ELECTRON-TRANSPORT COMPONENTS OF THE PARASITIC PROTOZOAN GIARDIA-LAMBLIA
ELECTRON-TRANSPORT COMPONENTS OF THE PARASITIC PROTOZOAN GIARDIA-LAMBLIA
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DOI：
10.1016/0014-5793(93)81072-8
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发表时间：
1993-07-05
期刊：
影响因子：
3.5
通讯作者：
LLOYD, D
中科院分区：
文献类型：
--
作者：
ELLIS, JE;WILLIAMS, R;LLOYD, D
肠道寄生虫贾第鞭毛虫的能量代谢涉及铁硫蛋白丙酮酸：铁氧还蛋白氧化还原酶。细胞分级分离研究表明，这种酶与细胞膜相关。在膜和胞质部分中都发现了 NADH 和 NADPH 脱氢酶。 EPR 光谱研究表明，膜部分和细胞质部分中存在铁硫簇，在 6 x 10(6) g.min 下不可沉降。从细胞质中分离出酸性、可溶性蛋白质部分。它具有还原态的 EPR 谱，这是 2[4Fe-4S] 型铁氧还蛋白的特征，g 因子为 2.04、1.93 和 1.89，中点氧化还原电位估计为 -360 mV。该物种可能是一种铁氧还蛋白，就像梭状芽胞杆菌和脱硫弧菌属等厌氧细菌的铁氧还蛋白一样。还有溶组织内阿米巴。该蛋白质很容易且不可逆地氧化成[3Fe-4S]簇。
The energy metabolism of the intestinal parasite, Giardia lamblia, involves the iron-sulphur protein, pyruvate:ferredoxin oxidoreductase. Cell fractionation studies showed that this enzyme is associated with the membranes. NADH and NADPH dehydrogenases were found in both the membrane and cytosolic fractions. EPR spectroscopic studies showed the presence of iron-sulphur clusters in the membrane fraction and in the cytosolic fraction, non-sedimentable at 6 x 10(6) g.min. An acidic, soluble protein fraction was separated from the cytosol. It had an EPR spectrum in the reduced state, characteristic of the 2[4Fe-4S] type of ferredoxin, with g-factors at 2.04, 1.93 and 1.89, and the midpoint redox potential was estimated to be -360 mV. This species is probably a ferredoxin, like those of anaerobic bacteria such as Clostridium and Desulfovibrio spp. and also that of Entamoeba histolytica. The protein was readily and irreversibly oxidized to give [3Fe-4S] clusters.