T h e r e a c t i v i t y o f c i s - diamminediiodidoplatinum(II), cis-PtI2(NH3)2, the iodo analogue of cisplatin, with hen egg white lysozyme (HEWL) was investigated by electrospray ionization mass spectrometry and X-ray crystallography. Interestingly, the study compound forms a stable 1:1 protein adduct for which the crystal structure was solved at 1.99 Å resolution. In this adduct, the PtII center, upon release of one ammonia ligand, selectively coordinates to the imidazole of His15. Both iodide ligands remain bound to platinum, with this being a highly peculiar and unexpected feature. Notably, two equivalent modes of PtII binding are possible that differ only in the location of I atoms with respect to ND1 of His15. The structure of the adduct was compared with that of HEWL−cisplatin, previously described; differences are stressed and their important mechanistic implications discussed.
Peculiar Features in the Crystal Structure of the Adduct Formed betweencis-PtI2(NH3)2and Hen Egg White Lysozyme / Luigi Messori;Tiziano Marzo;Chiara Gabbiani;Amparo A. Valdes;Adoracion G. Quiroga;Antonello Merlino. - In: INORGANIC CHEMISTRY. - ISSN 0020-1669. - ELETTRONICO. - 52:(2013), pp. 13827-13829. [10.1021/ic402611m]
Peculiar Features in the Crystal Structure of the Adduct Formed betweencis-PtI2(NH3)2and Hen Egg White Lysozyme
MESSORI, LUIGI;MARZO, TIZIANO;
2013
Abstract
T h e r e a c t i v i t y o f c i s - diamminediiodidoplatinum(II), cis-PtI2(NH3)2, the iodo analogue of cisplatin, with hen egg white lysozyme (HEWL) was investigated by electrospray ionization mass spectrometry and X-ray crystallography. Interestingly, the study compound forms a stable 1:1 protein adduct for which the crystal structure was solved at 1.99 Å resolution. In this adduct, the PtII center, upon release of one ammonia ligand, selectively coordinates to the imidazole of His15. Both iodide ligands remain bound to platinum, with this being a highly peculiar and unexpected feature. Notably, two equivalent modes of PtII binding are possible that differ only in the location of I atoms with respect to ND1 of His15. The structure of the adduct was compared with that of HEWL−cisplatin, previously described; differences are stressed and their important mechanistic implications discussed.I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.