Download or read book Spectroscopic and Computational Studies of Adenosylcobalamin dependent Enzymes and Their B12 Cofactors written by Amanda June Brooks and published by . This book was released on 2006 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Coenzyme B12 Enzymes Part B written by and published by Academic Press. This book was released on 2022-05-27 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coenzyme B12 Enzymes, Part B, Volume 169 in the Methods in Enzymology series, highlights new advances in the field, with this new volume presenting interesting chapters on Structural characterization of cobalamin-dependent radical SAM methylases, Purification and characterization of sequential cobalamin-dependent radical SAM methylases ThnK and TokK in -lactam antibiotic biosynthesis, Characterization of the cobalamin-dependent radical S-adenosyl-L-methionine enzyme C-methyltransferase Fom3 in fosfomycin biosynthesis, Studies of OxsB and GenK, two B12-dependent radical SAM enzymes involved in natural product biosynthesis, Purification and structural elucidation of the cobalamin-dependent radical SAM enzyme OxsB, and more. Other chapters discuss Methods for studying the mechanisms of B12 enzymes, Computational investigations of B12 dependent enzymatic reactions, Using kinetic isotope effects to probe the mechanisms of adenosylcobalamin-dependent enzymes, Steady-state and pre-steady state kinetic analysis of ornithine 4,5-aminomutase, and more. - Provides the authority and expertise of leading contributors from an international board of authors - Presents the latest release in Methods in Enzymology series - Includes the latest information on B12 Enzymes
Download or read book Combined Spectroscopic and Computational Studies of Free and Enzyme bound B12 Species written by Laura Dynan Elmendorf and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vitamin B12 and its derivatives, known collectively as cobalamins (Cbls) or the B12 family, play an essential role in catalyzing a diverse range of reactions across all areas of life. Understanding the versatile reactivity of these cofactors requires a detailed understanding of their geometric and electronic structures, as well as how these change upon enzyme binding and the addition of substrates. Spectroscopic techniques like electronic absorption, resonance Raman (rRaman), and magnetic circular dichroism spectroscopies are invaluable in this area, particularly when combined with computational techniques such as density functional theory that can bridge the gap between spectral features and structural implications. This dissertation presents a collection of projects that used these methods to delve into the properties and reactivity of free and enzyme-bound B12 species, as well as the mononuclear non-heme iron enzyme cysteamine dioxygenase (ADO). This work includes a study of vibronic coupling in vitamin B12, which afforded new insight into the choice of functional for quantum mechanical modeling of B12 and enabled the identification of the elusive Co-C stretching mode in this molecule's rRaman spectrum. It also includes an investigation of Co-C bond activation in ethanolamine ammonia-lyase (EAL), an adenosylcobalamin (AdoCbl)-dependent enzyme that catalyzes the conversion of ethanolamine to acetaldehyde and an ammonium ion. As with other AdoCbl-dependent enzymes, EAL's catalytic cycle begins with homolytic cleavage of the cofactor's Co-C bond, and the rate of homolysis is increased by 12 orders of magnitude when the cofactor is enzyme-bound in the presence of substrate. We identified conformational changes and cofactor-protein electrostatic interactions that occur upon substrate binding as key factors for promoting controlled and dramatically accelerated Co-C bond homolysis. Finally, two computational studies of PduO-type adenosyltransferases (ATRs), one with the native cobalamin substrate and the other with a rhodium-substituted analogue, explored key steps of the enzyme's catalytic cycle.
Download or read book Characterization of the Enzyme bound Forms of Cobalamins Using Spectroscopy and Computations written by and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: While structural information is available for many cobalamin-dependent enzymes, their catalytic mechanisms remain to be completely elucidated. Notably, spectroscopic characterization of these enzymes in the presence of their B12 cofactors and corresponding substrates is lacking. Magnetic circular dichroism and electronic paramagnetic spectroscopies in particular provide a sensitive probe of cobalamins in their reduced states. As reduced cobalamins are required in the catalytic cycles of ACATs, spectroscopic methods employed in conjunction with computational modeling provide novel insights into the mechanism of these enzymes. Chapter 1 highlights the main aspects of cobalamin chemistry and summarizes recent crystallographic efforts of B12-dependent enzymes. Chapter 2 presents the spectroscopic characterization of nitrosylcobalamin (NOCbl), a recently crystallized form of cobalamin implicated in the nitric oxide cycle and in the inactivation of cobalamin-dependent enzymes. Chapter 3 presents the spectroscopic characterization of Co(II)rrinoids bound to the active site of the CobA ACAT, involved in scavenging and the de novo synthesis of AdoCbl in Salmonella enterica. Our spectroscopic methods allow for determination of the five-coordinate to four-coordinate Co(II)rrinoid equilibrium formed by various CobA variants. In conjunction with crystallographic data and computational modeling, our results provide molecular level information on how CobA facilitates the formation of the Co(I)Cbl supernucleophile required in the catalytic cycle. Chapters 4 and 5 present spectroscopic characterization of the Co(II)Cbl in the active site of the EutT ACAT from Salmonella enterica involved in the catabolism of ethanolamine. EutT is purported to contain a divalent transition metal ion critical in maintaining catalytic function, however no crystal structure of this enzyme or related homologues is available. Specifically, chapter 4 presents spectroscopic studies of Co(II)Cbl in the presence of Fe2+ and Zn2+ containing forms of the wild-type EutT enzyme and selected variants, aimed at elucidating the role of specific amino acids in the putative metal binding site on the formation of Co(I)Cbl species. Chapter 5 presents the spectroscopic characterization of Co2+ containing EutT, disclosing the structure of the divalent metal binding site and the presence of protein-derived cysteine residues serving as ligands.
Download or read book EPR Spectroscopic and Computational Studies of the Paramagnetic Intermediates in the Reaction of Ethanolamine Ammonia Lyase with Ethanolamine written by G̈üneş Bender and published by . This book was released on 2008 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Molecular Modelling of Vitamin B12 and Its Analogues written by Penny Govender and published by CRC Press. This book was released on 2021-09-23 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: For many years, the chemistry of vitamin B12 and its derivatives has been investigated for their inherent eco-friendly and nontoxic nature. This vitamin, also known as cobalamin, is an organic complex that contains a cobalt ion in its structure. Its derivatives are vital bio-inorganic cofactors and possess complex and rich photolytic properties, facilitated by their excited states. This book compiles and details cutting-edge research in the application of vitamin B12 as an environmentally benign catalyst for several organic reactions. It discusses the recent advances and current understanding of the photolytic properties of vitamin B12 derivatives from the perspective of the density functional theory (DFT). The book is of interest for anyone involved in nanotechnology, macromolecular science, cancer, and drug-delivery research.
Download or read book Metal Carbon Bonds in Enzymes and Cofactors written by Astrid Sigel and published by Walter de Gruyter GmbH & Co KG. This book was released on 2015-07-24 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt: The occurrence of a wide variety of metal-carbon bonds in living organisms, ranging from bacteria to humans, is only recently recognized. Of course, the historical examples are the B12 coenzymes containing cobalt-carbon bonds, but now such bonds are also known for nickel, iron, copper, and other transition metal ions. There is no other comparable book; MILS-6, written by 17 experts, summarizes the most recent insights into this fascinating topic.
Download or read book Spectroscopic and Computational Insights Into the Cofactor Activation Mechanism of Cobalamin dependent Methionine Synthase written by Matthew D. Liptak and published by . This book was released on 2008 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transition Metals in Coordination Environments written by Ewa Broclawik and published by Springer. This book was released on 2019-03-16 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the electronic properties of transition metals in coordination environments. These properties are responsible for the unique and intricate activity of transition metal sites in bio- and inorganic catalysis, but also pose challenges for both theoretical and experimental studies. Written by an international group of recognized experts, the book reviews recent advances in computational modeling and discusses their interplay using experiments. It covers a broad range of topics, including advanced computational methods for transition metal systems; spectroscopic, electrochemical and catalytic properties of transition metals in coordination environments; metalloenzymes and biomimetic compounds; and spin-related phenomena. As such, the book offers an invaluable resource for all researchers and postgraduate students interested in both fundamental and application-oriented research in the field of transition metal systems.
Download or read book Coherent Multidimensional Spectroscopy written by Minhaeng Cho and published by Springer. This book was released on 2019-08-06 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book will fulfill the needs of time-domain spectroscopists who wish to deepen their understanding of both the theoretical and experimental features of this cutting-edge spectroscopy technique. Coherent Multidimensional Spectroscopy (CMDS) is a state-of-the-art technique with applications in a variety of subjects like chemistry, molecular physics, biochemistry, biophysics, and material science. Due to dramatic advancements of ultrafast laser technologies, diverse multidimensional spectroscopic methods utilizing combinations of THz, IR, visible, UV, and X-ray radiation sources have been developed and used to study real time dynamics of small molecules in solutions, proteins and nucleic acids in condensed phases and membranes, single and multiple excitons in functional materials like semiconductors, quantum dots, and solar cells, photo-excited states in light-harvesting complexes, ions in battery electrolytes, electronic and conformational changes in charge or proton transfer systems, and excess electrons and protons in water and biological systems.
Download or read book Radical SAM Enzymes written by and published by Academic Press. This book was released on 2018-08-09 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radical SAM Enzymes, Volume 606, the latest release in the Methods in Enzymology series, highlights new advances in the field, with this new volume presenting interesting chapters on the Characterization of the glycyl radical enzyme choline trimethylamine-lyase and its radical S-adenosylmethionine activating enzyme, Diphathimide biosynthesis, Radical SAM glycyl radical activating enzymes, Radical SAM enzyme BioB in the biosynthesis of biotin, Biogenesis of the PQQ cofactor, Role of MoaAC in the biogenesis of the molybdenum cofactor, Biosynthesis of the nitrogenase cofactor, Bioinformatics of the radical SAM superfamily, The involvement of SAM radical enzymes in the biosynthesis of methanogenic coenzymes, methanopterin and coenzyme F420, and more.
Download or read book Journal written by American Chemical Society and published by . This book was released on 2004 with total page 1174 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adenosylcorriniods written by Nicole Roswitha Buan and published by . This book was released on 2005 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies of Solvent Effects on Reaction Dynamics Using Ultrafast Transient Absorption Spectroscopy written by Don Ahmasi Harris and published by . This book was released on 2006 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemistry and Biochemistry of B12 written by Ruma Banerjee and published by John Wiley & Sons. This book was released on 1999-11-03 with total page 960 pages. Available in PDF, EPUB and Kindle. Book excerpt: A Definitive New Reference for the Latest Advances in B_12 Chemistry and Biochemistry Over the past decade, the field of B_12 research has been revolutionized by such major breakthroughs as the unraveling of the entire biosynthetic pathway for this important vitamin. This comprehensive compendium surveys the wealth of information that has accumulated, covering in one volume virtually all aspects of the field-from physical and inorganic chemistry to enzymology, microbiology, medicine, and diagnostic and therapeutic applications. Edited by Dr. Ruma Banerjee, a highly respected and active member of the B_12 community, this work provides B_12 researchers with a dependable and up-to-date reference on the subject. Leading authorities from five continents explore such new areas as the structural biology of B_12-dependent enzymes, free-radical-mediated reaction mechanisms, biosynthesis, and much more. The role of B_12 in nutrition and disease, and B_12 transport, are also thoroughly examined. Complete with color illustrations and extensive references, Chemistry and Biochemistry of B_12 is a one-of-a-kind resource for biochemists, biophysicists, spectroscopists, microbiologists, molecular biologists, and anyone with an interest in "nature's most beautiful cofactor."
Download or read book Comprehensive Natural Products III written by and published by Elsevier. This book was released on 2020-07-22 with total page 4266 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive Natural Products III, Third Edition, Seven Volume Set updates and complements the previous two editions, including recent advances in cofactor chemistry, structural diversity of natural products and secondary metabolites, enzymes and enzyme mechanisms and new bioinformatics tools. Natural products research is a dynamic discipline at the intersection of chemistry and biology concerned with isolation, identification, structure elucidation, and chemical characteristics of naturally occurring compounds such as pheromones, carbohydrates, nucleic acids and enzymes. This book reviews the accumulated efforts of chemical and biological research to understand living organisms and their distinctive effects on health and medicine and to stimulate new ideas among the established natural products community. Provides readers with an in-depth review of current natural products research and a critical insight into the future direction of the field Bridges the gap in knowledge by covering developments in the field since the second edition published in 2010 Split into 7 sections on key topics to allow students, researchers and professionals to find relevant information quickly and easily Ensures that the knowledge within is easily understood by and applicable to a large audience
Download or read book Developmental Neurotoxicology Research written by Cheng Wang and published by John Wiley & Sons. This book was released on 2011-04-12 with total page 819 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes how systems biology, pharmacogenomic and behavioral approaches, as applied to neurodevelopmental toxicology, provide a structure to arrange information in a biological model. Authors review and discuss approaches that can be used as effective tools to dissect mechanisms underlying pharmacological and toxicological phenomena associated with the exposure to drugs or environmental toxicants during development. This book presents cross-cutting research tools and animal models, along with applications to the studies associated with potential anesthetic-induced developmental neurotoxicity; the developmental basis of adolescent or adult onset of disease; risk assessment of methyl mercury and its effects on neurodevelopment; challenges in the field to identify environmental factors of relevance to autism; and the strategy and progress of epilepsy research.
