In-vitro rates of rumen proteolysis of ribulose-1,5-bisphosphate carboxylase (rubisco) from lucerne leaves, and of ovalbumin, vicilin and sunflower albumin 8 storage proteins

1994 ◽  
Vol 64 (1) ◽  
pp. 53-61 ◽  
Author(s):  
Warren C McNabb ◽  
Donald Spencer ◽  
Thomas J Higgins ◽  
Tom N Barry
Keyword(s):  
Storage Proteins ◽  
Bisphosphate Carboxylase ◽  
Sunflower Albumin

scholarly journals Design and in vitro realization of carbon-conserving photorespiration

2018 ◽  
Vol 115 (49) ◽  
pp. E11455-E11464 ◽  
Author(s):  
Devin L. Trudeau ◽  
Christian Edlich-Muth ◽  
Jan Zarzycki ◽  
Marieke Scheffen ◽  
Moshe Goldsmith ◽  
...  
Keyword(s):  
Carbon Fixation ◽  
Calvin Cycle ◽  
Computational Design ◽  
Carbon Loss ◽  
Fixation Rate ◽  
Bisphosphate Carboxylase ◽  
Stoichiometric Model ◽  
Synthetic Routes ◽  
Coa Reductase

Photorespiration recycles ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) oxygenation product, 2-phosphoglycolate, back into the Calvin Cycle. Natural photorespiration, however, limits agricultural productivity by dissipating energy and releasing CO2. Several photorespiration bypasses have been previously suggested but were limited to existing enzymes and pathways that release CO2. Here, we harness the power of enzyme and metabolic engineering to establish synthetic routes that bypass photorespiration without CO2 release. By defining specific reaction rules, we systematically identified promising routes that assimilate 2-phosphoglycolate into the Calvin Cycle without carbon loss. We further developed a kinetic–stoichiometric model that indicates that the identified synthetic shunts could potentially enhance carbon fixation rate across the physiological range of irradiation and CO2, even if most of their enzymes operate at a tenth of Rubisco’s maximal carboxylation activity. Glycolate reduction to glycolaldehyde is essential for several of the synthetic shunts but is not known to occur naturally. We, therefore, used computational design and directed evolution to establish this activity in two sequential reactions. An acetyl-CoA synthetase was engineered for higher stability and glycolyl-CoA synthesis. A propionyl-CoA reductase was engineered for higher selectivity for glycolyl-CoA and for use of NADPH over NAD+, thereby favoring reduction over oxidation. The engineered glycolate reduction module was then combined with downstream condensation and assimilation of glycolaldehyde to ribulose 1,5-bisphosphate, thus providing proof of principle for a carbon-conserving photorespiration pathway.

scholarly journals Characterization of the gene and mRNA of the large subunit of ribulose-1,5-bisphosphate carboxylase in pea plants.

1983 ◽  
Vol 3 (4) ◽  
pp. 587-595 ◽  
Author(s):  
K K Oishi ◽  
K K Tewari
Keyword(s):  
Immunoglobulin G ◽  
Large Subunit ◽  
Rrna Genes ◽  
Mapping Technique ◽  
Affinity Column ◽  
Bisphosphate Carboxylase ◽  
Bamhi Fragment ◽  
Dna Fragment

mRNA coding for the large subunit (LS) of ribulose-1,5-bisphosphate carboxylase was obtained by fractionating chloroplast polysomes on an affinity column, using anti-ribulose-1,5-bisphosphate carboxylase immunoglobulin G. Approximately 20% of the polysomal RNA specifically bound to the affinity column. LS mRNA was also isolated by fractionating chloroplast polysomal RNA on sucrose gradients. The LS mRNA fraction was identified by translation in vitro followed by immunoprecipitation with anti-ribulose-1,5-bisphosphate carboxylase immunoglobulin G. Labeled LS mRNA was hybridized to a genomic digests of pea chloroplast DNA. The LS gene was localized on a 3.55-kilobase pair BamHI fragment in SalI-SmaI DNA fragment 4. The BamHI fragment containing the LS gene was cloned, and a restriction endonuclease map was constructed. The LS gene was localized on a 1.9-kbp KpnI-EcoRI fragment. The LS gene was analyzed by electron microscopy, using the R loop mapping technique. LS mRNA was colinear with the gene, and its size was 1.35 +/- 0.2 kilobase pairs. When the LS mRNA was analyzed on methylmercury agarose gels, it comigrated with the 16S rRNA. The direction of transcription of the LS gene was in the same direction as that of the rRNA genes.

scholarly journals Effects of Cold Jet Atmospheric Pressure Plasma on the Structural Characteristics and Immunoreactivity of Celiac-Toxic Peptides and Wheat Storage Proteins

2020 ◽  
Vol 21 (3) ◽  
pp. 1012
Author(s):  
Fusheng Sun ◽  
Xiaoxue Xie ◽  
Yufan Zhang ◽  
Jiangwei Duan ◽  
Mingyu Ma ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Storage Proteins ◽  
Structural Characteristics ◽  
Atmospheric Pressure Plasma ◽  
High Energy ◽  
Backbone Cleavage ◽  
Excited Atoms ◽  
Wheat Storage Proteins ◽  
Toxic Peptides

The present research reported the effects of structural properties and immunoreactivity of celiac-toxic peptides and wheat storage proteins modified by cold jet atmospheric pressure (CJAP) plasma. It could generate numerous high-energy excited atoms, photons, electrons, and reactive oxygen and nitrogen species, including O3, H2O2, •OH, NO2− and NO3− etc., to modify two model peptides and wheat storage proteins. The Orbitrap HR-LC-MS/MS was utilized to identify and quantify CJAP plasma-modified model peptide products. Backbone cleavage of QQPFP and PQPQLPY at specific proline and glutamine residues, accompanied by hydroxylation at the aromatic ring of phenylalanine and tyrosine residues, contributed to the reduction and modification of celiac-toxic peptides. Apart from fragmentation, oxidation, and agglomeration states were evaluated, including carbonyl formation and the decline of γ-gliadin. The immunoreactivity of gliadin extract declined over time, demonstrating a significant decrease by 51.95% after 60 min of CJAP plasma treatment in vitro. The CJAP plasma could initiate depolymerization of gluten polymer, thereby reducing the amounts of large-sized polymers. In conclusion, CJAP plasma could be employed as a potential technique in the modification and reduction of celiac-toxic peptides and wheat storage proteins.

scholarly journals In Vitro Synthesis of the α and α′ Subunits of the 7S Storage Proteins (Conglycinin) of Soybean Seeds

1980 ◽  
Vol 65 (5) ◽  
pp. 990-994 ◽  
Author(s):  
Roger N. Beachy ◽  
Kenneth A. Barton ◽  
John F. Thompson ◽  
James T. Madison
Keyword(s):  
Storage Proteins ◽  
Soybean Seeds ◽  
In Vitro Synthesis ◽  
Α Subunits

Missing pieces in protein deposition and mobilization inside legume seed storage vacuoles: calcium and magnesium ions

2012 ◽  
Vol 22 (4) ◽  
pp. 249-258 ◽  
Author(s):  
Cláudia N. Santos ◽  
Marta M. Alves ◽  
Isabel T. Bento ◽  
Ricardo B. Ferreira
Keyword(s):  
Alkaline Earth ◽  
Storage Proteins ◽  
Lupinus Albus ◽  
Physiological Role ◽  
Experimental Conditions ◽  
Protein Storage Vacuoles ◽  
Aggregation And Disaggregation ◽  
Alkaline Earth Cations

AbstractDuring the maturation of dicotyledonous seeds, organic carbon, nitrogen and sulphur are stored in protein storage vacuoles (PSVs) as storage globulins. Several studies point to the coexistence of storage proteins with proteases responsible for their degradation inside PSVs. Different mechanisms have been proposed to explain why there is no proteolysis during this period. Protein aggregation to form large supramolecular structures resistant to proteolytic attack could be the reason. However, during germination, and particularly following its completion, the globulin aggregates must undergo disintegration to allow protease attack for protein reserve mobilization. Based on the well-described concentration-dependent ability of Ca2+ and Mg2+ to promote in vitro aggregation and disaggregation of globulins, we explored a possible role for these alkaline earth cations in globulin packaging and mobilization. Ca2+ and Mg2+ measurements in purified PSVs [6.37 μmol and 43.9 μmol g− 1 dry weight (DW) of cotyledons, respectively] showed the presence of these two alkaline earth cations within this compartment. To our knowledge, this is the first time that Ca2+ and Mg2+ have been quantified in purified PSVs from Lupinus albus seeds. Considering the importance of these two alkaline earth cations inside PSVs, which represent 14.6% and 60.7% of the total seed Mg2+and Ca2+, respectively, globulin aggregation and disaggregation profiles were assayed using experimental conditions closer to those that are physiologically present (proportion of Ca2+ and Mg2+, and acidic pH). Based on: (1) the high in vivo abundance of Ca2+ and Mg2+ inside PSVs; and (2) globulin aggregation and disaggregation profiles, together with structural and physiological evidence already reported in the literature, an important physiological role for Ca2+ and Mg2+ in globulin packaging and mobilization inside PSVs is suggested.

2-Carboxy-D-arabinitol 1-phosphate (CA1P) phosphatase: evidence for a wider role in plant Rubisco regulation

2012 ◽  
Vol 442 (3) ◽  
pp. 733-742 ◽  
Author(s):  
Paul John Andralojc ◽  
Pippa J. Madgwick ◽  
Yong Tao ◽  
Alfred Keys ◽  
Jane L. Ward ◽  
...  
Keyword(s):  
Protein Sequence ◽  
French Bean ◽  
Phosphoglycerate Mutase ◽  
Bisphosphate Carboxylase ◽  
Progressive Decline ◽  
Oxygenase Activity ◽  
Dtt Dithiothreitol ◽  
2,3 Dpg ◽  
Active Site Sequence

The genes for CA1Pase (2-carboxy-D-arabinitol-1-bisphosphate phosphatase) from French bean, wheat, Arabidopsis and tobacco were identified and cloned. The deduced protein sequence included an N-terminal motif identical with the PGM (phosphoglycerate mutase) active site sequence [LIVM]-x-R-H-G-[EQ]-x-x-[WN]. The corresponding gene from wheat coded for an enzyme with the properties published for CA1Pase. The expressed protein lacked PGM activity but rapidly dephosphorylated 2,3-DPG (2,3-diphosphoglycerate) to 2-phosphoglycerate. DTT (dithiothreitol) activation and GSSG inactivation of this enzyme was pH-sensitive, the greatest difference being apparent at pH 8. The presence of the expressed protein during in vitro measurement of Rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase) activity prevented a progressive decline in Rubisco turnover. This was due to the removal of an inhibitory bisphosphate that was present in the RuBP (ribulose-1,5-bisphosphate) preparation, and was found to be PDBP (D-glycero-2,3-pentodiulose-1,5-bisphosphate). The substrate specificity of the expressed protein indicates a role for CA1Pase in the removal of ‘misfire’ products of Rubisco.

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