Download or read book Bacillus Subtilis Adenylosuccinate Lyase written by Jennifer Brosius Palenchar and published by . This book was released on 2003 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bacillus Subtilis and Human Adenylosuccinate Lyase written by Sharmila Sivendran and published by ProQuest. This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Adenylosuccinate lyase is a homotetrameric enzyme that catalyzes two reversible reactions in the purine biosynthetic pathway. ASL deficiency results from several single point mutations which result in mild to severe mental retardation, muscle wasting and autistic features. Two novel point mutations, E80D and D87E, identified in an Australian patient, were characterized. Although one of the point mutations, E80D, is far from the active site, it seems to have a more detrimental effect on enzyme function as compared to D69E, which is found close to the active site. Mutagenesis studies of conserved residues in the active site have suggested that p K 2 of the pH-V max profile reflects the ionization of histidines. Conserved residues close to His 68 in the crystal structure, Asp 69 and Arg 310, when analyzed by mutagenesis, show that replacement of these charged residues with neutral residues results in greatly decreased activity, suggesting these residues are important for catalytic activity. When the same charge is maintained there is little change in p K 2 (indicating the His 68 proton is held tightly, as in WT), but when the charge is removed there is a decrease in p K 2 suggesting the His 68 proton is removed more easily. This shift in p K 2 supports the previous postulate that His 68 acts as the general acid. ASL catalyzes two similar reactions, questioning whether the two substrates occupy the same or different active sites. Studies with a new substrate analogue, adenosine phosphonobutyric acid, 2'(3'), 5'-diphosphate, show the two substrates occupy the same active site. Binding studies with this substrate analogue demonstrate that B. subtilis ASL has negative and human ASL has positive cooperativity in binding ligand. Binding studies of B. subtilis ASL inactive mutants show that these mutants bind the substrate analogue similarly to WT, indicating the replaced amino acids are important for catalysis (k cat) and not for binding substrate. Serines in the signature sequence region of the fumarase superfamily of enzymes, when mutated to determine the effect of these residues on activity, show that human Ser 289, B. subtilis Ser 262 and Ser 263 affect V max but not binding and that they may be interacting with the active sites.
Download or read book Characterization of Bacillus Subtilis Adenylosuccinate Lyase and Its Association with Glutamyl tRNA Synthetase written by Jack F. Quinlan and published by . This book was released on 1998 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Implication of 2 Histidines in the Active Site of Bacillus Subtilis Adenylosuccinate Lyase by Affinity Labeling Mutagenesis and Molecular Modeling written by Tom T. Lee and published by . This book was released on 1998 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adenylosuccinate Lyases ASL from Bacillus Subtilis and Homo Sapiens written by Lushanti M. De Zoysa Ariyananda and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Adenylosuccinate lyase (ASL) belongs to the de novo purine biosynthesis pathway and the purine nucleotide cycle. It catalyses two reactions: conversion of SAICAR to AICAR and fumarate and conversion of adenylosuccinate to AMP and fumarate. ASL from all the species studied is a homotetramer in which three subunits contribute to each of four active sites. Human ASL deficiency is an inherited metabolic disease associated with autism and mental retardation. The majority of the missense mutations are compound heterozygous. In Chapter 2 we sought to evaluate the types of interactions responsible for subunit association of B. subtilis ASL. Perturbation of either hydrophobic or electrostatic interactions greatly destabilizes the tetramer of wild-type ASL and results in very low enzymatic activity. Accordingly, we mutated the closest charged residues located in the subunit interface that has the largest surface area. All the mutants have low V max values and decreased molecular weights. We conclude that both hydrophobic and electrostatic interactions play roles in maintaining the ASL tetramer and this structure is essential for adenylosuccinate lyase activity. Chapter 3 focuses on characterization of five disease-associated human ASL mutants located at different regions of the enzyme. Activity, stability of tetramer, and positive cooperativity of the mutant enzymes were reduced to different extents depending on the position in the enzyme. Thus, these disease-associated single mutations can yield enzyme with reduced activity either by affecting the active site or by perturbing the enzyme's structure and/or native conformation which are required for catalytic function. The possibility of forming hybrids in compound heterozygotes and separating the hybrids was assessed in Chapter 4. We were successful in forming various hybrids by denaturing the enzymes and renaturing by removing the denaturant, followed by separating the hybrids. There are favorable interactions between WT and mutant subunits, which accounts for the normal activity of ASL in the parents of ASL deficient patients, while the extent of interactions between two different mutant subunits depends upon the mutant enzymes. This implies that the presence of hybrids in parents of ASL deficient patients is highly advantageous, while it may not be true for severe ASL deficient patients.
Download or read book Index Medicus written by and published by . This book was released on 2004 with total page 2098 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vols. for 1963- include as pt. 2 of the Jan. issue: Medical subject headings.
Download or read book Purine and Pyrimidine Metabolism in Man IX written by Andrea Griesmacher and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 816 pages. Available in PDF, EPUB and Kindle. Book excerpt: th th This volume comprizes articles presented at the joint IX International and 6 Euro pean Symposium on Purine and Pyrimidine Metabolism in Man held in Gmunden, Austria, June 1 through 7, 1997. Since the first of this series of meetings was held in Israel in 1973, conventions were organized every three years in different parts of the world including the USA, Japan, and Europe. The different aspects of purine and pyrimidine metabolism bring together re searchers working in molecular genetics, biochemical pharmacology, biochemistry, devel opmental biology, immunology, epidemiology and the clinics. Oriented research in the field has been seminal for the development of potent anticancer and antiviral drugs. As the number of genes which are cloned, grows, the understanding of metabolism is increas ingly enlarged and might provide leads to further improve therapeutic concepts and to bet ter understand mechanisms responsible for the development of resistance against these drugs. In certain diseases purine and pyrimidine analogs represent not only the drugs of choice but in fact are the sole therapeutic alternative at present. The field has also taken an early lead in attempting to correct inborn errors of purine and pyrimidine metabolism by gene therapy. The organization of this meeting involved a large number of people who dedicated their time in an effort to make this symposium a success. We thank the Abstract Review Committee, the International Advisory Board and in particular the Symposium Secretariat for doing a wonderful job.
Download or read book Methods for studying the genetics molecular biology physiology and pathogenesis of the streptococci written by Paula M. Fives-Taylor and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is devoted entirely to methods developed in and for studies of members of the bacterial family Streptococcaceae. Many of the studies that have been conducted on the Streptococcaceae were initiated because of the diseases they cause, or to enhance their utility from an industrial perspective. However, the results of many of these investigations have demonstrated a complexity among some members of the family that warrants an interest in them in their own right, apart from or in addition to any biomedical or industrial considerations. It is therefore hoped and expected that the advanced methods contained in this book will be of interest to those who work with the streptococci and other Gram-positive organisms, to researchers interested in industrial and medical microbiology and to any researcher who seeks to obtain a better understanding of how microorganisms interact with each other, their environment and their hosts.
Download or read book Bacillus Subtilis written by Bunji Maruo and published by Elsevier Science & Technology. This book was released on 1989 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Industrial Enzymes written by Julio Polaina and published by Springer Science & Business Media. This book was released on 2007-05-16 with total page 629 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent developments in genetic engineering and protein chemistry are bringing ever more powerful means of analysis to bear on the study of enzyme structure. This volume reviews the most important types of industrial enzymes. In a balanced manner it covers three interrelated aspects of paramount importance for enzyme performance: three-dimensional protein structure, physicochemical and catalytic properties, and the range of both classical and novel applications.
Download or read book Cumulated Index Medicus written by and published by . This book was released on 2000 with total page 1836 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metabolic Pathways written by David Greenberg and published by Elsevier. This book was released on 2012-12-02 with total page 513 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metabolic Pathways, Third Edition: Volume IV: Nucleic Acids, Protein Synthesis, and Coenzymes focuses on the metabolic pathways of the major biological constituents of living organisms, namely, nucleic acids, proteins, and coenzymes. The biosynthesis and metabolism of purines and pyrimidines, nucleotides, riboflavin and related compounds, and vitamin B6 are discussed. The biogenesis and metabolism of thiamine and folic acid are also considered. This volume is comprised of seven chapters and begins with an analysis of metabolic control and enzymology of purines and pyrimidines such as inosinic acid and nucleotides. The next chapter is devoted to the biosynthesis and metabolism of nucleotides and nucleic acids, making reference to deoxyribonucleotides as well as RNA and DNA. Some of the reactions involving nucleotides are classified and briefly discussed. The reader is then introduced to protein synthesis, paying particular attention to the chemical features of the synthesis of the peptide bond and the characteristics of the genetic code implicated in this process. The remaining chapters focus on riboflavin and related compounds, thiamine, folic acid, and vitamin B6. This book will be a useful resource for biochemists and biologists.
Download or read book Class 1 Oxidoreductases III written by Dietmar Schomburg and published by Springer Science & Business Media. This book was released on 2004-03-23 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Springer Handbook of Enzymes provides concise data on some 5,000 enzymes sufficiently well characterized – and here is the second, updated edition. Their application in analytical, synthetic and biotechnology processes as well as in food industry, and for medicinal treatments is added. Data sheets are arranged in their EC-Number sequence. The new edition reflects considerable progress in enzymology: the total material has more than doubled, and the complete 2nd edition consists of 39 volumes plus Synonym Index. Starting in 2009, all newly classified enzymes are treated in Supplement Volumes.
Download or read book Bioprocess Engineering written by Shijie Liu and published by Elsevier. This book was released on 2020-04-07 with total page 960 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bioprocess Engineering: Kinetics, Sustainability, and Reactor Design, Third Edition, is a systematic and comprehensive textbook on bioprocess kinetics, molecular transformation, bioprocess systems, sustainability and reaction engineering. The book reviews the relevant fundamentals of chemical kinetics, batch and continuous reactors, biochemistry, microbiology, molecular biology, reaction engineering and bioprocess systems engineering, introducing key principles that enable bioprocess engineers to engage in the analysis, optimization, selection of cultivation methods, design and consistent control over molecular biological and chemical transformations. The quantitative treatment of bioprocesses is the central theme in this text, however more advanced techniques and applications are also covered. Includes biological molecules and chemical reaction basics, cell biology and genetic engineering Describes kinetics and catalysis at molecular and cellular levels, along with the principles of fermentation Covers advanced topics and treatise in interactive enzyme and molecular regulations, also covering solid catalysis Explores bioprocess kinetics, mass transfer effects, reactor analysis, control and design
Download or read book Genetics and Biotechnology of Bacilli Volume 2 written by A.T. Ganesan and published by Elsevier. This book was released on 2012-12-02 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: Genetics and Biotechnology of Bacilli, Volume 2 is a collection of papers from the "Fourth International Conference on Bacilli" held in California on June 21-24, 1987. One paper reviews the results of cloning and characterization of genes for secreted enzyme and of genes that control the expression of secreted enzymes in relation with other prokaryotic regulatory systems. Other papers tackle the regulation of gene expression during sporulation, the sigma factors, bacterial toxins, and antibiotic resistance genes. One paper reports that three genes responsible for the code for peptides found in BT cuboidal crystals have been successfully cloned. The three codes have different toxic characteristics in relation to tobacco hornworm larvae or mosquito larvae. Other papers examine replication. Such examination pertains to the two levels of control on the chromosome involved in DNA replication, or to the possible functional importance that several membranes associated DNA subcomplexes can have in Bacillus subtilis, where one of these appear to control initiation. Other papers discus secretion and extracellular enzymes, as well as, the different genetic systems and methods. This collection can prove beneficial for biochemists, micro-biologists, cellular researchers, and academicians involved in the study of cellular biology, microchemistry, or toxicology.
Download or read book Rapid Diagnosis of Mycoplasmas written by Itzahak Kahane and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: This compendium is the result of the FEMS Workshop on "Rapid Diagnosis of Mycoplasmas" which I organized and which took place in Jerusalem, Israel, August 11-23, 1991. The first week's sessions were held at a resort on the outskirts of Jerusalem and consisted of lectures and discussions. This part was modelled along the lines of the Gordon Conference in the USA, i.e., in an intimate atmo sphere in which everyone could mix and exchange ideas, and was very benefi cial. About 100 scientists from around the world attended the first week. Dur ing the first week, the biology, molecular biology and pathophysiology of myco plasmas, as well as all the main diagnostic methods were covered, including both conventional and the newer technologies. The session on mycoplasmas in the human urogenital tracts was held in conjunction with the Israel Society for the Study and Prevention of Sexually Transmitted Disease. The second week was a laboratory session and was held at the Hebrew University-Hadassah Medical School campus in Ein Karem, Jerusalem. All ex periments were conducted by eminent specialists in their field. The lab session had 36 participants from 19 countries who used the most modern techniques for the diagnosis of mycoplasmas in medicine, veterinary medicine and agri culture. The efficacy of several commercial kits were also tested at this time. I want to again thank everyone who helped and supported this work shop, as well as the authors of the various chapters.
Download or read book Class 4 Lyases III written by Dietmar Schomburg and published by Springer Science & Business Media. This book was released on 2001-11-20 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Springer Handbook of Enzymes provides concise data on some 5,000 enzymes sufficiently well characterized – and here is the second, updated edition. Their application in analytical, synthetic and biotechnology processes as well as in food industry, and for medicinal treatments is added. Data sheets are arranged in their EC-Number sequence. The new edition reflects considerable progress in enzymology: the total material has more than doubled, and the complete 2nd edition consists of 39 volumes plus Synonym Index. Starting in 2009, all newly classified enzymes are treated in Supplement Volumes.
