Download or read book Nickel Amine imine and Amine amide Bisthiolate Complexes as Models for the Active Site of Nickel Superoxide Dismutase written by Nilmini K. Senaratne and published by . This book was released on 2017 with total page 199 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nickel Superoxide Dismutase (NiSOD) catalyzes disproportionation of cytotoxic superoxide radical to H2O2 and molecular O2. The mononuclear nickel center in the active site undergoes alternate oxidation and reduction during the catalytic cycle and, the coordination geometry around the Ni changes accordingly. The four-coordinate reduced state of the NiSOD is coordinated by the N-terminal amine of His1, carboxamido N of Cys2 and, two thiolato S atoms from Cys2 and Cys6 in a square-planar geometry. The oxidized state contains an additional N donor arise from the imidazole of His1 giving a five-coordinate square-pyramidal geometry. The highly unusual coordination environment of the NiSOD makes it distinct among other known SODs and motivates researchers to study about it. This research is mainly focused on to understand the role of the amide N coordination in the NiSOD which is only found in very few metalloenzymes. Through a synthetic model approach we have synthesized two types of model systems which contain amine/amide and amine/imine bisthiolate coordination. The imidazole N from His is the common N donor found in metalloenzymes and we made imine N containing models to represent the normal His imidazole N. The imine containing complexes, [Ni(NNimS]SR] were compared with the amide containing complexes, [Ni(NNamS)SR] utilizing X-ray crystallography, spectroscopic techniques, electrochemical measurements, and reactivity studies. Different thiolates with varying electron donating ability were used to study the effect of nature of the thiolates on the properties of the Ni center. This comparison allows us to understand the effective role of the amide N donation in NiSOD. In addition to our attempts at synthesizing four-coordinate NiN2S2 model complexes, this work describes our attempts at synthesizing NiN3S2 complexes as models for the oxidized state of the NiSOD.
Download or read book Modeling the Structure and Mechanism of Nickel Superoxide Dismutase written by Huaibo Ma and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Part 1 Nickel Superoxide Dismutase Part 2 Computational Studies of Metallothiolate Complexes written by Peter A. Bryngelson and published by . This book was released on 2006 with total page 279 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigations on the Mechanism of Nickel Superoxide Dismutase Using Peptide Based Model Systems written by Daniel Tietze and published by . This book was released on 2010 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spectroscopic and Computational Investigation of Ni Superoxide Dismutase and Fe II dependent Thiol Dioxygenases written by Stephanie Lu Dillon and published by . This book was released on 2017 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transition metal-dependent enzymes are capable of catalyzing a large range of chemical reactions because of the unique tuning of the active site properties by the protein scaffold. In this dissertation, the geometric and electronic structures of several metalloenzymes have been investigated using a combined spectroscopic and computational approach. Our findings reveal that the insertion of an alanine at the N-terminus of the Ni-dependent superoxide dismutase (to generate Ala0 NiSOD) results in the conversion of the terminal amine to a weakly coordinating amide. This alteration leads to the instability of Ala0 Ni(II)SOD upon long-term exposure to air, likely because of the increase in sulfur orbital character in the singly-occupied molecular orbital in the one electron oxidized, Ni(III)-bound species. Mononuclear non-heme Fe(II)-dependent thiol dioxygenases, including cysteine dioxygenase (CDO), mercaptopropionate dioxygenase (MDO), and cysteamine dioxygenase (ADO), were also investigated. The nature of the Fe-S bonding interaction in CDO incubated with various substrate (analogues) was evaluated to determine the origin of the remarkable specificity these enzymes display. Despite the similarities in the computed electronic structures of the active site models for substrate (analogue)-bound CDO, our spectroscopic results reveal that tight binding to the Fe(II) center is impeded when cysteamine and homocysteine are used as a substrate. These results suggest that important interactions with secondary sphere residues dictate substrate specificity. In the case of MDO, our spectroscopic and computational results suggest that 3-mercaptopropionic acid (3MPA) binds in a monodentate fashion via coordination from its sulfur. A computational analysis of various active site models indicates that a solvent-derived water molecule likely occupies the fifth coordination site in 3MPA-bound Fe(II)MDO. Cysteamine dioxygenase (ADO) is the only other mammalian thiol dioxygenase beyond CDO. A quantum mechanic/molecular mechanic (QM/MM) optimized homology model and spectroscopic results provide evidence that ADO also features a 3-histidine facial triad, like CDO and MDO. Despite this similar active site coordination environment, our spectroscopic results obtained for ADO incubated with various substrate (analogues) are distinctly different from those obtained for the other Fe(II)-dependent thiol dioxygenases. This finding suggests that the secondary coordination sphere of ADO is distinct from those of CDO and MDO.
Download or read book Transition Metal Diphenolate and Dithiophenolate Complexes as Synthetic Analogues of the Active Sites of Nickel Superoxide Dismutase and Galactose Oxidase written by George Marshall and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 2 Oxoglutarate Dependent Oxygenases written by Christopher J Schofield and published by Royal Society of Chemistry. This book was released on 2015-05-06 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the discovery of the first examples of 2-oxoglutarate-dependent oxygenase-catalysed reactions in the 1960s, a remarkably broad diversity of alternate reactions and substrates has been revealed, and extensive advances have been achieved in our understanding of the structures and catalytic mechanisms. These enzymes are important agrochemical targets and are being pursued as therapeutic targets for a wide range of diseases including cancer and anemia. This book provides a central source of information that summarizes the key features of the essential group of 2-oxoglutarate-dependent dioxygenases and related enzymes. Given the numerous recent advances and biomedical interest in the field, this book aims to unite the latest research for those already working in the field as well as to provide an introduction for those newly approaching the topic, and for those interested in translating the basic science into medicinal and agricultural benefits. The book begins with four broad chapters that highlight critical aspects, including an overview of possible catalytic reactions, structures and mechanisms. The following seventeen chapters focus on carefully selected topics, each written by leading experts in the area. Readers will find explanations of rapidly evolving research, from the chemistry of isopenicillin N synthase to the oxidation mechanism of 5-methylcytosine in DNA by ten-eleven-translocase oxygenases.
Download or read book Homogeneous Hydrogenation with Non Precious Catalysts written by Johannes F. Teichert and published by John Wiley & Sons. This book was released on 2020-02-03 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: A guide and comprehensive review of the most recent advances in homogeneous hydrogenation with non-precious catalysts In recent years a great deal of research has been applied to homogeneous hydrogenation with non-precious catalysis. Homogeneous Hydrogenation with Non-Precious Catalysts offers a review of the latest developments and advances in the field. In addition, the book explores the transition metal catalysis and the concept of frustrated-lewis-pair (FLP) and enzymatic processes. The editor?a noted expert on the topic?discusses the various catalysts and puts the focus on the synthetic vantage point, highlighting the functional group transformation enabled by the respective catalyst. Homogeneous Hydrogenation with Non-Precious Catalysts also presents the industrial view of the topic and includes an overview of the various catalysts by functional group transformations. This important book: -Offers a comprehensive presentation of the newest development in this emerging field -Highlights the transition metal catalysis, the frustrated-lewis-pair (FLP) concept, and enzymatic processes -Provides an industrial perspective of the topic -Includes an overview of the various catalysis by functional group transformations Written for organic chemists, researchers in synthetic chemistry, and industry professionals, Homogeneous Hydrogenation with Non-Precious Catalysts offers a comprehensive and accessible guide to the most recent advances in the field. [/COPY_WEB_CATALOG]
Download or read book Metal Complexes in Aqueous Solutions written by Arthur E. Martell and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 259 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stability constants are fundamental to understanding the behavior of metal ions in aqueous solution. Such understanding is important in a wide variety of areas, such as metal ions in biology, biomedical applications, metal ions in the environment, extraction metallurgy, food chemistry, and metal ions in many industrial processes. In spite of this importance, it appears that many inorganic chemists have lost an appreciation for the importance of stability constants, and the thermodynamic aspects of complex formation, with attention focused over the last thirty years on newer areas, such as organometallic chemistry. This book is an attempt to show the richness of chemistry that can be revealed by stability constants, when measured as part of an overall strategy aimed at understanding the complexing properties of a particular ligand or metal ion. Thus, for example, there are numerous crystal structures of the Li+ ion with crown ethers. What do these indicate to us about the chemistry of Li+ with crown ethers? In fact, most of these crystal structures are in a sense misleading, in that the Li+ ion forms no complexes, or at best very weak complexes, with familiar crown ethers such as l2-crown-4, in any known solvent. Thus, without the stability constants, our understanding of the chemistry of a metal ion with any particular ligand must be regarded as incomplete. In this book we attempt to show how stability constants can reveal factors in ligand design which could not readily be deduced from any other physical technique.
Download or read book The F Elements written by Nikolas Kaltsoyannis and published by . This book was released on 1999 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: The lanthanides and actinides (the f elements) are rarely studied in detail by chemistry undergraduates. More often they appear as an afterthought in bonding, spectroscopy, magnetism, coordination chemistry, and organometallics courses. This is largely because of a lack of an accessible text treating the chemistry of these elements in one cover. Moreover, the placement of lanthanides and actinides in the closing pages of standard inorganic chemistry text books serves to marginalise these elements further. The f elements has therefore been written to fill a gap in the undergraduate chemistry textbook market. It covers much of the fundamental chemistry of the lanthanide and actinide elements, including coordination chemistry, solid state compounds, organometallic chemistry, electronic spectroscopy, and magnetism. Many comparisons are made between the chemistry of the lanthanides and actinides and that of the transition elements, which is generally much more familiar to undergraduate chemistry students. The book uses the chemistry of the f elements as a vehicle for the communication of several important chemical concepts that are not usually discussed in detail in undergraduate courses, for example the chemical consequences of relativity and the lanthanide and actinide contractions. Many important modern applications of f element chemistry, e.g. the use of actinides in nuclear power generation and of the lanthanides in magnetic resonance imaging and catalytic converters in motor vehicle exhausts, are also discussed in depth.
Download or read book Comprehensive Coordination Chemistry III written by and published by Elsevier. This book was released on 2021-07-29 with total page 6948 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive Coordination Chemistry III describes the fundamentals of metal-ligand interactions, provides an overview of the systematic chemistry of this class of compounds, and details their importance in life processes, medicine, industry and materials science. This new edition spans across 9 volumes, 185 entries and 6600 printed pages. Comprehensive Coordination Chemistry III is not just an update of the second edition, it includes a significant amount of new content. In the descriptive sections 3-6, emphasis is placed upon material that has appeared in primary and secondary review literature since the previous edition published. The material in other sections is newly written, with an emphasis on modern aspects of coordination chemistry and the latest developments. The metal-ligand interaction is the link between the award of the 1913 Nobel Prize in Chemistry to Alfred Werner, the father of Coordination Chemistry, the 1987 prize for supramolecular chemistry and the 2016 award for molecular machines. The key role of coordination chemistry in the assembly of hierarchical nano- and micro-dimensioned structures lies at the core of these applications and so this Major Reference Work bridges several sub-disciplines of chemistry, thus targeting a truly interdisciplinary audience. Provides the go-to foundational resource on coordination chemistry research, providing insights into future directions of the field Written and edited by renowned academics and practitioners from various fields and regions this authoritative and interdisciplinary work is of interest to a large audience, including coordination, supramolecular and molecular chemists Presents content that is clearly structured, organized and cross-referenced to allow students, researchers and professionals to find relevant information quickly and easily
Download or read book Metal Complex DNA Interactions written by Nick Hadjiliadis and published by John Wiley & Sons. This book was released on 2009-03-30 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal ions and metal complexes have long been recognized ascritically important components of nucleic acid chemistry, both inregulation of gene expression and as promising therapeutic agents.Understanding how metal complexes interact with DNA has become anactive research area at the interface between chemistry, molecularbiology and medicine. Metal Complex - DNA Interactions provides a comprehensiveoverview of this increasingly diverse field, presenting recentdevelopments and the latest research with particular emphasis onmetal-based drugs and metal ion toxicity. The text is divided intofour parts: Basic Structural and Kinetic Aspects: includes chapterson sequence-selective metal binding to DNA and thermodynamicmodels. Medical Applications: focuses on anticancer platinumdrugs, including discussions on DNA repair in antitumor effects ofplatinum drugs and photo-dynamic therapy. DNA-Recognition - Nucleases and Sensor: describesprobes for DNA recognition, artificial restriction agents,metallo-DNAzymes for metal sensing applications and metal iondependent catalysis in nucleic acid enzymes. Toxicological Aspects: deals with structural studies ofmercury–DNA interactions, chromium-induced DNA damage andrepair, and the effect of arsenic and nickel on DNAintegrity. This book will be a valuable resource for academic researchersand professionals from a range of pharmaceutical and chemicalindustries, particularly those involved in the development of newand less toxic anticancer metallo-drugs, and in the field ofenvironmental and toxicological chemistry.
Download or read book Proceedings of the American Chemical Society written by and published by . This book was released on 1917 with total page 1558 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the American Chemical Society written by American Chemical Society and published by . This book was released on 1901 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:
