Pettigrew G W, Leaver J L, Meyer T E, Ryle A P
Biochem J. 1975 May;147(2):291-302. doi: 10.1042/bj1470291.
A basic cytochrome was isolated from the phytomastigophorean protozoan Euglena gracilis and a similar protein from the zoomastigophorean protozoan Crithidia oncopelti. In both cases chromatography on CM-cellulose in first the reduced and then the oxidized form proved to be an efficient means of purification. The two cytochromes can be classed in the cytochrome c family but they have certain atypical features. The alpha peak of the absorption spectrum is shifted towards the red and is asymmetrical. The pyridine ferrohaemochrome has an alpha-peak maximum intermediate between that of c-type cytochromes and proteins containing protohaem IX. The test for free vinyl groups was positive. The amino acid sequences of the two cytochromes were determined. Attention is drawn in the text to those parts of the evidence that are less satisfactory. Both sequences are homologous with the family of cytochrome c, but are unusual in having only one cysteine residue so that the haem is attached through only one thioether bond. Detailed evidence for the amino acid dequences of the two proteins has been deposited as Supplementary Publication SUP 50042 (70 pages) at the British Library (Lending Division) (formerly the National Lending Library for Science and Technology), Boston Spa, Wetherby, Yorks. LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1975) 145, 5.
从植物性鞭毛虫原生动物纤细裸藻中分离出一种碱性细胞色素，并从动物性鞭毛虫原生动物罗氏锥虫中分离出一种类似的蛋白质。在这两种情况下，先将还原型然后将氧化型在CM-纤维素上进行色谱分析都被证明是一种有效的纯化方法。这两种细胞色素可归类于细胞色素c家族，但它们具有某些非典型特征。吸收光谱的α峰向红色移动且不对称。吡啶亚铁血红素的α峰最大值介于c型细胞色素和含有原血红素IX的蛋白质的α峰最大值之间。游离乙烯基测试呈阳性。测定了这两种细胞色素的氨基酸序列。文中提请注意证据中不太令人满意的部分。两种序列都与细胞色素c家族同源，但不同寻常的是它们都只有一个半胱氨酸残基，因此血红素仅通过一个硫醚键连接。这两种蛋白质氨基酸序列的详细证据已作为补充出版物SUP 50042（70页）存放在英国图书馆（借阅部）（原国家科学技术借阅图书馆），地址为英国约克郡韦瑟比市波士顿温泉村LS23 7BQ，可按《生物化学杂志》（1975年）第145卷第5期所示条件从该处获取复印件。
