Bactericidal Activity of Recombinant Human Platelet Phospholipase A_2 in Vitro Against Staphylococcus Aureus and Its Impact Factors / 中国药房

ABSTRACT

OBJECTIVE:To evaluate the bactericidal activity of recombinant human platelet phospholipase A2(RHP-PLA2)in vitro against S.aureus and the effects of different impact factors on the bactericidal activity of it.METHODS:The bactericidal activity of RHP-PLA2 was tested by agar plating method,and the impact factors(pH,Ca2+,Mg2+,negatively charged heparin)were determined.RESULTS:The minimum bactericidal concentration(MBC)of RHP-PLA2 killing 99% S.aureus was 0.08 ng?L-1.The bactericidal rates of PLA2 at MBC were 44.4%,99.8% and 99.5% respectively in the pH of 5.0,7.4 and 9.0.1 ～5 mmol Ca2+ was suitable for the bactericidal activity of the RHP-PLA2.The bactericidal activity of RHP-PLA2 can be completely inhibited by 5.12 mmol?L-1 EGTA,10 mmol?L-1 MgCl2 or 0.30?10-4 IU?L-1 heparin.CONCLUSIONS:The bactericidal activity of RHP-PLA2 is affected by pH and Ca2+ concentration in media.The cationic property of PLA2 is the key factor influencing its bactericidal activity.