@article {10100,
	title = {Protein-Assisted Formation of Molybdenum Heterometallic Clusters: Evidence for the Formation of S2MoS2-M-S2MoS2 Clusters with M = Fe, Co, Ni, Cu, or Cd within the Orange Protein},
	journal = {Inorg Chem},
	year = {2017},
	note = {<p>Maiti, Biplab KMaia, Luisa BPauleta, Sofia RMoura, IsabelMoura, Jose J GUnited StatesInorganic chemistryInorg Chem. 2017 Jan 27. doi: 10.1021/acs.inorgchem.6b02906.</p>
},
	month = {Jan 27},
	edition = {2017/01/28},
	abstract = {<p>The Orange Protein (ORP) is a small bacterial protein, of unknown function, that harbors a unique molybdenum/copper (Mo/Cu) heterometallic cluster, [S2MoVIS2CuIS2MoVIS2]3-, noncovalently bound. The apo-ORP is able to promote the formation and stabilization of this cluster, using CuII- and MoVIS42- salts as starting metallic reagents, to yield a Mo/Cu-ORP that is virtually identical to the native ORP. In this work, we explored the ORP capability of promoting protein-assisted synthesis to prepare novel protein derivatives harboring molybdenum heterometallic clusters containing iron, cobalt, nickel, or cadmium in place of the "central" copper (Mo/Fe-ORP, Mo/Co-ORP, Mo/Ni-ORP, or Mo/Cd-ORP). For that, the previously described protein-assisted synthesis protocol was extended to other metals and the Mo/M-ORP derivatives (M = Cu, Fe, Co, Ni, or Cd) were spectroscopically (UV-visible and electron paramagnetic resonance (EPR)) characterized. The Mo/Cu-ORP and Mo/Cd-ORP derivatives are stable under oxic conditions, while the Mo/Fe-ORP, Mo/Co-ORP, and Mo/Ni-ORP derivatives are dioxygen-sensitive and stable only under anoxic conditions. The metal and protein quantification shows the formation of 2Mo:1M:1ORP derivatives, and the visible spectra suggest that the expected {S2MoS2MS2MoS2} complexes are formed. The Mo/Cu-ORP, Mo/Co-ORP, and Mo/Cd-ORP are EPR-silent. The Mo/Fe-ORP derivative shows an EPR S = 3/2 signal (E/D approximately 0.27, g approximately 5.3, 2.5, and 1.7 for the lower M= +/-1/2 doublet, and g approximately 5.7 and 1.7 (1.3 predicted) for the upper M = +/-3/2 doublet), consistent with the presence of either one S = 5/2 FeIII antiferromagnetically coupled to two S = 1/2 MoV or one S = 3/2 FeI and two S = 0 MoVI ions, in both cases in a tetrahedral geometry. The Mo/Ni-ORP shows an EPR axial S = 1/2 signal consistent with either one S = 1/2 NiI and two S = 0 MoVI or one S = 1/2 NiIII antiferromagnetically coupled to two S = 1/2 MoV ions, in both cases in a square-planar geometry. The Mo/Cu-ORP and Mo/Cd-ORP are described as {MoVI-CuI-MoVI} and {MoVI-CdII-MoVI}, respectively, while the other derivatives are suggested to exist in at least two possible electronic structures, {MoVI-MI-MoVI} \&lt;--\&gt; {MoV-MIII-MoV}.</p>
},
	isbn = {1520-510X (Electronic)0020-1669 (Linking)},
	url = {http://www.ncbi.nlm.nih.gov/pubmed/28128558},
	author = {Maiti, B. K. and Maia, L. B. and Pauleta, S. R. and Moura, I and Moura, J J}
}
