Green M D, Xiao L, Lal A A
Division of Parasitic Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
Mol Biochem Parasitol. 1996 Dec 20;83(2):183-8. doi: 10.1016/s0166-6851(96)02769-7.
Hemozoin, a heme byproduct of hemoglobin digestion by malaria parasites, is released into the blood stream of the host upon lysing of infected erythrocytes. Since heme-compounds are potent catalysts of lipid peroxidation, we evaluated the catalytic ability of Plasmodium falciparum-derived hemozoin to oxidize arachidonic acid to hydroxyeicosatetraenoic acids (HETEs). Hemozoin, beta-hematin, and hematin all catalyzed the formation of 15-, 12- and 5-HETE as major products. Although there were no significant differences in total amounts of HETEs generated by hemozoin relative to hematin or beta-hematin, there were significant differences in the proportions of certain isomers. 15-HETE was the predominant isomer generated by hemozoin catalysis while 5-HETE was the major product formed by hematin catalysis. Since HETEs are important vasoactive mediators, the non-enzymatic oxidation of arachidonic acid by hemozoin catalysis may contribute to some of the pathophysiology associated with severe and cerebral malaria.
疟色素是疟原虫消化血红蛋白产生的血红素副产物，在被感染红细胞裂解时释放到宿主的血流中。由于血红素化合物是脂质过氧化的强效催化剂，我们评估了恶性疟原虫来源的疟色素将花生四烯酸氧化为羟基二十碳四烯酸（HETEs）的催化能力。疟色素、β-血红素和血红素均催化形成主要产物15-、12-和5-HETE。尽管疟色素产生的HETEs总量与血红素或β-血红素相比没有显著差异，但某些异构体的比例存在显著差异。15-HETE是疟色素催化产生的主要异构体，而5-HETE是血红素催化形成的主要产物。由于HETEs是重要的血管活性介质，疟色素催化花生四烯酸的非酶氧化可能导致与严重疟疾和脑型疟疾相关的一些病理生理过程。
