Biochemical Basis of Oxidative Protein Folding in the Endoplasmic Reticulum PDF Download

Author: Benjamin Peng-Chu Tu
Publisher:
ISBN:
Category :
Languages : en
Pages : 246

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Author: Pumtiwitt C. Rancy
Publisher:
ISBN: 9781124087627
Category : Oxidases
Languages : en
Pages :

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Oxidative protein folding describes the process by which disulfide bonds are inserted into proteins as they fold into their native structure. This involves two distinct phases, an oxidation phase where these covalent linkages are first introduced, and an isomerization phase in which incorrectly placed disulfides are shuffled leading to the native pairings. In eukaryotes, disulfide bond formation can be catalyzed by a number of flavin-dependent sulfhydryl oxidases. This dissertation work investigates how a particular flavin-dependent sulfhydryl oxidase, Quiescin-sulfhydryl oxidase (QSOX), cooperates with protein disulfide isomerase (PDI) to generate native pairings in two unfolded reduced proteins: ribonuclease A (RNase A, four disulfide bonds and 105 disulfide isomers of the fully oxidized protein) and avian riboflavin binding protein (RfBP, nine disulfide bonds and more than 34 million corresponding disulfide pairings). This QSOX/PDI in vitro folding system involves no functional interaction between the two enzymatic components; QSOX inserts disulfide bonds into protein substrates while PDI isomerizes the misplaced pairs to the native ones. Rapid refolding does not require glutathione or glutathione-based redox buffers. Refolding of RfBP is followed continuously by monitoring spectral changes experienced by the ligand, riboflavin, upon binding to the apoprotein. Efficient refolding of this protein only occurs with a large molar excess of reduced PDI over the folding client protein. These conditions likely mirror the environment of the endoplasmic reticulum lumen where small concentrations of nascent proteins are exposed to nearly mM levels of PDI. Subsequent studies performed in the absence of QSOX or redox buffers, explore the effectiveness of mixtures of oxidized and reduced PDI in refolding RfBP. Here, the fastest refolding of RfBP occurs with excess reduced PDI and just enough oxidized PDI to generate nine disulfides in the protein. The implications of these in vitro experiments for understanding oxidative folding processes in vivo are discussed. Although unfolded proteins have been proven to be excellent substrates of QSOX, a recent proposal suggests that it can also function in the generation of inter-domain and inter-protein disulfide bridges, where the substrates are already substantially or completely folded. This suggestion has been tested using wild type and mutant Escherichia coli thioredoxin as a model substrate. These folded substrates are, by comparison, poorly oxidized by QSOX which is consistent with the expected stringent steric requirements for efficient thiol/disulfide exchange reactions.

Author:
Publisher:
ISBN: 9780815332183
Category : Cells
Languages : en
Pages : 0

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Author: Sigrid C. Veasey
Publisher: Springer Science & Business Media
ISBN: 1603273425
Category : Medical
Languages : en
Pages : 224

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Twenty-five years ago, Earl R. Stadtman, PhD discovered that specific enzymes regulating metabolism can be inactivated by oxidation [1]. He later showed that age-related oxidative modification contributes, at least in part, to age-related loss of function of the enzymes [2, 3]. Dr. Stadtman broke the ground for a new field of study to discover how oxidative stress contributes in significant ways to age-related cellular dysfunction and protein accumulation and that oxidation in the aging brain influences Alzheimer’s disease, ischemia-reperfusion injury, amyotrophic lateral sclerosis, and lifespan [4–6]. Today, his research and mentorship have positively influenced the work of hundreds of scientists in this field. We dedicate this book to Dr. Earl R. Stadtman (1912–2008), in celebration of his passion for science and his superior collaborative and mentorship skills. This book is comprised of three sections. The first describes the valuable roles reactive oxygen species (ROS) and reactive nitrogen species (RNS) play in cellular biology. The second section provides an overview of redox imbalance injury with effects on mitochondria, signaling, endoplasmic reticular function, and on aging in general. The third section takes these mechanisms to neurodegenerative disorders and provides a state-of-the-art look at the roles redox imbalances play in age-related susceptibility to disease and in the disease processes. In the first section we attempt to answer a question posed by Dr. Stadtman, ‘‘Why have cells selected reactive oxygen species to regulate cell signaling events’’ [7].

Author: A. Benedetti
Publisher: IOS Press
ISBN: 9781586034740
Category : Medical
Languages : en
Pages : 172

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The endoplasmic reticulum is a continuous membrane network in the cytosol, which encloses its internal compartment, the endoplasmic reticulum lumen. Several metabolic pathways are compartmentalised within the ER lumen, for example hydrolysis of glucose 6-phosphate, glucuronidation of endo- xenobiotics, posttranslational modification of proteins including redox reactions required for oxidative folding, oxidoreduction of steroid hormones, synthesis of ascorbate. Therefore, enzyme activities of these pathways depend on the special luminal microenvironment, on access to substrates and on release of products. However, in spite of great efforts, the molecular mechanism for the generation and maintenance of this special microenvironment still remains to be elucidated. Beside the well-known functions of the endoplasmic reticulum, such as calcium signaling and the synthesis of secretory proteins, recent findings underlined the importance of the intraluminal redox biochemistry and the role of membrane transporters. The field is currently undergoing extensive reappraisal, new transporters have been identified either molecular or functional level.The local synthesis and the membrane transport of redox active compounds (pro- and antioxidants) seem to be important not only in the disulfide bond formation, but also in the generation of intracellular proliferative/apoptotic signals. The different points of views in this publication help highlight the potential importance of several recently described phenomena, whose significance needs elucidation.

Author: Luis Moroder
Publisher: Royal Society of Chemistry
ISBN: 0854041486
Category : Science
Languages : en
Pages : 453

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With contributions from experts in the field, this book provides a comprehensive overview of the oxidative folding of cysteine-rich peptides.

Author: Luis B. Agellon
Publisher: Springer Nature
ISBN: 303067696X
Category : Science
Languages : en
Pages : 329

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Book Description
This book provides a comprehensive overview of the biology of the endoplasmic reticulum (ER) and the associated ER proteins, it discusses their structure, function and signaling mechanisms in the cell and their role in disease. This book also offers insights into the practical aspects of research and demonstrates the use of non-mammalian models to study the structure and function of the ER. Written by leading experts in the field, the book enables readers to gain a thorough understanding of current ER biology. It is intended for scientists and clinical researchers working on the endoplasmic reticulum in all its various roles and facets in health and disease.

Author:
Publisher:
ISBN:
Category : Medicine
Languages : en
Pages : 1748

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Book Description
Vols. for 1963- include as pt. 2 of the Jan. issue: Medical subject headings.

Author: Rowen J. Y. Chang
Publisher: Springer Science & Business Media
ISBN: 1441972730
Category : Science
Languages : en
Pages : 290

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Book Description
This book aims to cover the knowledge of protein folding accumulated from studies of disulfide-containing proteins, including methodologies, folding pathways, and folding mechanism of numerous extensively characterized disulfide proteins. Folding of Disulfide Proteins will be valuable supplementary reading for general biochemistry, biophysics, molecular biology, and cellular biology courses for graduate and undergraduate students. This book can also be used for specialized graduate-level biochemistry, biophysics, and molecular biology courses dedicated to protein folding as well as related biological problems and diseases. Will also be of interest to everybody interested in problems related to protein folding, and anyone who is interested in understanding the mechanism of protein misfolding and protein misfolding-related diseases.

Author: S. E. Rokita
Publisher: John Wiley & Sons
ISBN: 9780470452875
Category : Science
Languages : en
Pages : 456

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Multidisciplinary perspectives and approaches to quinone methides research The Wiley Series on Reactive Intermediates in Chemistry and Biology investigates reactive intermediates from the broadest possible range of disciplines. The contributions in each volume offer readers fresh insights into the latest findings, emerging applications, and ongoing research in the field from a diverse perspective. This inaugural volume in the series, Quinone Methides, represents the first book devoted to this fascinating and useful intermediate. The authors of this work reflect the many disciplines and approaches to quinone methides research. The volume therefore covers a broad range of topics, including theoretical treatments, generation and detection of intermediates, characterization and applications in chemistry and biochemistry, and biological reactivity. Among the chapters are: Photochemical generation and characterization of quinone methides Quinone methide stabilization by metal complexation Self-immolative dendrimers based on quinone methides Characterization of quinone methides by spectral global fitting and 13C labeling Formation and reactions of xenobiotic quinone methides in biology Quinone methides in lignification With this collection of topics, readers already familiar with quinone methides have the opportunity to advance their own research by discovering new inspiration and opportunities in allied areas. Moreover, the range of topics and perspectives covered make this volume accessible to readers with a broad range of interests, including organic and physical chemistry, biochemistry, biotechnology, and pharmaceutics.