Silvestrini M C, Tegoni M, Célerier J, Desbois A, Gervais M
Dipartimento di Scienze Biochimiche, Università di Roma La Sapienza, Italy.
Biochem J. 1993 Oct 15;295 ( Pt 2)(Pt 2):501-8. doi: 10.1042/bj2950501.
The flavin and haem domains of Hansenula anomala flavocytochrome b2 have been independently expressed in Escherichia coli. The flavin domain activity, studied only in the total cellular extract, owing to its instability, has characteristics very similar to those of the flavin domain obtained by proteolysis. The haem domain (r-core) has been purified to homogeneity and characterized in detail from spectroscopic and functional points of view. Spectral differences with respect to the domain produced by proteolysis (p-core) were found using resonance Raman and c.d. spectroscopy and have been interpreted in terms of changes in haem-protein interactions. However, this structural difference is functionally silent, since the r-core is able to reduce cytochrome c with the same efficiency as the proteolytic domain.
异常汉逊酵母黄素细胞色素b2的黄素结构域和血红素结构域已在大肠杆菌中独立表达。由于黄素结构域不稳定,仅在全细胞提取物中研究了其活性,其特性与通过蛋白水解获得的黄素结构域非常相似。血红素结构域(r-核心)已纯化至同质,并从光谱学和功能角度进行了详细表征。使用共振拉曼光谱和圆二色光谱发现了与蛋白水解产生的结构域(p-核心)相比的光谱差异,并根据血红素-蛋白质相互作用的变化进行了解释。然而,这种结构差异在功能上是沉默的,因为r-核心能够以与蛋白水解结构域相同的效率还原细胞色素c。