Srivastava P, Sharma G D, Kamboj K K, Rastogi A K, Pandey V C
Division of Biochemistry, Central Drug Research Institute, Lucknow, India.
Mol Cell Biochem. 1997 Jun;171(1-2):65-8. doi: 10.1023/a:1006830113376.
Promastigotes of Leishmania donovani (Dd-8 strain) showed presence of important key enzymes of heme synthesizing (delta-aminolevulinic acid synthase and ferrochelatase) and degrading (heme oxygenase and biliverdin reductase) systems, classical leishmanicidal drugs viz allopurinol, amphotericin B, pentamidine and CDRI compound 93/202 inhibited the heme oxygenase activity of the parasite, whereas, delta-aminolevulinic acid synthase activity practically remained unaffected. The Km, Vmax and pH values of heme oxygenase of promastigotes were found to be 1666 microM hemin, 625 nmol of bilirubin formed h-1 mg protein-1 and 7.5 respectively. The findings suggest the presence and importance of heme metabolism in the de novo synthesis of different hemoproteins of the Leishmania parasite as well as the detoxification and its defence against biological insults.
杜氏利什曼原虫（Dd - 8株）前鞭毛体显示存在血红素合成（δ-氨基乙酰丙酸合成酶和亚铁螯合酶）和降解（血红素加氧酶和胆绿素还原酶）系统的重要关键酶，经典的抗利什曼原虫药物，即别嘌呤醇、两性霉素B、喷他脒和CDRI化合物93/20抑制了寄生虫的血红素加氧酶活性，而δ-氨基乙酰丙酸合成酶活性实际上未受影响。前鞭毛体血红素加氧酶的Km、Vmax和pH值分别为1666微摩尔血红素、每小时每毫克蛋白质形成625纳摩尔胆红素和7.5。这些发现表明血红素代谢在利什曼原虫不同血红蛋白的从头合成以及解毒及其对生物损伤的防御中的存在和重要性。
