP-PPA was achieved with IPTG induction.A recombinant fusion pro- tein of 51kD was purified,and PPA cut down from the fusion protein had a plasminogen-acti- rating activity.The protease showed a good thermal stability with an optimal pH of 8.0. This enzyme was also relatively stable in a pH range of 6.0～9.0 and still active after stored in organic solvents for 20d.Conclusion PPA was verified as a plasminogen activator,and might be a new thrombolytic medicine in the future.
ABSTRACT
Objective To investigate the anticoagulant activities of phlorotannins STP-1 and STP-2 from Sargassum thunbeergii Kuntze.Methods Coagulation time(CT)and bleeding time(BT)of mice were determined by in-vivo experiment to test the effect of phlorotannins by capillary method and cutting tail method respectively.Furthermore,activated partial thromboplastin time(APTT),prothrombin time(PT)and thrombin time(TT)were measured to evaluate the in-vitro anticoagulant activity of phlorotannins on New Zealand rabbits.Results Phlorotannins STP-1 had a significant effect on the prolongation of CT,BT,APTT,PT and TT,especially at the dosage of 1.0 mg/mL.Conclusion Phlorotannins STP-1 has both in-vivo and in-vitro anticoagulant activity.
ABSTRACT
Perilla frutescens callus were induced from leave explants on MS medium suplemented with NAA and 2,4-D. The Rosmarinic acid (RosA) content of dried callus was 0.85%. The RosA was extracted from the callus with 80% alcohol and purified through extraction with ethyl acetate and a Sephadex LH-20 column chromatography. The parity of the final product was 95% as analyzed by HPLC RosA could inhibit the growths of Escherichia colt, Staphylococcus aueris and Rhizotonia with MICs of 300, 400, 800?g/mL, respectively.