Wada K, Onda M, Matsubara H
Department of Biology, Faculty of Science, Osaka University.
J Biochem. 1989 Apr;105(4):619-25. doi: 10.1093/oxfordjournals.jbchem.a122714.
Three ferredoxin isoproteins (R-Fd A, R-Fd B-1, and R-Fd B-2) were purified from white roots of radish (Raphanus sativus L. var. acantiformis cultivar Miyashige) and two isoproteins (L-Fd A and L-Fd B) from leaves. The amino acid sequences of three of them (L-Fd A, R-Fd B-1, and R-Fd B-2) were determined and compared with one another and with those of other higher plant ferredoxins so far studied. L-Fd A and R-Fd B-1 had heterogeneities at four and two amino acid sites, respectively. Two isoprotein (R-Fd B-1 and R-Fd B-2) were deduced to be expressed only in root tissue on the basis of sequence studies and amino acid compositions of all isoferredoxins isolated from the radish plant. The root ferredoxins sequenced in this study were similar to each other, but quite different from other higher plant ferredoxins, all of which were isolated from leaf tissue. The coupling activities of these ferredoxin isoproteins were measured in the NADP+-photoreduction system of radish chloroplasts and glutamate synthase [EC 1.4.7.1] systems isolated from radish leaf and root tissues. No distinctive physiological characteristics were observed among these isoferredoxins.
从萝卜（Raphanus sativus L. var. acantiformis cultivar Miyashige）的白色根中纯化出三种铁氧还蛋白同工蛋白（R-Fd A、R-Fd B-1和R-Fd B-2），从叶片中纯化出两种同工蛋白（L-Fd A和L-Fd B）。测定了其中三种（L-Fd A、R-Fd B-1和R-Fd B-2）的氨基酸序列，并相互比较，还与迄今研究的其他高等植物铁氧还蛋白的氨基酸序列进行了比较。L-Fd A和R-Fd B-1分别在四个和两个氨基酸位点存在异质性。根据对从萝卜植株中分离出的所有异铁氧还蛋白的序列研究和氨基酸组成，推断两种同工蛋白（R-Fd B-1和R-Fd B-2）仅在根组织中表达。本研究中测序的根铁氧还蛋白彼此相似，但与所有从叶组织中分离出的其他高等植物铁氧还蛋白有很大不同。在萝卜叶绿体的NADP⁺-光还原系统以及从萝卜叶和根组织中分离出的谷氨酸合酶[EC 1.4.7.1]系统中，测定了这些铁氧还蛋白同工蛋白的偶联活性。在这些异铁氧还蛋白中未观察到明显的生理特征。
