Faham S, Day M W, Connick W B, Crane B R, Di Bilio A J, Schaefer W P, Rees D C, Gray H B
Division of Chemistry and Chemical Engineering, 147-75 CH, California Institute of Technology, Pasadena, California 91125, USA.
Acta Crystallogr D Biol Crystallogr. 1999 Feb;55(Pt 2):379-85. doi: 10.1107/s0907444998010464.
The crystal structure of Ru(2, 2'-bipyridine)2(imidazole)(His83)azurin (RuAz) has been determined to 2.3 A -resolution by X-ray crystallography. The spectroscopic and thermodynamic properties of both the native protein and [Ru(2, 2'-bipyridine)2(imidazole)2]2+ are maintained in the modified protein. Dark-green RuAz crystals grown from PEG 4000, LiNO3, CuCl2 and Tris buffer are monoclinic, belong to the space group C2 and have cell parameters a = 100.6, b = 35.4, c = 74.7 A and beta = 106. 5 degrees. In addition, [Ru(2,2'-bipyridine)2(imidazole)2]SO4 x 10H2O was synthesized, crystallized and structurally characterized by X-ray crystallography. Red-brown crystals of this complex are monoclinic, space group P21/n, unit-cell parameters a = 13.230 (2), b = 18.197 (4), c = 16.126 (4) A, beta = 108.65 (2) degrees. Stereochemical parameters for the refinement of Ru(2, 2'-bipyridine)2(imidazole)(His83) were taken from the atomic coordinates of [Ru(2,2'-bipyridine)2(imidazole)2]2+. The structure of RuAz confirms that His83 is the only site of chemical modification and that the native azurin structure is not perturbed significantly by the ruthenium label.
通过X射线晶体学已将Ru(2, 2'-联吡啶)2(咪唑)(His83)天青蛋白（RuAz）的晶体结构解析至2.3 Å分辨率。天然蛋白质和[Ru(2, 2'-联吡啶)2(咪唑)2]2+的光谱和热力学性质在修饰后的蛋白质中得以保留。从聚乙二醇4000、硝酸锂、氯化铜和Tris缓冲液中生长出的深绿色RuAz晶体为单斜晶系，属于空间群C2，晶胞参数a = 100.6，b = 35.4，c = 74.7 Å，β = 106.5°。此外，合成了[Ru(2,2'-联吡啶)2(咪唑)2]SO4·10H2O，通过X射线晶体学对其进行了结晶和结构表征。该配合物的红棕色晶体为单斜晶系，空间群P21/n，晶胞参数a = 13.230 (2)，b = 18.197 (4)，c = 16.126 (4) Å，β = 108.65 (2)°。Ru(2, 2'-联吡啶)2(咪唑)(His83)细化的立体化学参数取自[Ru(2,2'-联吡啶)2(咪唑)2]2+的原子坐标。RuAz的结构证实His83是唯一的化学修饰位点，并且天然天青蛋白结构未因钌标记而受到显著扰动。
