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Search Results: 1 - 10 of 111878 matches for " Godson O. Osuji "
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Using the RNA synthetic activity of glutamate dehydrogenase to illuminate the natural role of the enzyme  [PDF]
Godson O. Osuji, Wenceslaus C. Madu
Advances in Biological Chemistry (ABC) , 2012, DOI: 10.4236/abc.2012.24047
Abstract: Glutamate Dehydrogenase (GDH; EC 1.4.1.2) catalyzes the reversible amination of α-ketoglutarate to glutamate, and the polymerization of nucleoside triphosphate(s) to RNA. But the natural role of the reversible amination reaction is the subject of an expanding conversation. The aim was to illuminate the natural role of GDH through its RNA synthetic activity. Stoichiometric combinations of mineral salts that targeted the GDH subunit compositions were applied to field-cultivated peanuts. GDH of seeds were made to synthesize RNA in the deamination and then in the amination direction. Free amino acids were analyzed by HPLC. Glutamate synthase (GOGAT) was assayed by photometry. Free amino acid yields in-creased from the control’s lowest (9.8 kg·ha–1) and amination-deamination ratio (0.05) through 12.0 - 23.0 kg·ha–1 in the K-, N+K+P+S-, Pi-, N+S-, S-treated peanuts with amination-deamination ratios between 0.6 and 10.0 until at the P+K-treated peanut which had the highest amino acid yield (52.4 kg·ha–1) and the highest amination-deamination ratio (61). The Km and Vmax values of GOGAT were within the normal range. Yields of free amino acids resulting from GDH aminating activity increased from <1.0 kg·ha–1 in the control, through 2.2 in the N+S-, 6.84 in the P+N-, 17.3 in the N-, to 42.6 kg·ha–1 in the P+K- treated peanut. These results show that the natural role of the GDH amination activity is to assimilate escalating multiples of the quantities of NH4+ ion as assimilated via the GS-GOGAT pathway. Peanut protein yields increased in parallel with GDH aminating activities and free amino acid yields such that the control peanut had the lowest protein (<26.0 kg·ha–1) and the yields increased exponentially (500 - 600 kg·ha–1) through the K-, P+S-, Pi-, N-treated to 910 kg·ha–1 in the P+K-treated peanut with the highest aminating activity of GDH. The ability of GDH aminating activity to escalate protein yields of food crops could be employed to address proteinenergy malnutrition syndrome of developing nations.
Structural Properties of the RNA Synthesized by Glutamate Dehydrogenase for the Degradation of Total RNA  [PDF]
Godson O. Osuji, Paul M. Johnson
Advances in Enzyme Research (AER) , 2018, DOI: 10.4236/aer.2018.63004
Abstract: Glutamate dehydrogenase (GDH)-synthesized RNA, a nongenetic code-based RNA is suitable for unraveling the structural constraints imposed on the regulation (transcription, translation, siRNA etc.) of metabolism by genetic code. GDH-synthesized RNAs have been induced in whole plants to knock out target mRNA populations thereby producing plant phenotypes that are allergen-free; enriched in fatty acids, essential amino acids, shikimic acid, resveratrol etc. Methods applied hereunder for investigating the structural properties of GDH-synthesized RNA included purification of GDH isoenzymes, synthesis of RNA by the isoenzymes, reverse transcription of the RNA to cDNA, sequencing of the cDNA, computation of the G+C-contents, profiling the stability through PCR amplification compared with genetic code-based DNA; and biochemical characterization of the RNAs synthesized by individual hexameric isoenzymes of GDH. Single product bands resulted from the PCR amplification of the cDNAs of GDH-synthesized RNA, whereas several bands resulted from the amplification of genetic code-based DNA. The cDNAs have wide G+C-contents (35% to 59%), whereas genetic code-based DNA has narrower G+C-contents (50% to 60%). The GDH β6 homo-hexameric isoenzyme synthesized the A+U-rich RNAs, whereas the a6, and α6 homo-hexameric isoenzymes synthesized the G+C-rich RNAs. Therefore, the RNA synthesized by GDH is different from genetic code-based RNAs. In vitro chemical reactions revealed that GDH-synthesized RNA degraded total RNA to lower molecular weight products. Therefore, GDH-synthesized RNA is RNA enzyme. Dismantling of the structural constraints imposed on RNA by genetic code liberated RNA to become an enzyme with specificity to degrade unwanted transcripts. The RNA enzyme activity of GDH-synthesized RNA is ubiquitous in cells; it is readily induced by treatment of plants with mineral nutrients etc. and may simplify experimental approaches in plant enzymology and molecular biology research projects.
Responses of bioenergy sorghum cell wall metabolism to agronomic practices  [PDF]
Jason P. Wight, Frank M. Hons, Godson O. Osuji
Advances in Biological Chemistry (ABC) , 2014, DOI: 10.4236/abc.2014.41010
Abstract:

Maximum lignocellulose yield of biomass sorghum [Sorghum bicolor L. (Moench.)] is hampered by complex biological phenomena related to rotation, nitrogen (N) fertilization, soil tillage, and excessive biomass removal. The biochemical basis of the effects of agronomic practices on sorghum production was studied by the enzymology of the active peroxidase (EC 1.11.1.7) isoenzymes that synthesize lignin. All studied practices altered the peroxidase pI values. Control sorghum without rotation and without N fertilization had the most inhibited peroxidase with very low maximum velocity (Vmax) value (3.10 mmol·min﹣1), and very low lignin (857 kg·ha﹣1) yield, which could decrease soil organic carbon possibly leading to adverse changes in soil chemistry. Corn-sorghum rotations with and without N fertilization increased the Vmax values of peroxidase and lignin and cellulose yields. Rotated sorghum subjected to 50% residue return (the percentage of crop residue was returned to the plot immediately after grinding at harvest) and 280 kg·ha﹣1 N fertilization possessed very active peroxidase (Vmax value 66.4 mmole·min﹣1) and the highest lignin (1387 kg·ha﹣1) yield. The 25% residue return rate without N fertilization induced high lignin (1125 kg·ha﹣1) and cellulose (11,961 kg·ha﹣1) but the 25% residue return rate with 280 kg·ha﹣1 N fertilization induced lower lignin (1046 kg·ha﹣1) yield. Continuously cropped sorghum treated with 336 kg·N·ha﹣1 produced active peroxidase that shared competitive inhibition relationship with the peroxidase of the 84 kg·N·ha﹣1 treatment. Ridge tillage combined with 280 kg·ha﹣1 N fertilization under continuous sorghum resulted in inhibited peroxidase possessing low Vmax value (13.0 μmole·min﹣1). Changing to conventional tillage combined with 280 kg·ha﹣1 N fertilization relieved the inhibition and increased the Vmax value to 23.7 mmol·min﹣1. These biological anomalies of sorghum cell wall related to agronomic practices originated from doubly inhibited sorghum peroxidases. This understanding may guide the choice of sustainable agronomic practices for maximizing lignocellulose yields for the bioenergy industry while protecting the environment.

Doubling of crop yield through permutation of metabolic pathways  [PDF]
Godson O. Osuji, Tassin K. Brown, Sanique M. South, Justin C. Duncan, Dwiesha Johnson
Advances in Bioscience and Biotechnology (ABB) , 2011, DOI: 10.4236/abb.2011.25054
Abstract: Hunger and food insecurity can be minimized by doubling crop yield without increasing cultivated land area and fertilizer applied. Since plant breeding has not genetically doubled photosynthesis per unit leaf area, an approach for doubling crop yield would be through a biotechnology that reprograms metabolic pathways in favor of photosynthesis. The anchor of this biotechnology is glutamate dehydrogenase (GDH) including the RNAs it synthesizes. Peanut was treated with stoichiometric combinations of mineral salt solutions to synchronize the GDH subunit polypeptides. Matured seeds were analyzed for fats by HPLC; the RNA biosynthetic activity of GDH, and mRNAs encoding yield-specific enzymes by Northern hybridization. In the PK-treated peanut, the GDH-synthesized RNAs silenced the mRNAs encoding granule-bound starch synthase, phosphoglucomutase (glycolysis), glucosyltransferase (cellulose biosynthesis), and nitrate reductase leaving unaffected the mRNAs encoding acetylcoenzyme A carboxylase (fatty acid biosynthesis), phosphate translocator, and NADH-glutamate synthase resulting to double seed (4342 kg/ha), cellulose (1829 kg/ha), and fat (1381 kg/ha) yields compared with the controls. Down-regulation of phosphate translocator and acetylcoenzyme A carboxylase caused decreased pod yields. GDH-synthesized RNAs that were homologous to yield-specific mRNAs shared extensive plus/plus and plus/minus sequence similarities, and they reprogrammed metabolism by permuting the partially down-regulated, not down-regulated, and down-regulated yield-specific pathways. Control peanut produced 70, NPKS-treated produced 420, NS-treated produced 1680, and PK-treated produced 280 probable rearrangements of the pathways. Therefore, down-regulation of metabolic reactions followed by permutation of yield-related pathways, and redistribution of metabolite load to molecularly connected pathways controls crop yield. Operating as efficient bioreactor, peanut can be maximized to 10000 kg pod/ha, more than enough vegetable oil for nine billion people.
Molecular Adaptation of Peanut Metabolic Pathways to Wide Variations of Mineral Ion Composition and Concentration  [PDF]
Godson O. Osuji, Tassine K. Brown, Sanique M. South, Justin C. Duncan, Dwiesha Johnson, Shanique Hyllam
American Journal of Plant Sciences (AJPS) , 2012, DOI: 10.4236/ajps.2012.31003
Abstract: Plant evolution, nutritional genomics, and mineral nutrition have been well documented but no studies have focused on the molecular adaptation of crop metabolism to wide variations of mineral ion composition and concentration. Diversification of peanut species from primary centers of domestication in South America depended on metabolic adaptation to the mineral ion conditions of the newer habitats. Understanding the diversification molecular biology of peanut metabolic pathways will permit the synthesis of the best mineral ion combinations for doubling CO2 assimilation. Valencia and Virginia cultivars belong to different subspecies of the tetraploid Arachis hypogaea. They were planted in the absence and presence of up to 99 mM (equivalent to 166 moles per hectare) of different mineral ions. Molecular properties of the primary metabolic pathways were studied by Northern analyses using Valencia GDH-synthesized RNAs as probes for Virginia mRNA and GDH-synthesized RNAs. Messenger RNAs are silenced by homologous RNAs synthesized by GDH. Peanut cellulose was analyzed by gravimetry; and fatty acids by HPLC. Complementary DNA probes made from Valencia GDH-synthesized RNAs hybridized perfectly to Virginia mRNAs and GDH-synthesized RNAs. Wide variations in mineral ion compositions and concentrations induced the GDHs of Valencia and Virginia to synthesize RNAs that differentially down-regulated the mRNAs encoding phosphate translocator, granule-bound starch synthase, phosphoglucomutase, glucosyltransferase, acetyl CoA carboxylase, nitrate reductase, and NADH-glutamate synthase so that the percent weights of oil (41.53 ± 8.75) and cellulose (30.29 ± 3.12) were similar in the control and mineral-treated peanuts. Therefore, RNA sequences that defined the molecular adaptation of mRNAs encoding the enzymes of primary metabolism were the same in the varietal types of A. hypogaea, in agreement with genetic data suggesting that tetraploid Arachis evolved relatively recently from the wild diploid ancestral species. Another molecular adaptation was to phosphate with or without K+ ion, and it prevented the silencing by GDH-synthesized RNAs of the mRNA encoding phosphate translocator resulting to doubling of cellulosic biomass yield (41323 kg/ha) compared with the N + P + K + S-treated positive control peanut (19428 kg/ha). Molecular adaptation of primary metabolic pathways at the mRNA level to SO42- ion with or without SO42- ion did not increase cellulosic biomass yields (27057 kg/ha) compared with negative control
Purification of Active Peroxidase Isoenzymes and Their Responses to Nitrogen Fertilization and Rotation of Biomass Sorghum  [PDF]
Jason P. Wight, Frank M. Hons, Sanique M. South, Godson O. Osuji
American Journal of Plant Sciences (AJPS) , 2012, DOI: 10.4236/ajps.2012.310172
Abstract: Peroxidases (EC 1.11.1.7) participate in lignin biosynthesis. But peroxidation is not a tool for assaying lignocellulose metabolism because the active cannot yet be separated from the inactive peroxidases. A biochemical tool for assaying plant cell wall responses to agronomic practices is needed in the lignocellulosic feedstock renewable energy industry. Peroxidase of biomass sorghum was purified to 9 - 13 charge isomers by free solution IEF (Rotofor) technique. Free solution IEF was more effective than chromatographic purification of active peroxidase isoenzymes. Native PAGE separated each charge isomer to three anionic and three cationic isoenzymes. Hydrogen peroxide and o-dianisidine assays showed that only 20% - 30% of the isoenzymes displayed normal Michaelis-Menten kinetics. Sorghum planted without nitrogen fertilization induced the hydrogen peroxide noncompetitive inhibition of peroxidase, but 280 kg·ha–1 nitrogen fertilization and 100% sorghum mineral residue return to the soil tripled the concentration of active peroxidase and relieved the inhibition with concomitant increases of 350 kg lignin and 3532 kg·cellulose·ha–1. Nitrogen fertilization without crop rotation induced hydrogen peroxide inhibition of the peroxidase, but nitrogen fertilization and 25% sorghum rotation changed the PI of the active peroxidase from neutral to mildly acidic and relieved the inhibition with concomitant enormous increases of 690 kg lignin and 7151 kg·cellulose·ha–1. Hydrogen peroxide inhibition kinetics is consistent with the known peroxidase-substrate intermediate dead-end complex formation. Lignocellulosic yield was greatest under the agronomic management that combined 280 kg·ha–1 nitrogen fertilizer with 25% sorghum residue, which resulted in a shift of pI value of the active peroxidase due to a reduction in the Km value of the peroxidase. Therefore, up to 75% of sorghum biomass rather than only 50% can be harvested for conversion to bioenergy products.
Horticultural Production of Ultra High Resveratrol Peanut  [PDF]
Godson O. Osuji, Paul Johnson, Eustace Duffus, Sela Woldesenbet, Jeneanne M. Kirven
Agricultural Sciences (AS) , 2017, DOI: 10.4236/as.2017.810086
Abstract:
Background: Resveratrol naturally occurring antioxidant in peanut (Legume: Arachis hypogaea) has phytochemical human health dietary effects associated with reduced inflammatory cancer risks. Its levels in peanut are ultra-low and variable (0 to 26 μg·g-1), which has made it difficult to market as a consistent high resveratrol produce. Objective: Understanding the regulation of resveratrol accumulation in peanut might lead to development of new techniques for optimizing and stabilizing its yield. Method: Peanuts were cultivated in horticultural field plots and treated with solutions of mineral salts (sulfate, potassium, phosphate, ammonium ion) that were optimized in stoichiometric (reactive) ratios. Peanut seed’s RNAs were subjected to Northern blot analysis for profiling the RNAs synthesized by glutamate dehydrogenase (GDH), and mRNAs encoding resveratrol synthase. The seed’s extracts were analyzed by GC-MS for determination of the resveratrol and fatty acid compositions. Result: Stoichiometric mixes of mineral ions induced the peanut GDH to synthesize some RNA that silenced the mRNAs encoding resveratrol synthase, phosphoglucomutase, isocitrate lyase, malate synthase, enolase, phosphoenolpyruvate carboxylase, malate dehydrogenase, and phosphoglycerate mutase in the control, KN-, and NPKS-treated but not in the NPPK-treated peanut. These resulted to decreased resveratrol content (6.0 μg·g-1) in the control peanut but maximized it (1.15 mg·g-1) in the NPPK-treated peanut. Therefore, resveratrol accumulation was optimized by coupling of glycolysis and citric-glyoxylic acid cycles to resveratrol biosynthesis. Fatty acid content of control (55.6 g·kg-1) was higher than the NPKS-treated (48.5 g·kg-1) and NPPK-treated peanut (44.9 g·kg-1) meaning that malonyl-CoA intermediate in both fatty acid and stilbenoid pathways was diverted to support maximum resveratrol biosynthesis in the NPPK-treated peanut. Conclusion: The functional coupling of citric-glyoxylic acid cycles and glycolysis to optimize resveratrol biosynthesis may encourage development of horticultural technology specific for production of ultra-high resveratrol peanuts.
Terpene-Rich Medicinal Plant Spices for Flavoring of Processed Tropical Food  [PDF]
Appolonia A. Obiloma, Wenceslaus C. Madu, Godson O. Osuji, Peter A. Ampim, Aruna D. Weerasooriya, Laura E. Carson
American Journal of Plant Sciences (AJPS) , 2019, DOI: 10.4236/ajps.2019.104041
Abstract: Tropical medicinal plant spices have remained underutilized in commercial food processing because of the inadequate chemical characterization of their terpene compositions. The activity of medicinal plants used in flavoring is due to their terpene contents. Terpene contents of Aframomum danielli seeds, Xylopia aethiopica fruits, Syzygium aromaticum leaves, Piper guineense seeds, and Monodora myristica seeds were determined using headspace solid-phase microextraction combined with gas chromatography-mass spectrometry. P. guineense is rich in terpinene and terpinolene (2.5 g per 100 g), S. aromaticum has caryophyllene (0.68 g per 100 g); A. danielli is rich in ocimene (1.65 g per 100 g); X. aethiopica is rich in ocimene (2.94 g per 100 g); M. mystristica is rich in delta carene (0.49 g per 100 g). Combinations of the five medicinal plant spices are being applied as flavorings in packaged tropical food.
Total RNA Degradation in Vitro and in Vivo by Glutamate Dehydrogenase-Synthesized RNA Enzyme: Biotechnological Applications  [PDF]
Godson O. Osuji, Wenceslaus C. Madu, Paul M. Johnson
Advances in Bioscience and Biotechnology (ABB) , 2019, DOI: 10.4236/abb.2019.104005
Abstract: Glutamate dehydrogenase regulates crop development, growth, and biomass yield through its synthesis of non-genetic code-based RNA. Understanding the mechanism of GDH-synthesized RNA enzyme would enhance the agriculture innovation capacity of the more than a billion urban gardeners, smallholder, and limited resources indigenous farmers. Different metabolic variants were prepared by treating peanut growing on healthy soil with stoichiometric mixes of mineral salt solutions. Peanut GDH charge isomers were purified to homogeneity by electrophoresis, and made to synthesize RNA enzyme. Peanut total RNA was 5’-end labeled with [γ-32P]ATP and made to react as substrate in vitro with GDH-synthesized RNA from another metabolic variant of peanut. Agarose, and polyacrylamide gel electrophoresis of the reaction products showed that tRNA, rRNA, and most of the mRNAs were degraded to mononucleotides, but total RNAs that were not mixed with GDH-synthesized RNAs were not degraded. When the non-homologous sequence sections of the GDH-synthesized RNA were clipped out, the homologous sections failed to produce Northern bands with peanut total RNA. Therefore, the non-homologous sequence sections served to identify, position, and align the GDH-synthesized RNA to its target total RNA site independent of genetic code; the degradation of total RNA being via non-canonical base alignments in the enzyme-substrate complex, followed by electromagnetic destruction of the total RNA, the less stable of the two kinds of RNA. This is the science-based corner stone that buttresses the crop production efforts of limited resources farmers because GDH-synthesized RNAs quickly degrade superfluous total RNA of the crop in response to the soil mineral nutrient deficiencies thereby minimizing wastage of metabolic energy in the synthesis of unnecessary protein enzymes while optimizing biomass metabolism, crop growth, and maximum crop yields. In vitro hydrolysis of
Molecular Regulation of the Metabolic Pathways of the Medicinal Plants: Phyla dulcis  [PDF]
Godson O. Osuji, Aruna Weerasooriya, Peter A. Y. Ampim, Laura Carson, Paul Johnson, Yoonsung Jung, Eustace Duffus, Sela Woldesenbet, Sanique South, Edna Idan, Dewisha Johnson, Diadrian Clarke, Billy Lawton, Alfred Parks, Ali Fares, Alton Johnson
American Journal of Plant Sciences (AJPS) , 2015, DOI: 10.4236/ajps.2015.611171
Abstract: Phyla (Lippia) dulcis contains hernundulcin sesquiterpene zero-caloric sweetener that is about a thousand times sweeter than sucrose, and also bitter constituents including camphor and limonene. There is yet no simple method to remove the undesirable constituents. The yield of sweetener hernundulcin is very low, and there is no simple method to maximize its composition. The aim of the project was to characterize the mRNA targets that regulate the primary and terpenoid metabolic enzymes of P. dulcis. Restriction fragment differential display polymerase chain reaction of P. dulcis glutamate dehydrogenase-synthesized RNA showed that many mRNAs encoding β-caryophyllene, (+)-epi-α-bisabolol, bicyclogermacrene, bifunctional sesquiterpene, and geraniol synthases shared sequence homologies with ribulose-1,5-bisphophatase carboxylase, granule-bound starch synthase, pyruvate kinase, glucose-6-phosphate dehydrogenase, and phosphoenol pyruvate carboxylase. Sequence similarities between mRNAs encoding primary metabolic enzymes and terpene synthases suggested that photosynthesis could regulate terpenoid metabolism in order to increase the yield of sweetener hernundulcin.
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