蒿甲醚、血红素及Fe^3＋对重组日本血吸虫乳酸脱氢酶(rSjLDH)作用的初步研究

Effect of artmether,hemin and Fe^(3+) on recombinant lactate dehydrogenase from Schistosoma japonicum(rSj LDH)

目的检测蒿甲醚、血红素及Fe3+对rSjLDH的抑制作用,探讨蒿甲醚抗血吸虫幼虫可能的作用机制。方法在获得rSjLDH及建立标准酶活性测定体系的基础上,在标准酶活性测定体系中加入不同浓度的蒿甲醚、血红素及Fe3+,以药物相应的溶剂作为对照,测定药物对酶活性的影响。结果与相应对照组相比较,0.1 mmol/L的蒿甲醚对rSjLDH催化丙酮酸还原为乳酸及乳酸氧化为丙酮酸的反应无抑制作用(P>0.05);血红素对rSjLDH有极强的抑制作用,在0.015mmol/L时,rSjLDH催化乳酸氧化反应的活性被完全抑制(P<0.01),在浓度为0.02 mmol/L时,rSjLDH催化丙酮酸还原为乳酸的反应被抑制93.48%(P<0.01);0.1mmol/L蒿甲醚配伍0.004mmol/L血红素未发现对rSjLDH的抑制;Fe3+对rSjLDH有较强抑制作用,0.5mmol/L时rSjLDH催化正、逆反应的活性被完全抑制(P<0.01)。结论蒿甲醚对rSjLDH无抑制作用;血红素对rSjLDH有极强的抑制作用;蒿甲醚与血红素未发现有配伍作用;Fe3+对rSjLDH有较强的抑制作用。提示蒿甲醚不直接作用于SjLDH,血红素是SjLDH的强抑制剂,其在蒿甲醚作用机制中的作用需进一步研究。

To detect the effect of artemether, heroin and Fe^3＋ on rSjLDH, enzyme activity was assayed in the standard reaction system by adding different concentration of veagents（artemether, hemin and Fe^3＋ ）, and same solvents of the each reagent were used as control. It was found that in the concentration of 0. 1mmol/L artemther, no inhibition of enzyme activity on reduction and oxidation reaction was observed, compared with the control （P〉0.05）. At the concentration of 0.02mmol/L hemin, enzymatic activity was inhibited at 93.48 % for pyruvate reduction reaction and 100.00 % for lactate oxidation reaction, in comparison with that of the control （P〈0.01）. No inhibition was observed when 0. 1mmol/L artemether plus 0. 004mmol/L hemin. Was at the concentration of 0.5mmol/L Fe^3＋ , both pyruvate reduction and lactate oxidation reaction were inhibited completely （P〈0.01）. The results implied that SjLDH was not the direct molecular target of artemether, the role of hemin in mechanism of artemether should be further studied.