Extraction, purification, and biochemical characterization of serine protease from leaves of Abrus precatorius

Abstract

A protease from fresh leaves of Abrus precatorius was purified using two classical chromatography techniques: ion-exchange (DEAE-Sepharose) and Gel filtration (Sephadex G-75). The purified protease showed a molecular weight of ∼ 28 kDa on sodium dodecyl sulfate polyacrylamide gel electrophoresis. The optimum pH and temperature for the purified protease was 8 and 40°C, respectively. The purified protease was stable throughout a wide temperature range from 10 to 80°C and pH from 2 to 12. Protease activity was inhibited in the presence of Co, Ni, Hg, and Zn while its activity has increased in the presence of Ca and Mg. The protease was highly specific to casein when compared to its specificity for gelatin, bovine serum albumin, hemoglobin, and defatted flour of Ricinodendron heudelotii. Its V and K determined using casein as a substrate were 94.34 U/mL and 349.07 µg/mL respectively. Inhibition studies showed that this purified protease was inhibited by both phenylmethane sulfonyl fluoride and aprotinin which are recognized as competitive inhibitors of serine proteases.

Icariin Exerts Estrogen-Like Actions on Proliferation of Osteoblasts in Vitro via Membrane Estrogen Receptors-Mediated Non-nuclear Effects

“…Ultraviolet/visible absorption spectra indicated the formation of BSA-ICA complexes. It has been shown that protease can be purified from fresh chicken wing leaves by DEAE-Sepharose and Sephadex G-75 chromatography (23). Another study described and tested a method for isolating ring cells using an immunosorbent based on Sephadex G-75.…”