Biochemical, Kinetic and Biological Properties of Group V Phospholipase A2 from Dromedary

Abstract

Secretory group V phospholipase A2 (PLA2-V) is known to be involved in inflammatory processes in cellular studies, nevertheless, the biochemical and the enzymatic characteristics of this important enzyme have been unclear yet. We reported, as a first step towards understanding the biochemical properties, catalytic characteristics, antimicrobial and cytotoxic effects of this PLA2, the production of PLA2-V from dromedary. The obtained DrPLA2-V has an absolute requirement for Ca2+ and NaTDC for enzymatic activity with an optimum pH of 9 and temperature of 45 °C with phosphatidylethanolamine as a substrate. Kinetic parameters showed that Kcat/Kmapp is 2.6 ± 0.02 mM−1 s−1. The enzyme was found to display potent Gram-positive bactericidal activity (with IC50 values of about 5 µg/mL) and antifungal activity (with IC50 values of about 25 µg/mL)in vitro. However, the purified enzyme did not display a cytotoxic effect against cancer cells.

Effective Soybean Oil Degumming by Immobilized Phospholipases A2 from Walterinnesia aegyptia Venom

“…Additionally, a strict dependence on Ca 2+ was observed for all tested enzymes, which were completely inactive without added Ca 2+ and the presence of EDTA or EGTA as chelator agents (Figure C,D). These findings were consistent with those of earlier investigations on PLA 2 from various sources, therefore emphasizing the crucial role of Ca 2+ in stabilizing the enzyme–substrate interactions during the catalysis mechanism. ,, …”

“…These findings were consistent with those of earlier investigations on PLA 2 from various sources, therefore emphasizing the crucial role of Ca 2+ in stabilizing the enzyme–substrate interactions during the catalysis mechanism. 3 , 37 , 40 …”