A REVIEW OF ELECTRON TRANSPORT MECHANISMS IN PARASITIC PROTOZOA
A REVIEW OF ELECTRON TRANSPORT MECHANISMS IN PARASITIC PROTOZOA
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DOI：
10.2307/3275663
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发表时间：
1963-01-01
影响因子：
1.3
通讯作者：
BAERNSTEIN, HD
中科院分区：
文献类型：
--
作者：
BAERNSTEIN, HD
本文综述了寄生原生动物电子传递的研究进展。疟原虫含有对氰化物、叠氮化物和一氧化碳敏感的氧化酶，表明存在细胞色素氧化酶。琥珀氧化酶和其他黄素蛋白的存在，通过氧摄取研究中靛酚和甲酚蓝的减少来判断。中间载体的存在是从萘醌对氧摄取的抑制推断的。毛滴虫具有有限的氧利用能力，这对氰化物不敏感，并且导致过氧化氢积累，除非过氧化氢酶也存在。一种黄素蛋白末端氧化酶被指出，但氧利用的重要性是未知的。一些菌株产生氢气，这可能与电子传递有关。生物体基本上是厌氧的，因此依赖于由吡啶和黄素蛋白介导的偶联反应，导致还原化合物的产生。锥虫显示了多种与氧相连的电子传递系统。多年来，氰化物被用来区分两种类型的氧化酶，一种是敏感的，一种是不敏感的。一般来说，所有锥虫的无脊椎动物或培养形式都具有氰化物敏感呼吸，而脊椎动物形式有两种类型：路易氏锥虫对氰化物敏感，布氏锥虫不敏感。所有组均显示传统的糖酵解途径，但只有敏感组显示活跃的柠檬酸循环反应和血红素蛋白谱。后者的性质知之甚少，似乎在某些方面与哺乳动物的类似因素不同。对氧的敏感途径与哺乳动物相似，但不敏感途径具有一些独特的特征。还原型烟酰胺腺嘌呤二核苷酸（NADH）1主要被磷酸二羟基丙酮再氧化生成甘油磷酸。它被脱氢酶氧化，脱氢酶可能是一种黄素蛋白，含有巯基和通过丙酮可溶因子与氧连接的金属。过氧化氢没有发现，因为它通常是在其他氰化物不敏感的氧化酶。
The literature related to electron transport in parasitic protozoa is reviewed. Plasmodia contain oxidases sensitive to cyanide, azide, and carbon monoxide, indicating the presence of cytochrome oxidase. Succinoxidase and other flavoproteins are present as judged by the reduction of indophenol and cresyl blue in oxygen uptake studies. The presence of intermediate carriers is inferred from the inhibition of oxygen uptake by naphthoquinones. Trichomonads have a limited capacity for oxygen utilization which is insensitive to cyanide and results in hydrogen peroxide accumulation except when catalase is also present. A flavoprotein terminal oxidase is indicated, but the importance of the oxygen utilization is not known. Some strains produce hydrogen gas which is probably linked to electron transport. The organisms are essentially anaerobic and therefore depend upon coupled reactions mediated by pyridino and flavoproteins resulting in the production of reduced compounds. Trypanosomes show a variety of electron transport systems linked to oxygen. Cyanide has for many years been used to distinguish two types a sensitive and an insensitive oxidase. In general the invertebrate or culture forms of all the trypanomsomes have cyanide sensitive respiration, whereas the vertebrate forms are of two types: the lewisi group are cyanide sensitive and the brucei group are insensitive. All groups show conventional glycolysis pathways, but only the sensitive group shows active citric cycle reactions and hemoprotein spectra. Little is known of the properties of the latter which seem to differ in some respects from analogous factors of mammals. The sensitive pathway to oxygen resembles that of mammals but the insensitive pathway has some unique characteristics. Reduced Nicotina-mide adenine dinucleotide (NADH)1 is reoxidized principally by di-hydroxyacetone phosphate to yield glycerophosphate. This is oxidized by a dehydrogenase which is probably a flavoprotein containing a sulfhydryl group and a metal linked to oxygen through an acetone soluble factor. Hydrogen peroxide is not found as it usually is in other cyanide insensitive oxidases.