Metallohydrolase biomimetics with catalytic and structural flexibility

Mendes, Luisa L., Englert, Daniel, Fernandes, Christiane, Gahan, Lawrence R., Schenk, Gerhard and Horn, Adolfo Jr. (2016) Metallohydrolase biomimetics with catalytic and structural flexibility. Dalton Transactions, 45 46: 18510-18521. doi:10.1039/c6dt03200a


Author Mendes, Luisa L.
Englert, Daniel
Fernandes, Christiane
Gahan, Lawrence R.
Schenk, Gerhard
Horn, Adolfo Jr.
Title Metallohydrolase biomimetics with catalytic and structural flexibility
Journal name Dalton Transactions   Check publisher's open access policy
ISSN 1477-9226
1477-9234
Publication date 2016-09-27
Year available 2016
Sub-type Article (original research)
DOI 10.1039/c6dt03200a
Open Access Status Not yet assessed
Volume 45
Issue 46
Start page 18510
End page 18521
Total pages 12
Place of publication Cambridge, United Kingdom
Publisher Royal Society of Chemistry
Language eng
Abstract The structural and functional properties of zinc(II) complexes of two nitrogen rich polydentate ligands, HTPDP = 1,3-bis(bis-pyridin-2-ylmethylamino) propan-2-ol and HTPPNOL = N,N,N'-tris-(2-pyridylmethyl)-1,3- diaminopropan-2-ol, are compared. HTPDP is a hepta-dentate ligand with four pyridyl groups attached to a 1,3- diaminopropan-2-ol backbone while HTPPNOL contains only three pyridyl groups. In reactions with Zn(ClO4)(2),HTPDP forms a dinuclear zinc compound [Zn-2(TPDP)(OAc)](ClO4)(2), 1. On the other hand, mononuclear [Zn(HTPPNOL)](ClO4)(2), 2, and tetranuclear [Zn-4(TPPNOL)(2)(OAc)(3)] (ClO4)(3,) 3, complexes were isolated with the ligand HTPPNOL. Kinetic measurements with the substrate bis(2,4-dinitrophenyl) phosphate (BDNPP) revealed that compound 1 (k(cat) = 31.4 x 10(-3) min(-1)) is more reactive than 3 (k(cat) = 7.7 x 10(-3) min(-1)) at pH = 8.5, whilst the mononuclear compound 2 is inactive. Compound 1 displays a typical steady-state kinetic behaviour, while compound 3 exhibits steady-state behaviour only similar to 120 s after starting the reaction, preceded by a burst-phase. P-31 NMR studies confirm that 1 can promote the hydrolysis of both ester bonds in BDNPP, generating the monoester DNPP and inorganic phosphate in the process. In contrast, DNPP is not a substrate for 3. The crystal structure of the complex formed by 3 and DNPP reveals the formation of a tetranuclear zinc complex [Zn-4(TPPNOL)(2)(DNPP) 2](ClO4)(2), 4, in which the phosphate moiety of DNPP adopts an unusual tridentate mu-eta(1):eta(1):eta(1)coordination mode.
Formatted abstract
The structural and functional properties of zinc(II) complexes of two nitrogen rich polydentate ligands, HTPDP = 1,3-bis(bis-pyridin-2-ylmethylamino)propan-2-ol and HTPPNOL = N,N,N′-tris-(2-pyridylmethyl)-1,3-diaminopropan-2-ol, are compared. HTPDP is a hepta-dentate ligand with four pyridyl groups attached to a 1,3-diaminopropan-2-ol backbone while HTPPNOL contains only three pyridyl groups. In reactions with Zn(ClO4)2, HTPDP forms a dinuclear zinc compound [Zn2(TPDP)(OAc)](ClO4)2, 1. On the other hand, mononuclear [Zn(HTPPNOL)](ClO4)2, 2, and tetranuclear [Zn4(TPPNOL)2(OAc)3](ClO4)3, 3, complexes were isolated with the ligand HTPPNOL. Kinetic measurements with the substrate bis(2,4-dinitrophenyl)phosphate (BDNPP) revealed that compound 1 (kcat = 31.4 × 10−3 min−1) is more reactive than 3 (kcat = 7.7 × 10−3 min−1) at pH = 8.5, whilst the mononuclear compound 2 is inactive. Compound 1 displays a typical steady-state kinetic behaviour, while compound 3 exhibits steady-state behaviour only ∼120 s after starting the reaction, preceded by a burst-phase. 31P NMR studies confirm that 1 can promote the hydrolysis of both ester bonds in BDNPP, generating the monoester DNPP and inorganic phosphate in the process. In contrast, DNPP is not a substrate for 3. The crystal structure of the complex formed by 3 and DNPP reveals the formation of a tetranuclear zinc complex [Zn4(TPPNOL)2(DNPP)2](ClO4)2, 4, in which the phosphate moiety of DNPP adopts an unusual tridentate μ–η111 coordination mode.
Keyword Chemistry, Inorganic & Nuclear
Chemistry
Q-Index Code C1
Q-Index Status Provisional Code
Grant ID 406749/2013-2
99999.006336/2014-00
DP150104358
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: HERDC Pre-Audit
School of Chemistry and Molecular Biosciences
 
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Created: Fri, 18 Nov 2016, 20:36:23 EST by Mrs Louise Nimwegen on behalf of School of Chemistry & Molecular Biosciences