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- W2009075583 abstract "The Co(III) complexes of N,N'-bis(2-mercaptophenyl)pyridine-2,6-dicarboxamide (PyPSH(4)), a designed pentadentate ligand with built-in carboxamide and thiolate groups, have been synthesized and studied to gain insight into the role of Cys-S oxidation in Co-containing nitrile hydratase (Co-NHase). Reaction of [Co(NH(3))(5)Cl]Cl(2) with PyPS(4)(-) in DMF affords the thiolato-bridged dimeric Co(III) complex (Et(4)N)(2)[Co(2)(PyPS)(2)] (1). Although the bridged structure is quite robust, reaction of (Et(4)N)(CN) with 1 in acetonitrile affords the monomeric species (Et(4)N)(2)[Co(PyPS)(CN)] (2). Oxidation of 2 with H(2)O(2) in acetonitrile gives rise to a mixture which, upon chromatographic purification, yields K(2)[Co(PyPSO(2)(OSO(2))(CN] (3), a species containing asymmetrically oxidized thiolates. The Co(III) metal center in 3 is coordinated to a S-bound sulfinate and an O-bound sulfonate (OSO(2)) group. Upon oxidation with H(2)O(2), 1 affords an asymmetrically oxidized dimer (Et(4)N)(2)[Co(2)(PyPS(SO(2)))(2)] (4) in which only the terminal thiolates are oxidized to form S-bound sulfinate groups while the bridging thiolates remain unchanged. The thiolato-bridge in 4 is also cleaved upon reaction with (Et(4)N)(CN) in acetonitrile, and one obtains (Et(4)N)(2)[Co(PyPS(SO(2)))(CN)] (5), a species that contains both coordinated thiolate and S-bound sulfinate around Co(III). The structures of 1-4 have been determined. The spectroscopic properties and reactivity of all the complexes have been studied to understand the behavior of the Co(III) site in Co-NHase. Unlike typical Co(III) complexes with bound CN(-) ligands, the Co(III) centers in 2 and 5 are labile and rapidly lose CN(-) in aqueous solutions. Since 3 does not show this lability, it appears that at least one thiolato sulfur donor is required in the first coordination sphere for the Co(III) center in such species to exhibit lability. Both 2 and 5 are converted to the aqua complexes [Co(PyPS)(H(2)O)](-) and [Co(PyPS(SO(2))(H(2)O)](-) in aqueous solutions. The pK(a) values of the bound water in these two species, determined by spectrophotometry, are 8.3 +/- 0.03 and 7.2 +/- 0.06, respectively. Oxidation of the thiolato sulfur (to sulfinate) therefore increases the acidity of the bound water. Since 2 and 5 promote hydrolysis of acetonitrile at pH values above their corresponding pK(a) values, it is also evident that a metal-bound hydroxide is a key player in the mechanism of hydrolysis by these model complexes of Co-NHase. The required presence of a Cys-sulfinic residue and one water molecule at the Co(III) site of Co-NHase as well as the optimal pH of the enzyme near 7 suggests that (i) modulation of the pK(a) of the bound water molecule at the active site of the enzyme could be one role of the oxidized Cys-S residue(s) and (ii) a cobalt-bound hydroxide could be responsible for the hydrolysis of nitriles by Co-NHase." @default.
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- W2009075583 date "2003-08-13" @default.
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- W2009075583 title "Modulation of the p<i>K</i><sub>a</sub> of Metal-Bound Water via Oxidation of Thiolato Sulfur in Model Complexes of Co(III) Containing Nitrile Hydratase: Insight into Possible Effect of Cysteine Oxidation in Co−Nitrile Hydratase" @default.
- W2009075583 cites W1964861077 @default.
- W2009075583 cites W1971509230 @default.
- W2009075583 cites W1974493671 @default.
- W2009075583 cites W1974862644 @default.
- W2009075583 cites W1978280518 @default.
- W2009075583 cites W1982166684 @default.
- W2009075583 cites W1983370850 @default.
- W2009075583 cites W1983763187 @default.
- W2009075583 cites W1983777334 @default.
- W2009075583 cites W1985704056 @default.
- W2009075583 cites W1996547536 @default.
- W2009075583 cites W1999129981 @default.
- W2009075583 cites W2010332601 @default.
- W2009075583 cites W2016799062 @default.
- W2009075583 cites W2020223323 @default.
- W2009075583 cites W2021297700 @default.
- W2009075583 cites W2023613563 @default.
- W2009075583 cites W2024541714 @default.
- W2009075583 cites W2029190473 @default.
- W2009075583 cites W2030581562 @default.
- W2009075583 cites W2035945771 @default.
- W2009075583 cites W2039895023 @default.
- W2009075583 cites W2040956342 @default.
- W2009075583 cites W2041556431 @default.
- W2009075583 cites W2044261506 @default.
- W2009075583 cites W2053445234 @default.
- W2009075583 cites W2054051158 @default.
- W2009075583 cites W2061959350 @default.
- W2009075583 cites W2063288157 @default.
- W2009075583 cites W2063707614 @default.
- W2009075583 cites W2066625233 @default.
- W2009075583 cites W2066911891 @default.
- W2009075583 cites W2073146465 @default.
- W2009075583 cites W2073385989 @default.
- W2009075583 cites W2073476142 @default.
- W2009075583 cites W2075896710 @default.
- W2009075583 cites W2087200466 @default.
- W2009075583 cites W2087642816 @default.
- W2009075583 cites W2087890020 @default.
- W2009075583 cites W2093997160 @default.
- W2009075583 cites W2095188041 @default.
- W2009075583 cites W2102708272 @default.
- W2009075583 cites W2150269465 @default.
- W2009075583 cites W2167562686 @default.
- W2009075583 cites W2277843176 @default.
- W2009075583 cites W2949147322 @default.
- W2009075583 cites W2949599730 @default.
- W2009075583 cites W2949726077 @default.
- W2009075583 cites W2949913820 @default.
- W2009075583 cites W2950577362 @default.
- W2009075583 cites W2952419460 @default.
- W2009075583 cites W4211188006 @default.
- W2009075583 cites W4250219574 @default.
- W2009075583 cites W4251277188 @default.
- W2009075583 doi "https://doi.org/10.1021/ic030088s" @default.
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