Modulation of the pKaof 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

2003 ◽  
Vol 42 (18) ◽  
pp. 5751-5761 ◽  
Author(s):  
Laurie A. Tyler ◽  
Juan C. Noveron ◽  
Marilyn M. Olmstead ◽  
Pradip K. Mascharak
Keyword(s):  
Nitrile Hydratase ◽  
Bound Water ◽  
Cysteine Oxidation ◽  
Model Complexes ◽  
Insight Into

Non-Heme Diiron Model Complexes Can Mediate Direct NO Reduction: Mechanistic Insight into Flavodiiron NO Reductases

2018 ◽  
Vol 140 (41) ◽  
pp. 13429-13440 ◽  
Author(s):  
Hai T. Dong ◽  
Corey J. White ◽  
Bo Zhang ◽  
Carsten Krebs ◽  
Nicolai Lehnert
Keyword(s):  
No Reduction ◽  
Model Complexes ◽  
Mechanistic Insight ◽  
Insight Into

scholarly journals Using small molecule complexes to elucidate features of photosynthetic water oxidation

2007 ◽  
Vol 363 (1494) ◽  
pp. 1271-1281 ◽  
Author(s):  
Kristof Meelich ◽  
Curtis M Zaleski ◽  
Vincent L Pecoraro
Keyword(s):  
Water Oxidation ◽  
Spectroscopic Characterization ◽  
Structural Features ◽  
Oxygen Evolving Complex ◽  
Model Complexes ◽  
Small Model ◽  
Oxygen Evolving ◽  
Photosynthetic Water Oxidation ◽  
Insight Into

The molecular oxygen produced in photosynthesis is generated via water oxidation at a manganese–calcium cluster called the oxygen-evolving complex (OEC). While studies in biophysics, biochemistry, and structural and molecular biology are well known to provide deeper insight into the structure and workings of this system, it is often less appreciated that biomimetic modelling provides the foundation for interpreting photosynthetic reactions. The synthesis and characterization of small model complexes, which either mimic structural features of the OEC or are capable of providing insight into the mechanism of O 2 evolution, have become a vital contributor to this scientific field. Our group has contributed to these findings in recent years through synthesis of model complexes, spectroscopic characterization of these systems and probing the reactivity in the context of water oxidation. In this article we describe how models have made significant contributions ranging from understanding the structure of the water-oxidation centre (e.g. contributions to defining a tetrameric Mn 3 Ca-cluster with a dangler Mn) to the ability to discriminate between different mechanistic proposals (e.g. showing that the Babcock scheme for water oxidation is unlikely).

Silicon-Heteroaromatic [FeFe] Hydrogenase Model Complexes: Insight into Protonation, Electrochemical Properties, and Molecular Structures

2015 ◽  
Vol 21 (13) ◽  
pp. 5061-5073 ◽  
Author(s):  
Roman Goy ◽  
Luca Bertini ◽  
Helmar Görls ◽  
Luca De Gioia ◽  
Jean Talarmin ◽  
...  
Keyword(s):  
Electrochemical Properties ◽  
Molecular Structures ◽  
Model Complexes ◽  
Insight Into

Toward a Tunable Synthetic [FeFe]-Hydrogenase H-Cluster Mimic Mediated by Perylene Monoimide Model Complexes: Insight into Molecular Structures and Electrochemical Characteristics

2018 ◽  
Vol 37 (19) ◽  
pp. 3278-3285 ◽  
Author(s):  
Hassan Abul-Futouh ◽  
Artem Skabeev ◽  
Davide Botteri ◽  
Yulian Zagranyarski ◽  
Helmar Görls ◽  
...  
Keyword(s):  
Molecular Structures ◽  
Electrochemical Characteristics ◽  
Model Complexes ◽  
Insight Into

scholarly journals QM/MM computational studies of substrate water binding to the oxygen-evolving centre of photosystem II

2007 ◽  
Vol 363 (1494) ◽  
pp. 1149-1156 ◽  
Author(s):  
Eduardo M Sproviero ◽  
Katherine Shinopoulos ◽  
José A Gascón ◽  
James P McEvoy ◽  
Gary W Brudvig ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
Exchange Rates ◽  
Water Exchange ◽  
Metal Cluster ◽  
Bound Water ◽  
Water Molecules ◽  
Computational Studies ◽  
Water Binding ◽  
Model Complexes ◽  
Oxygen Evolving

This paper reports computational studies of substrate water binding to the oxygen-evolving centre (OEC) of photosystem II (PSII), completely ligated by amino acid residues, water, hydroxide and chloride. The calculations are based on quantum mechanics/molecular mechanics hybrid models of the OEC of PSII, recently developed in conjunction with the X-ray crystal structure of PSII from the cyanobacterium Thermosynechococcus elongatus . The model OEC involves a cuboidal Mn 3 CaO 4 Mn metal cluster with three closely associated manganese ions linked to a single μ 4 -oxo-ligated Mn ion, often called the ‘dangling manganese’. Two water molecules bound to calcium and the dangling manganese are postulated to be substrate molecules, responsible for dioxygen formation. It is found that the energy barriers for the Mn(4)-bound water agree nicely with those of model complexes. However, the barriers for Ca-bound waters are substantially larger. Water binding is not simply correlated to the formal oxidation states of the metal centres but rather to their corresponding electrostatic potential atomic charges as modulated by charge-transfer interactions. The calculations of structural rearrangements during water exchange provide support for the experimental finding that the exchange rates with bulk 18 O-labelled water should be smaller for water molecules coordinated to calcium than for water molecules attached to the dangling manganese. The models also predict that the S 1 →S 2 transition should produce opposite effects on the two water-exchange rates.

scholarly journals Insight into the Maturation Process of the Nitrile Hydratase Active Site

2021 ◽  
Vol 35 (S1) ◽  
Author(s):  
Irene Ogutu ◽  
Richard Holz ◽  
Brian Bennett
Keyword(s):  
Active Site ◽  
Nitrile Hydratase ◽  
Maturation Process ◽  
Insight Into

In search of metal hydrides: an X-ray absorption and emission study of [NiFe] hydrogenase model complexes

2016 ◽  
Vol 18 (16) ◽  
pp. 10688-10699 ◽  
Author(s):  
Stefan Hugenbruch ◽  
Hannah S. Shafaat ◽  
Tobias Krämer ◽  
Mario Ulises Delgado-Jaime ◽  
Katharina Weber ◽  
...  
Keyword(s):  
Metal Hydride ◽  
Quantum Chemical ◽  
Metal Hydrides ◽  
Model Complexes ◽  
X Ray ◽  
Chemical Studies ◽  
Quantum Chemical Studies ◽  
Emission Study ◽  
X Ray Absorption ◽  
Insight Into

Insight into the factors that favor metal–hydride interactions in NiFe-hydrogenase models is obtained through X-ray spectroscopic and quantum chemical studies.

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