Focuses on particular aspects of the so-called Phase II of drug detoxication, which has important ramifications for endogenous metabolism and nutrition. This volume on glutathione transferases and gamma-glutamyl transpeptidases serves to bring together methods and concepts in a rapidly developing field of cell and systems biology.
The serene phrase, Lest I forget thee, glutathione ... , coined by the Kosowers (1) to describe the state in the 1960's, must be replaced now by something like "Inevitable GSH" in order to characterize the current situation. The surge in interest on the ubiquitous tripeptide has been ama zing, with publications on GSH running at rates as high as one per day, so that it seemed appropriate to convene international experts for a discussion of recent develop ments this year. Unlike the two previous meetings in this decade held in Tlibingen in 1973 (2) and in santa Ynez in 1975 (3), the scope was restricted to Functions of Gluta thione in Liver and Kidney. Only in this way did an in-depth discussion of the current state of knowledge in a limit ed topic appear possible. The last couple of years have seen a fascinating pro ductivity in the fields of (a) Regulation of the Glutathione Level in the Liver, (b) Role of y-Glutamyltransferase in Gluta thione Turnover with emphasis on the renal enzyme, and a critical appraisal of the y-Glutamyl Cycle, (c) Hyd:roperox ide and Disulfide Metaholism, enriched by the discovery of the nonseleniurn-dependent glutathione peroxidase activ ity and its relation to the glutathione-S-transferases, and the participation of the 2GSH/GSSG system in redox transitions in intact organ, cells and isolated mito chondria, and (d) a multitude of Pharmacological and Toxi cological Aspects related to glutathione, mainly centered on the events leading to liver damage and the protective
Gamma-Glutamyl Transpeptidases (γ-GTs) are members of the N-terminal nucleophile hydrolase superfamily, enzymes that cleave the γ-glutamyl amide bond of glutathione to liberate cysteinylglycine. The released γ-glutamyl group can be transferred to water (hydrolysis) or to amino acids or short peptides (transpeptidation). γ-GT plays a key role in the gamma glutamyl cycle by regulating the cellular levels of the antioxidant glutathione, hence it is a critical enzyme in maintaining cellular redox homeostasis.γ-GT is upregulated during inflammation and in several human tumors, and it is involved in many physiological disorders related to oxidative stress, such as Parkinson’s disease and diabetes. Furthermore, this enzyme is used as a marker of liver disease and cancer. This book covers current knowledge about the structure-function relationship of γ-GTs and gives information about applications of γ-GTs in different fields ranging from clinical biochemistry to biotechnology and biomedicine.
This book, combining and updating two previous editions, is a unique source of information on the diagnosis, treatment, and follow-up of metabolic diseases. The clinical and laboratory data characteristic of rare metabolic conditions can be bewildering for both clinicians and laboratory personnel. Reference laboratory data are scattered, and clinical descriptions may be obscure. The Physician’s Guide documents the features of more than five hundred conditions, grouped according to type of disorder, organ system affected (e.g. liver, kidney, etc) or phenotype (e.g. neurological, hepatic, etc). Relevant clinical findings are provided and pathological values for diagnostic metabolites highlighted. Guidance on appropriate biochemical genetic testing is provided. Established experimental therapeutic protocols are described, with recommendations on follow-up and monitoring. The authors are acknowledged experts, and the book will be a valuable desk reference for all who deal with inherited metabolic diseases.
A guide to the chemical agents that protect plants from various environmental stressors Protective Chemical Agents in the Amelioration of Plant Abiotic Stress offers a guide to the diverse chemical agents that have the potential to mitigate different forms of abiotic stresses in plants. Edited by two experts on the topic, the book explores the role of novel chemicals and shows how using such unique chemical agents can tackle the oxidative damages caused by environmental stresses. Exogenous application of different chemical agents or chemical priming of seeds presents opportunities for crop stress management. The use of chemical compounds as protective agents has been found to improve plant tolerance significantly in various crop and non-crop species against a range of different individually applied abiotic stresses by regulating the endogenous levels of the protective agents within plants. This important book: Explores the efficacy of various chemical agents to eliminate abiotic stress Offers a groundbreaking look at the topic and reviews the most recent advances in the field Includes information from noted authorities on the subject Promises to benefit agriculture under stress conditions at the ground level Written for researchers, academicians, and scientists, Protective Chemical Agents in the Amelioration of Plant Abiotic Stress details the wide range of protective chemical agents, their applications, and their intricate biochemical and molecular mechanism of action within the plant systems during adverse situations.
Glutathione (GSH) has been described for a long time just as a defensive reagent against the action of toxic xenobiotics (drugs, pollutants, carcinogens), both directly and as a cofactor for GSH transferases. As a prototype antioxidant, it has been involved in cell protection from the noxious effect of excess oxidant stress, both directly and as a cofactor of glutathione peroxidases. In addition, it has long been known that GSH is capable of forming disulfide bonds with cysteine residues of proteins, and the relevance of this mechanism ("S-glutathionylation") in regulation of protein function has been well documented in a number of research fields. Rather paradoxically, it has also been highlighted that GSH—and notably its catabolites, as originated by metabolism by gamma-glutamyltransferase—can promote oxidative processes, by participating in metal ion-mediated reactions eventually leading to formation of reactive oxygen species and free radicals. Also, a fundamental role of GSH has been recognized in the storage and transport of nitric oxide (NO), in the form of S-nitrosoglutathione (GSNO). The significance of GSH as a major factor in regulation of cell life, proliferation, and death, can be regarded as the integrated result of all these roles, as well as of more which are emerging in diverse fields of biology and pathophysiology. Against this background, modulation of GSH levels and GSH-related enzyme activities represents a fertile field for experimental pharmacology in numerous and diverse perspectives of animal, plant and microbiologic research. This research topic includes 14 articles, i.e. 4 Opinion Articles, 6 Reviews, and 4 Original Research Articles. The contributions by several distinguished research groups, each from his own standpoint of competence and expertise, provide a comprehensive and updated view over the diverse roles, the changing faces of GSH and GSH-related enzymes in cell’s health, disease and death.
Much of the information currently available on the transport systems of bacterial and animal cell membranes and their mode of coupling to metabolic supply of energy can be found in this volume. Consideration of the participating enzymes dictated the choice of topics: Several transport systems where little information is available on the enzymology of the process are not included, while separate chapters deal with y-glutamyl transpeptidase and intestinal disaccharidases which meet many of the requirements of transport enzymes. The volume also includes two chapters on photosynthetic membranes as a general introduction to the topic. Other aspects of biological transport and photosynthesis will be developed in detail in a forthcoming volume now in preparation. These chapters reveal the excitement and rapid advance of the field, the daily reports of new concepts, new techniques, and new experimental findings which instantly interact to generate further progress. Our aim was to provide a starting point for those who are just beginning, and an opportunity for others to stop, take stock, and start in a new direction. My warmest thanks to all who contributed to this volume.
The goal of this text is to focus readers attention on three major areas; the origin and localization of GSH in the nervous system; the multiple effects of GSH on neural health activity; and the potential for alterations on GSH status to lead to neurological damage of the type observed in amyotrophic lateral sclerosis, Parkinson's disease and other neurological disorders. The text also touches upon the additional roles of the antoxidant GSH, including possible neurotransmitter action, redox modulation of ionotropic receptor function, and neuroprotection against exicitoxic actions of glutamate.
This informative treatise offers a concise collection of existing, expert data summarizing the composition of milk. The Handbook of Milk Composition summarizes current information on all aspects of human and bovine milk, including: sampling, storage, composition, as well as specific chapters on major and minor components such as protein, carbohydrates, lipids, electrolytes, minerals, vitamins and hormones. The book also features comprehensive coverage of compartmentation, host-defense components, factors affecting composition, composition of commercial formulas, and contaminants.* Reliable data on the composition of human and bovine milks.* Discusses the many factors affecting composition.* Composition tables make up 25-30% of the total book.* Problems concerning sampling and analysis are described.* Should appeal equally to industry and academia.* Also of interest to developing countries in need of information on infant nutrition and agricultural development
Reduced glutathione (GSH) is the most important thiol in living organisms. It is the key component of antioxidant system and serves as a free radical scavenger. There is a cycle of GSH in biological systems and this cycle provides higher intracellular levels of GSH. GSH depletion and apparent oxidative stress may cause toxicity and can affect the general well-being of the organism. GSH was shown to be preventive against aging, cancer, heart disease, infections and dementia. This book is mainly focused on GSH in health and disease. The readers will gain qualified scientific knowledge on the diverse functions of GSH, the importance of GSH status against oxidative stress and the interaction between GSH and nervous system-related infections from this book.
