Ip S M, Rowell P, Aitken A, Stewart W D
Eur J Biochem. 1984 Jun 15;141(3):497-504. doi: 10.1111/j.1432-1033.1984.tb08220.x.
Thioredoxin has been purified to homogeneity from the cyanobacterium Anabaena cylindrica. The protein consists of a single polypeptide chain with a relative molecular mass of about 11 680 which has two cysteine residues (residues 31 and 34) in the sequence-Cys-Gly-Pro-Cys- and an isoelectric point at pH 4.55. The N-terminal amino acid sequence of 39 residues shows distinct homologies with the sequences of Escherichia coli and Corynebacterium nephridii thioredoxins. Anti-(A. cylindrica thioredoxin) antiserum was used to quantify the thioredoxin which constituted about 0.22% of the soluble protein in cell-free extracts of N2-fixing, NO3- -grown or NH4+-grown A. cylindrica. Activation of fructose-1,6-bisphosphatase of A. cylindrica, activation of glutamine synthetase and NADP+-dependent malate dehydrogenase of the green alga Scenedesmus obliquus but not of A. cylindrica, and deactivation of glucose-6-P dehydrogenase of the cyanobacterium Anabaena variabilis were all achieved using the same thioredoxin species. No other thioredoxin species were detected in extracts of A. cylindrica when examined for the activation of these enzymes.
已从圆柱鱼腥藻中纯化出均一的硫氧还蛋白。该蛋白质由一条相对分子质量约为11680的单多肽链组成，其序列-Cys-Gly-Pro-Cys-中有两个半胱氨酸残基（第31和34位残基），等电点为pH 4.55。39个残基的N端氨基酸序列与大肠杆菌和肾状棒杆菌硫氧还蛋白的序列有明显的同源性。抗（圆柱鱼腥藻硫氧还蛋白）抗血清用于定量硫氧还蛋白，其在固氮、以硝酸盐或铵盐生长的圆柱鱼腥藻的无细胞提取物中占可溶性蛋白质的约0.22%。使用相同的硫氧还蛋白物种实现了圆柱鱼腥藻果糖-1,6-二磷酸酶的激活、斜生栅藻谷氨酰胺合成酶和NADP⁺依赖性苹果酸脱氢酶（但圆柱鱼腥藻的未实现）的激活以及多变鱼腥藻葡萄糖-6-磷酸脱氢酶的失活。在检测这些酶的激活时，在圆柱鱼腥藻提取物中未检测到其他硫氧还蛋白物种。
