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ADPGlucose Pyrophosphorylase (ADPG PPase) is an allosterically regulated enzyme that serves as the rate-limiting step of starch synthesis in plants and glycogen synthesis in bacteria. Because starc...

ADPGlucose pyrophosphorylase (ADPG PPase) catalyzes a key step in glucan biosynthesis. Structure-function studies of the enzyme will facilitate the engineering of a more active enzyme to increase b...

ADP-glucose pyrophosphorylase (ADPG PPase) is the rate limiting enzyme in the glucan biosynthesis pathway, a vital source for renewable and biodegradable carbon. Thus ADPG PPase is an attractive ta...

ADPGlucose Pyrophosphorylase (ADPG PPase) catalyzes the rate-limiting step of glucan biosynthesis in plants and bacteria. The successful engineering of ADPG PPase will allow for the production of more renewable and biodegradable carbon. Thermodesulfovibrio yellowstonii (Td.y) ADPG PPase shows only ~30% identity to other bacterial forms of the enzyme; at positions E15, F18, F23, S25, and S28 the Td.y enzyme differs from consensus in the glycine rich (positions 9-17) and KRAKPAV regions (positions 23-29), areas known to play roles in activity and allosteric regulation. These positions were targeted for mutagenesis and the enzymes purified using hydroxyapitite and DEAE chromatography. For wild-type (WT), kinetic studies revealed a Vmax of 5.3 U/mg and S0.5 values of 4.0 mM, 13.9 mM, and 1.2 mM for ATP, Mg, and G1P, respectively. Metabolites PEP, G6P, and 3PGA increased the Vmax by 1.5-3 fold and decreased the S0.5 values for ATP by 4.2, 10.3, and 3.8 fold, respectively. Initial kinetics for the variant S25A ...

A substantial number of plant genes have been identified and isolated recently, and methods for the rapid identification of other genes that are difficult to isolate using present techniques have been devised. Alterations to fundamental aspects of plant growth, and also to the structure and amount of storage products, are now possible. A wide variety of crop plants can now be transformed and a rapid increase in our knowledge of gene regulation in plants is taking place. The manipulation of plant genes for the benefit of argriculture now looks more promising than ever before.

ADPGlucose Pyrophosphorylase (ADPG PPase, glgC gene product) catalyzes a key step in glucan synthesis and is allosterically regulated. Engineering of the ADPG PPase from Rhodopseudomonas palustris ...