Download or read book Structure Function Relationship Studies of Escherichia Coli ADP glucose Pyrophosphorylase written by Clarisa Maria Bejar and published by . This book was released on 2006 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure Function Relationship of Plant ADP Glucose Pyrophosphorylase written by Ayşe Bengisu Seferoğlu and published by . This book was released on 2014 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure function Studies of a Novel ADP glucose Pyrophosphorylase from Thermotoga Maritima written by Shannon Lim and published by . This book was released on 2009 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Comparative Analysis of the Structure and Function Relationship of ADP glucose Pyrophosphorylases written by Jocelyn Reyes Frago and published by . This book was released on 2002 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure function Study on Allosteric Regulation of ADP glucose Pyrophosphorylase from Cyanobacterium Anabaena PCC 7120 written by Yee-Yung Charng and published by . This book was released on 1994 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure function Studies of a Novel ADP Glucose Pyrophosphorylase from Thermotoga Maritima written by Erick Guandique and published by . This book was released on 2011 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure Function Relationships of ADP Glucose Pyrophosphorylase and Branching Enzyme written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Conversion of the Potato tuber ADP-glucose Pyrophopshorylase Regulatory Subunit into a Catalytic Subunit. ADP-glucose synthesis, a rate-limiting reaction in starch synthesis, is catalyzed by ADP-glucose pyrophosphorylase (ADPGlc PPase). The enzyme in plants is allosterically activated by 3-phosphoglycerate (3PGA) and inhibited by inorganic phosphate [Pi] and is composed of two subunits as a heterotetramer, a2b2. Subunit a is the catalytic subunit and subunit b is designated as the regulatory subunit. The b subunit increases the affinty of the activator for the catalytic subunit. Recent results have shown that the subunits are derived from the same ancestor subunit as the regulatory subunit can be converted to a catalytically subunit via mutation of just two amino acids. Lys44 and Thr54 in the large subunit from potato tuber were converted to the homologous catalytic subunit residues, Arg33 and Lys43. The activity of the large subunit mutants cannot be readily tested with a co-expressed wild-type small (catalytic) subunit because of the intrinsic activity of the latter. We co-expressed the regulatory-subunit mutants with SmallD145N, an inactive S subunit in which the catalytic Asp145 was mutated. The activity of the small (catalytic) subunit was reduced more than three orders of magnitude. Coexpression of the L subunit double mutant LargeK44R/T54K with SmallD145N generated an enzyme with considerable activity, 10% and 18% of the wildtype enzyme, in the ADP-glucose synthetic and pyrophosphorolytic direction, respectively. Replacement of those two residues in the small subunit by the homologous amino acids in the L subunits (mutations R33K and K43T) decreased the activity one and two orders of magnitude. The wild-type enzyme and SmallD145NLargeK44R/T54K had very similar kinetic properties indicating that the substrate site has been conserved. The fact that only two mutations in the L subunit restored enzyme activity is very strong evidence that the large subunit is derived from the catalytic ancestor. Previous results showed that Asp145 in the small subunit of the wild-type is essential for catalysis, whereas the homologous Asp160 in the Large WT subunit is not. However, in this study, mutation D160N or D160E in the LK44R/T54K subunit abolished the activity, which shows the ancestral essential role of this residue and confirms that the catalysis of SmallD145NLarge K44R/T54K occurs in the L(b) subunit. A phylogenetic tree of the ADP-Glc PPases present in photosynthetic eukaryotes also sheds information about the origin of the subunits. The tree showed that plant Small and Large subunits can be divided into two and four distinct groups, respectively. The two main groups of S subunits are from dicot and monocot plants, whereas Large subunit groups correlate better with their documented tissue expression. The first Large-subunit group is generally expressed in photosynthetic tissues and comprises Large subunits from dicots and monocots. Group II displays a broader expression pattern, whereas groups III and IV are expressed in storage organs (roots, stems, tubers, seeds). Subunits from group III are only from dicot plants, whereas group IV are seed-specific subunits from monocots. These last two groups stem from the same branch of the phylogenetic tree and split before monocot and dicot separation. Thus few as two mutations turned the L subunit from Solanum tuberosum catalytic, showing that L and S subunits share a common catalytic ancestor, rather than a non-catalytic one. The L subunit evolved to have a regulatory role, lost catalytic residues more than 130 million years ago before monocots and dicots diverged, and preserved, possibly as a byproduct, the active site domain.
Download or read book Gene Conservation and Exploitation written by J. Perry Gustafson and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt: The potato (Solanum tuberosum L. ) tuber is a major food source in many countries of the world, and subsequently potato has been the target of a good deal of effort directed at engineering disease and herbicide tolerance, and improvements in various crop characteristics. Consequently investigations into the regulation of gene expression in tubers is relevant to these endeavours, as tubers are the main target organ for modification of gene expression. We have been interested in the regulation of genes in tubers for these reasons. Morphologically tubers are modified stems, which have enlarged radially by limited cell division and substantial expansion. At the molecular level, tuber development is characterised by a massive increase in starch deposition and the synthesis of a limited number of abundant proteins. These include proteinase inhibitors and a 40kd group of proteins called patatin, which are acyl hydrolases. Together these proteins account for over 50% of tuber proteins (reviewed by Bevan, 1991). The synthesis of these proteins has parallels to the synthesis of other somatic storage proteins, especially the VSP proteins of soybean. In both potato and soybean, removal of the sink for these proteins (tubers and pods, respectively) causes deposition in other tissues (Staswick, 1990). It is hypothesised that transcriptional control of the genes encoding these proteins is regulated in part by source-sink relationships of metabolites or other factors. In the case of VSPs, both amino acid levels and jasmonic acid play a major regulatory role (Staswick et aI.
Download or read book Structural Analysis of Branching Enzyme and ADP glucose Pyrophosphorylase written by Kim Binderup and published by . This book was released on 2000 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Starch in Food written by Malin Sjöö and published by Woodhead Publishing. This book was released on 2017-11-25 with total page 918 pages. Available in PDF, EPUB and Kindle. Book excerpt: Starch in Food: Structure, Function and Applications, Second Edition, reviews starch structure, functionality and the growing range of starch ingredients used to improve the nutritional and sensory quality of food. The new edition is fully updated and brings new chapters on starch and health, isolation, processing and functional properties of starch. Part One illustrates how plant starch can be analyzed and modified, with chapters on plant starch synthesis, starch bioengineering and starch-acting enzymes. Part Two examines the sources of starch, from wheat and potato, to rice, corn and tropical supplies. Part Three looks at starch as an ingredient and how it is used in the food industry, with chapters on modified starches and the stability of frozen foods, starch-lipid interactions and starch-based microencapsulation. Part Four covers starch as a functional food, investigating the impact of starch on physical and mental performance, detecting nutritional starch fractions and analyzing starch digestion. The book is a standard reference for those working in the food industry, especially to starch scientists, food researchers, post-docs, practitioners in the starch area and students. - Completely revised and updated with an overview of the latest developments in isolation, processing, functional properties and health attributes of starch - Reviews starch structure and functionality - Extensive coverage of the growing range of starch ingredients - Examines how starch ingredients are used to improve the nutritional and sensory quality of food
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2007 with total page 924 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Glucose 1 phosphate Binding Site and the Mechanism of Reductive Activation of Potato Tuber ADP glucose Pyrophosphorylase written by Yingbin Fu and published by . This book was released on 1998 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Research Awards Index written by and published by . This book was released on with total page 854 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Research Grants Index written by National Institutes of Health (U.S.). Division of Research Grants and published by . This book was released on 1969 with total page 862 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Diabetes Literature Index written by and published by . This book was released on 1979 with total page 1116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cumulated Index Medicus written by and published by . This book was released on 1966 with total page 1548 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seed Storage Compounds written by Peter R. Shewry and published by . This book was released on 1993 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seeds have long been harvested as a source of protein, oil, starch, and animal feed. This edited volume brings together authoritative writings on the three groups of seed storage compounds--proteins, lipids, and starch--and offers the most up-to-date account of their structure, biosynthesis, and modes of deposition available. The book also sheds light on compound interactions and on the mechanisms by which plants regulate the partitioning of carbon into lipid or starch. Finally, it discusses opportunities for the genetic engineering of plants either to manipulate the structures of the major seed storage compounds or to produce novel products. The book, which provides a synopsis of the field's exciting new developments not previously brought together in one easily accessible volume, will be of interest to students and researchers of plant physiology and biochemistry.
