Reactions Involving the Heme Proteins Cytochrome C and Cytochrome C Peroxidase
Author: Karen Taylor Conklin
Publisher:
Published: 1987
Total Pages: 211
ISBN-13:
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Author: Karen Taylor Conklin
Publisher:
Published: 1987
Total Pages: 211
ISBN-13:
DOWNLOAD EBOOKAuthor: Suong Thao Tran
Publisher:
Published: 1995
Total Pages: 252
ISBN-13:
DOWNLOAD EBOOKAuthor: Heather A. Kilheeney
Publisher:
Published: 2016
Total Pages: 106
ISBN-13: 9781369537895
DOWNLOAD EBOOKAttention has been given to the peroxygenase activity of heme proteins, the incorporation of an oxygen atom from hydrogen peroxide into an organic substrate. The peroxygenase reaction eliminates the need for NADH or NADPH and the P450 reductase. Although peroxygenation is not a typical reaction catalyzed by heme enzymes, many heme proteins have low levels of peroxygenase activity. This thesis explores the peroxygenase activity of the well-studied heme protein, cytochrome c peroxidase (CcP). CcP is an ideal candidate for exploring the peroxygenase activity of heme proteins and for the development of robust peroxygenation catalysts since it reacts rapidly with hydrogen peroxide and is very stable toward oxidative degradation. Protein engineering studies allow us to enhance the peroxygenase activity of CcP by creating a more apolar environment to facilitate the binding of organic substrates near the heme. Three CcP mutants with apolar heme pockets were constructed by converting Arg48, Trp51, and His52 simultaneously to all alanines (CcP(triAla)), all valines (CcP(triVal)), or all leucines (CcP(triLeu)). Styrene and acrylonitrile epoxidation reactions and 1-methoxynaphthalene hydroxylation reactions were studied using wild-type CcP and CcP mutants to investigate the peroxygenase activity of these enzymes. CcP Compound I oxidizes styrene and acrylonitrile with observed bimolecular rate constants of (4.6 +/- 4.1) x 10 -4 M-1 s-1 and (4.3 +/- 0.3) x 10-3 M-1 s-1, respectively. The rate of the peroxygenation of acrylonitrile catalyzed by CcP is similar to that of the monooxygenase oxidation reaction of acrylonitrile catalyzed by rat liver microsomal P450. The CcP triple mutants hydroxylate 1-methoxynapthalene at rates that are about 30 times faster than wild-type CcP. However, the turnover rates of 0.13 to 0.15 min-1 are small when compared with the 103 min-1 rates of the monoxygenase activity of some bacterial P450s. A fourth CcP mutant, meant to mimic the heme coordination of cytochrome P450, CcP(H175C/D235L), had a smaller rate of naphthalene hydroxylation than the CcP triple mutants. Unfortunately, all of the CcP mutants had increased rates of heme degradation during the hydroxylation reaction compared to wild-type CcP. Further development of CcP as a peroxygenation catalyst will need to focus on the stability of the enzyme as well as increasing the rate of substrate turnover. (Abstract shortened by ProQuest.).
Author: Emma Raven
Publisher: Royal Society of Chemistry
Published: 2015-10-27
Total Pages: 388
ISBN-13: 1849739110
DOWNLOAD EBOOKThis book will provide an up to date handbook that is unique in its combination of both the general aspects of heme protein structure and the function in a single volume.
Author: Ivano Bertini
Publisher: University Science Books
Published: 2007
Total Pages: 794
ISBN-13: 9781891389436
DOWNLOAD EBOOKPart A.: Overviews of biological inorganic chemistry : 1. Bioinorganic chemistry and the biogeochemical cycles -- 2. Metal ions and proteins: binding, stability, and folding -- 3. Special cofactors and metal clusters -- 4. Transport and storage of metal ions in biology -- 5. Biominerals and biomineralization -- 6. Metals in medicine. -- Part B.: Metal ion containing biological systems : 1. Metal ion transport and storage -- 2. Hydrolytic chemistry -- 3. Electron transfer, respiration, and photosynthesis -- 4. Oxygen metabolism -- 5. Hydrogen, carbon, and sulfur metabolism -- 6. Metalloenzymes with radical intermediates -- 7. Metal ion receptors and signaling. -- Cell biology, biochemistry, and evolution: Tutorial I. -- Fundamentals of coordination chemistry: Tutorial II.
Author: Eddy Tsun-Cheong Cheung
Publisher:
Published: 1992
Total Pages:
ISBN-13:
DOWNLOAD EBOOKAuthor: H.A.O. Hill
Publisher: Springer Science & Business Media
Published: 1999-04-01
Total Pages: 222
ISBN-13: 9783540655534
DOWNLOAD EBOOKBiological chemistry is a major frontier of inorganic chemistry. Three special volumes devoted to Metal Sites in Proteins and Models address the questions: how unusual ("entatic") are metal sites in metalloproteins and metalloenzymes compared to those in small coordination complexes? and if they are special, how do polypeptide chains and co-factors control this? The chapters deal with iron, with metal centres acting as Lewis acids, metals in phosphate enzymes, with vanadium, and with the wide variety of transition metal ions which act as redox centres. They illustrate in particular how the combined armoury of genetics and structure determination at the molecular level are providing unprecedented new tools for molecular engineering.
Author: Geoffrey R. Moore
Publisher: Springer Science & Business Media
Published: 2012-12-06
Total Pages: 488
ISBN-13: 3642745369
DOWNLOAD EBOOKCytochromes c are haemoproteins which carry out electron transfer in a wide variety of biological systems, necessitating different kinds of cytochrome c to fulfill different biological roles. The evolutionary relationship between cytochromes c and their host organisms are described, as well as their structural, spectroscopic and redox properties, including both electron-transfer rates and redox potentials. The treatment is aimed at the non-specialist so that both the techniques described and their application to cytochromes c can be understood. All classes of cytochrome c are dealt with to provide a comprehensive account of the field. No other text provides such a broad survey. Similar to the earlier volume "Cytochromes c: Biological Aspects" which deals with the classification, biosynthesis and biological role of cytochromes c, the present book is aimed at research workers and advanced students.
Author: Robert A. Scott
Publisher:
Published: 1996-04-26
Total Pages: 760
ISBN-13:
DOWNLOAD EBOOKOne of the most heavily researched proteins in existence, cytochrome c has proved irresistible to chemists and biophysicists for decades. This volume serves as a source book to update the vast body of literature compiled on this protein over the last 40 years. Chapters from an internationally renowned group of experts provide extensive coverage of structural studies, spectroscopic properties, thermodynamic properties, electron transfer kinetics and protein modification. "... a valuable addition to the cytochrome literature; I will certainly get a copy for my group." Dr G. R. Moore, University of East Anglia "For any and all students of the science of cytochrome c, this is an indispensable text." SIM News
Author: Johannes Everse
Publisher: CRC Press
Published: 1990-10-24
Total Pages: 280
ISBN-13: 9780849369643
DOWNLOAD EBOOKThe second of two relatively independent volumes on the chemistry and biology of peroxidases. Volumes 2 covers the peroxidases isolated from plants and microorganisms, and includes detailed discussions of some of the unique reactions catalyzed by these enzymes. Volume one covered the peroxidases isolated from animal sources, as well as the "pseudo- peroxidase activity" of prostaglandin H synthase and of myoglobin and hemoglobin. Acidic paper. Annotation copyrighted by Book News, Inc., Portland, OR