来自嗜盐菌的一种新型植物型铁氧化还原蛋白。

A new plant-type ferredoxin from halobacteria.

作者信息

Kerscher L, Oesterhelt D, Cammack R, Hall D O

出版信息

Eur J Biochem. 1976 Dec;71(1):101-7. doi: 10.1111/j.1432-1033.1976.tb11094.x.

DOI:10.1111/j.1432-1033.1976.tb11094.x

Abstract

A stable, 2Fe-type ferredoxin has been prepared from Halobacterium halobium and purified by chromatography. A similar ferredoxin was also found in three other Halobacteria. The ferredoxin is present in large amounts-about 1 percent of the total soluble protein. From amino acid composition a molecular weight of 14800 +/- 200 was calculated. The ferredoxin was found to contain two atoms each of iron and sulphide. The midpoint redox potential of the protein is about -345 mV. The electron paramagnetic resonance spectrum of the reduced form shows much similarity to plant and algal ferredoxins with gx = 1.90, gy = 1.97 and gz = 2.07. The same similarity is observed in the optical absorption, optical rotatory dispersion and circular dichroism spectra. However it does not seem to mediate electron transport in the NADP-photoreduction system of chloroplasts. Extracts of the bacterial cells catalyze the reduction of the ferredoxin by NADH.

摘要

一种稳定的2Fe型铁氧化还原蛋白已从嗜盐嗜盐菌中制备出来，并通过色谱法进行了纯化。在其他三种嗜盐菌中也发现了类似的铁氧化还原蛋白。这种铁氧化还原蛋白大量存在，约占总可溶性蛋白的1%。根据氨基酸组成计算出分子量为14800±200。发现该铁氧化还原蛋白每个分子含有两个铁原子和两个硫原子。该蛋白的中点氧化还原电位约为-345 mV。还原形式的电子顺磁共振谱与植物和藻类铁氧化还原蛋白非常相似，gx = 1.90，gy = 1.97，gz = 2.07。在光吸收、旋光色散和圆二色光谱中也观察到了同样的相似性。然而，它似乎并不介导叶绿体NADP光还原系统中的电子传递。细菌细胞提取物催化NADH对铁氧化还原蛋白的还原反应。