Structures of ruthenium-modified Pseudomonas aeruginosa azurin and [Ru(2,2'-bipyridine)2(imidazole)2]SO4 x 10H2O.
ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 1999;
55:379-85. [PMID:
10089343 DOI:
10.1107/s0907444998010464]
[Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
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.
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