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1.
Nat Biotechnol ; 39(8): 989-999, 2021 08.
Article in English | MEDLINE | ID: mdl-33859400

ABSTRACT

Plasma-derived polyclonal antibody therapeutics, such as intravenous immunoglobulin, have multiple drawbacks, including low potency, impurities, insufficient supply and batch-to-batch variation. Here we describe a microfluidics and molecular genomics strategy for capturing diverse mammalian antibody repertoires to create recombinant multivalent hyperimmune globulins. Our method generates of diverse mixtures of thousands of recombinant antibodies, enriched for specificity and activity against therapeutic targets. Each hyperimmune globulin product comprised thousands to tens of thousands of antibodies derived from convalescent or vaccinated human donors or from immunized mice. Using this approach, we generated hyperimmune globulins with potent neutralizing activity against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in under 3 months, Fc-engineered hyperimmune globulins specific for Zika virus that lacked antibody-dependent enhancement of disease, and hyperimmune globulins specific for lung pathogens present in patients with primary immune deficiency. To address the limitations of rabbit-derived anti-thymocyte globulin, we generated a recombinant human version and demonstrated its efficacy in mice against graft-versus-host disease.


Subject(s)
B-Lymphocytes/immunology , COVID-19/therapy , Globulins/biosynthesis , SARS-CoV-2/immunology , Animals , Antibodies, Viral/immunology , CHO Cells , Cricetulus , Enzyme-Linked Immunosorbent Assay , Globulins/immunology , Humans , Immunization, Passive , Mice , Recombinant Proteins/biosynthesis , Recombinant Proteins/immunology , Zika Virus/immunology , COVID-19 Serotherapy
2.
Trop Anim Health Prod ; 50(8): 1739-1746, 2018 Dec.
Article in English | MEDLINE | ID: mdl-29748846

ABSTRACT

This study determined the effects of feed supplementation during the postpartum period on the weight gain, milk yield, blood profiles and reproductive performance of Sanga and Friesian-Sanga cows grazing on natural pasture. 20 Sanga and 20 Friesian-Sanga cows were randomly allocated either to serve as a control on grazing only or to be supplemented with 2.5 kg of concentrate a day for 10 weeks during the dry season. Each week, all cows were weighed and scored for body condition. Partial milk yield of cows was determined daily. Plasma concentrations of blood metabolites were assessed fortnightly from weeks 1 to 10 postpartum. Resumption of postpartum ovarian activity was determined by measuring progesterone concentration in the plasma from weeks 1 to 10. Supplemented cows had a better body condition score (6.2 versus 5.8; P < 0.05) and higher partial milk yield (1.94 versus 1.55 L/day; P < 0.01) than non-supplemented cows. Sanga cows had a better body condition score (6.2 versus 5.8; P < 0.05) but lower milk yield (1.58 versus 1.92 L/day; P < 0.01) than the Friesian-Sanga crossbreds. Total protein (P < 0.05) and albumin (P < 0.01) concentrations were higher in the supplemented than in the non-supplemented cows. Sanga cows recorded higher globulin (P < 0.05) and total cholesterol (P < 0.01) but lower albumin (P < 0.01) concentrations than Friesian-Sanga crossbred cows. Feed supplementation did not affect (P < 0.05) the interval from calving to resumption of ovarian activity, and the days to resumption of ovarian activity in the Sanga and Friesian-Sanga cows were also similar (P > 0.05). The results demonstrate the beneficial effects of feed supplementation in terms of improved body condition and metabolic status and increased milk yield.


Subject(s)
Animal Feed , Cattle/physiology , Dietary Supplements , Milk , Albumins/biosynthesis , Animal Husbandry , Animals , Cattle/growth & development , Cholesterol/blood , Female , Globulins/biosynthesis , Lactation , Poaceae , Postpartum Period , Progesterone/blood , Random Allocation , Reproduction , Seasons , Weight Gain
3.
Pak J Pharm Sci ; 29(5): 1555-1563, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27731812

ABSTRACT

Doxorubicin and Cyclophosphamide (AC protocol) combination is usually considered as a first line therapy in newly diagnosed breast cancer patients. Thus, a retrospective observational study was conducted to monitor the effect of AC protocol on liver synthetic functions and production of plasma proteins in breast cancer patients, reporting to specialized cancer care hospital of Lahore, Pakistan. A total of 75 patients (n=75) on AC protocol with breast cancer were observed in this study. The patient data including age, gender, body surface area, dosage, disease status and laboratory biochemical values were recorded by reviewing historical treatment records. Pre-treatment values were taken as baseline values for albumin, globulin, blood urea nitrogen (BUN), albumin/globulin (A/G) ratio and total proteins. The baseline values were compared after each cycle of by applying ANOVA using statistical tool SPSS® version 21. The plasma levels of blood urea nitrogen (BUN), total protein and globulin dropped significantly (p<0.05) in patients of all age groups. However, the albumin levels were not significantly changed (p>0.05). The A/G ratio level increased (p<0.05) as a result of reduction in globulin levels. Significant changes in plasma protein levels were observed in the elderly patients (50 to 65 years) than patients between 20 to 50 years of age. AC protocol impairs liver synthetic functions as observed by decreased blood urea nitrogen (BUN) and plasma protein levels.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/adverse effects , Blood Proteins/biosynthesis , Breast Neoplasms/drug therapy , Chemical and Drug Induced Liver Injury/etiology , Cyclophosphamide/adverse effects , Doxorubicin/adverse effects , Liver/drug effects , Adult , Age Factors , Aged , Biomarkers/blood , Blood Urea Nitrogen , Breast Neoplasms/diagnosis , Chemical and Drug Induced Liver Injury/blood , Chemical and Drug Induced Liver Injury/diagnosis , Cyclophosphamide/administration & dosage , Doxorubicin/administration & dosage , Female , Globulins/biosynthesis , Humans , Liver/metabolism , Middle Aged , Pakistan , Retrospective Studies , Serum Albumin/biosynthesis , Serum Albumin, Human , Time Factors , Treatment Outcome , Young Adult
4.
Int J Mol Sci ; 16(7): 14717-36, 2015 Jun 30.
Article in English | MEDLINE | ID: mdl-26133242

ABSTRACT

The major seed storage proteins (SSPs) in rice seeds have been classified into three types, glutelins, prolamins, and globulin, and the proportion of each SSP varies. It has been shown in rice mutants that when either glutelins or prolamins are defective, the expression of another type of SSP is promoted to counterbalance the deficit. However, we observed reduced abundances of glutelins and prolamins in dry seeds of a globulin-deficient rice mutant (Glb-RNAi), which was generated with RNA interference (RNAi)-induced suppression of globulin expression. The expression of the prolamin and glutelin subfamily genes was reduced in the immature seeds of Glb-RNAi lines compared with those in wild type. A proteomic analysis of Glb-RNAi seeds showed that the reductions in glutelin and prolamin were conserved at the protein level. The decreased pattern in glutelin was also significant in the presence of a reductant, suggesting that the polymerization of the glutelin proteins via intramolecular disulfide bonds could be interrupted in Glb-RNAi seeds. We also observed aberrant and loosely packed structures in the storage organelles of Glb-RNAi seeds, which may be attributable to the reductions in SSPs. In this study, we evaluated the role of rice globulin in seed development, showing that a deficiency in globulin could comprehensively reduce the expression of other SSPs.


Subject(s)
Globulins/biosynthesis , Glutens/metabolism , Oryza/metabolism , Seeds/metabolism , Glutens/genetics , Oryza/growth & development , Seeds/growth & development
5.
Nat Commun ; 5: 4847, 2014 Sep 11.
Article in English | MEDLINE | ID: mdl-25209128

ABSTRACT

Grains from cereals contribute an important source of protein to human food, and grain protein content (GPC) is an important determinant of nutritional quality in cereals. Here we show that the quantitative trait locus (QTL) qPC1 in rice controls GPC by regulating the synthesis and accumulation of glutelins, prolamins, globulins, albumins and starch. qPC1 encodes a putative amino acid transporter OsAAP6, which functions as a positive regulator of GPC in rice, such that higher expression of OsAAP6 is correlated with higher GPC. OsAAP6 greatly enhances root absorption of a range of amino acids and has effects on the distribution of various amino acids. Two common variations in the potential cis-regulatory elements of the OsAAP6 5'-untranslated region seem to be associated with GPC diversity mainly in indica cultivars. Our results represent the first step toward unravelling the mechanism of regulation underlying natural variation of GPC in rice.


Subject(s)
Amino Acid Transport Systems/genetics , Oryza/genetics , Plant Proteins/genetics , Albumins/biosynthesis , Albumins/metabolism , Amino Acids/metabolism , Base Sequence , Globulins/biosynthesis , Globulins/metabolism , Glutens/biosynthesis , Glutens/metabolism , Molecular Sequence Data , Oryza/metabolism , Plant Roots/metabolism , Prolamins/biosynthesis , Prolamins/metabolism , Quantitative Trait Loci , Starch/biosynthesis , Starch/metabolism
6.
J Biosci Bioeng ; 118(4): 441-7, 2014 Oct.
Article in English | MEDLINE | ID: mdl-24794626

ABSTRACT

There has been a significant increase in the use of transgenic plants for the large-scale production of pharmaceuticals and industrial proteins. Here, we report the stable accumulation of seed storage proteins containing disease vaccine peptides in transgenic soybean seeds. To synthesize vaccine peptides in soybean seeds, we used seed storage proteins as a carrier and a soybean breeding line lacking major seed storage proteins as a host. Vaccine peptides were inserted into the flexible disordered regions in the A1aB1b subunit three-dimensional structure. The A1aB1b subunit containing vaccine peptides in the disordered regions were sorted to the protein storage vacuoles where vaccine peptides are partially cleaved by proteases. In contrast, the endoplasmic reticulum (ER)-retention type of the A1aB1b subunit containing vaccine peptides accumulated in compartments that originated from the ER as an intact pro-form. These results indicate that the ER may be an organelle suitable for the stable accumulation of bioactive peptides using seed storage proteins as carriers.


Subject(s)
Alzheimer Vaccines/biosynthesis , Globulins/biosynthesis , Glycine max/genetics , Peptides/immunology , Seeds/genetics , Soybean Proteins/biosynthesis , Alzheimer Disease/immunology , Alzheimer Disease/prevention & control , Alzheimer Vaccines/genetics , Alzheimer Vaccines/immunology , Amino Acid Sequence , Endoplasmic Reticulum/metabolism , Gene Expression , Globulins/genetics , Humans , Molecular Sequence Data , Mutagenesis, Insertional , Peptides/genetics , Plants, Genetically Modified , Protein Transport , Recombinant Proteins/biosynthesis , Recombinant Proteins/genetics , Seeds/metabolism , Soybean Proteins/genetics , Glycine max/metabolism , Vaccines , Vacuoles/metabolism
7.
J Biosci Bioeng ; 117(6): 742-8, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24331980

ABSTRACT

Basic 7S globulin (Bg7S), which accumulates in mature soybean (Glycine max) seeds, is an extracellular matrix protein. A large amount of Bg7S is synthesized de novo and is eluted from soybean seeds when immersed in 50-60°C water (hot water treatment, HWT). However, the Bg7S elution mechanism remains unclear. Under HWT, the seeds probably undergo heat stress and flooding stress. To obtain fundamental knowledge related to how Bg7S is eluted from hot-water-treated seeds, this study compared Bg7S elution among soybean cultivars having different flooding tolerance during pre-germination. The amounts of Bg7S eluted from seeds varied significantly among cultivars. Elution was suppressed by seed coats regarded as preventing the leakage of seed contents by rapid water imbibition. Furthermore, Bg7S expression levels differed among cultivars, although the difference did not result from any variation in Bg7S promoter sequences. However, the expression levels of Bg7S under HWT were not associated with the flooding tolerance level. Immunoelectron microscopy revealed that the Bg7S accumulated in the intercellular space of hot-water-treated seeds. Plasma membrane shrinkage was observed. The main proteins eluted from seeds under HWT were located in the extracellular space. This study clarified the mechanism of Bg7S elution from seeds under HWT.


Subject(s)
Antigens, Plant/biosynthesis , Globulins/biosynthesis , Glycine max/metabolism , Seed Storage Proteins/biosynthesis , Seeds/metabolism , Soybean Proteins/biosynthesis , Amino Acid Sequence , Antigens, Plant/genetics , Base Sequence , Globulins/genetics , Globulins/metabolism , Heat-Shock Response , Promoter Regions, Genetic , Protein Transport , Seed Storage Proteins/genetics , Seed Storage Proteins/metabolism , Seeds/ultrastructure , Sequence Analysis, Protein , Soybean Proteins/genetics , Soybean Proteins/metabolism , Glycine max/ultrastructure
8.
Recent Pat Biotechnol ; 7(1): 61-70, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23294401

ABSTRACT

In this research it was attempted to overexpress the acidic subunit, from the 11S amaranth seed globulin termed amarantin, modified with antihypertensive peptides in Escherichia coli Rosetta (DE3) by manipulating some factors in batch fermenter such as growth medium composition, inducer (isopropyl ß-D-thiogalactopyranoside [IPTG] or lactose), air flow, cultivation temperature, agitation speed and induction time. The possibility of using several minimal media and lactose as inducer to increase yields of the recombinant protein was investigated. Previous fermentations at flask level showed that two minimal culture media (A6 and A7) and 0.5% (w/v) lactose presented high yields of the engineered protein expression. Thus, the latter two media were tested at fermenter level, the lactose inducer, and different environmental conditions. Factors with significant effects were identified by Plackett-Burman design with center points and were adjusted at the level suggested and the yields of the recombinant protein were increased from 303.2 to 1,531 mg L(-1) in A6 and from 363.4 to 1,681 mg L(-1) in A7. Unlike some patents where the highest productivity was achieved at 24 h or afterwards, in this research the best productivity of the recombinant acidic subunit was attained at 4 and 6 h of induction using both media, respectively.


Subject(s)
Amaranthus/genetics , Escherichia coli/genetics , Escherichia coli/metabolism , Globulins/biosynthesis , Lactose/metabolism , Plant Proteins/biosynthesis , Bioreactors , Biotechnology/methods , Fermentation , Globulins/chemistry , Globulins/genetics , Patents as Topic , Plant Proteins/chemistry , Plant Proteins/genetics , Recombinant Proteins/biosynthesis , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolism
9.
Recent Pat Biotechnol ; 6(1): 23-31, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22420879

ABSTRACT

The expression in Escherichia coli strain Rosetta of the recombinant acidic subunit from the 11S amaranth seed storage protein (protein ACM3) was studied at flask and at bioreactor levels. This subunit was modified by inserting four Val-Tyr antihypertensive peptides in tandem into its third variable region and also with the tripeptide Ile-Pro-Pro in the Cterminal region. Flasks experiments allowed us to define the best conditions for the preparation and expression and accumulation of the protein ACM3, including the certainty of its presence within the cells especially as an insoluble fraction. The effects of cultivation temperature, aeration rate and agitation speed on the production of the protein ACM3 was tested in a 5-L batch bioreactor. Applying response surface methodology (RSM) we found that the aeration rate was the most significant factor affecting in a positively way the production yields and productivity of the recombinant protein. Temperature had effect only in conjunction to aeration. The highest recombinant acidic subunit concentration (747 mg L-1) and the highest productivity (186 mg L-1 h-1) were attained in 4 h of cultivation when the factors evaluated were controlled at its central values: 0.1 vvm, 300 rpm, and 30.5° C. Results from this study indicate that RSM is an effective technique to maximize the production of this recombinant protein.


Subject(s)
Bioreactors/microbiology , Escherichia coli/metabolism , Globulins/biosynthesis , Seed Storage Proteins/biosynthesis , Analysis of Variance , Fermentation , Recombinant Proteins/biosynthesis , Regression Analysis , Reproducibility of Results
10.
Transgenic Res ; 19(5): 819-27, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20084547

ABSTRACT

A transgenic rice that produces both the alpha' and beta subunits of beta-conglycinin has been developed through the crossing of two types of transgenic rice. Although the accumulation level of the alpha' subunit in the alpha'beta-transgenic rice was slightly lower than that in the transgenic rice producing only the alpha' subunit, the accumulation level of the beta subunit in the alpha'beta-transgenic rice was about 60% higher than that in the transgenic rice producing only the beta subunit. Results from sequential extraction and gel-filtration experiments indicated that part of the beta subunit formed heterotrimers with the alpha' subunit in a similar manner as in soybean seeds and that the heterotrimers interacted with glutelin via cysteine residues. These results imply that the accumulation level of the beta subunit in the alpha'beta-transgenic rice increases by an indirect interaction with glutelin. Immunoelectron microscopy revealed that the alpha' and beta subunits are localized in a low electron-dense region of protein body-II (PB-II) and that alpha' homotrimers in the alpha'beta-transgenic rice seeds seem to accumulate outside of this low electron-dense region.


Subject(s)
Antigens, Plant/biosynthesis , Globulins/biosynthesis , Glycine max/genetics , Oryza/metabolism , Plants, Genetically Modified/metabolism , Seed Storage Proteins/biosynthesis , Soybean Proteins/biosynthesis , Antigens, Plant/chemistry , Antigens, Plant/genetics , Crosses, Genetic , Cysteine/chemistry , Electrophoresis, Polyacrylamide Gel , Gene Expression Regulation, Plant , Globulins/chemistry , Globulins/genetics , Glutens/chemistry , Microscopy, Immunoelectron , Oryza/genetics , Protein Interaction Mapping , Protein Multimerization , Protein Subunits , Recombinant Fusion Proteins/biosynthesis , Recombinant Fusion Proteins/chemistry , Seed Storage Proteins/chemistry , Seed Storage Proteins/genetics , Seeds/metabolism , Soybean Proteins/chemistry , Soybean Proteins/genetics , Transgenes
11.
Int Arch Allergy Immunol ; 145(2): 102-10, 2008.
Article in English | MEDLINE | ID: mdl-17823539

ABSTRACT

BACKGROUND: The major storage protein in soybean seed is beta-conglycinin and this protein has been identified as being responsible for food-allergic reactions in several species. However, the mechanism through which beta-conglycinin induces an allergic reaction has not yet been elucidated. In addition, assessing the antigenic activity of beta-conglycinin by studying the activity of a subunit has rarely been conducted. Therefore, the objective of the present study was to characterize the antigenic specificity of the beta-conglycinin alpha'-subunit. METHODS: We established an Escherichia coli expression system to obtain beta-conglycinin alpha'-subunit. The fusion proteins were then used in a rat model to induce a hypersensitive reaction. Immunoblotting, IgE and IgG1 level, histamine release, and passive cutaneous anaphylaxis reactions and intestinal histology were tested to assess the allergenic activity of the beta-conglycinin alpha'-subunit. RESULTS: Pure beta-conglycinin alpha'-subunit was obtained by expression in E. coli. The recombinant proteins were shown to have the same biological activity as the natural beta-conglycinin alpha'-subunit using immunoblotting analysis. Both the IgE and IgG1 level in serum and the histamine concentration in the intestine were increased while passive cutaneous anaphylactic reactions were induced in Brown Norway rats by intragastric gavage with the alpha'-subunit. Histamine release of mast cells was also elevated in vitro. CONCLUSIONS: Our results indicate that the beta-conglycinin alpha'-subunit possesses an intrinsic immune-stimulating capacity and that it can induce an allergic reaction. Moreover, this study showed that beta-conglycinin alpha'-subunit-induced anaphylaxis is IgE mediated, and mast cell degranulation and histamine release are associated with anaphylactic symptoms.


Subject(s)
Food Hypersensitivity/immunology , Globulins/immunology , Glycine max/immunology , Soybean Proteins/immunology , Animals , Antigens, Plant , Diarrhea/etiology , Diarrhea/immunology , Diarrhea/pathology , Duodenum/immunology , Duodenum/pathology , Escherichia coli , Female , Globulins/biosynthesis , Globulins/genetics , Globulins/toxicity , Histamine Release , Immunoglobulin E/immunology , Immunoglobulin G/immunology , Mast Cells/immunology , Mast Cells/metabolism , Passive Cutaneous Anaphylaxis/immunology , Protein Subunits/immunology , RNA, Plant/genetics , Random Allocation , Rats , Rats, Inbred BN , Recombinant Fusion Proteins/biosynthesis , Recombinant Fusion Proteins/immunology , Recombinant Fusion Proteins/toxicity , Seed Storage Proteins , Soybean Proteins/biosynthesis , Soybean Proteins/genetics , Soybean Proteins/toxicity , Glycine max/genetics
12.
Indian J Biochem Biophys ; 41(1): 57-9, 2004 Feb.
Article in English | MEDLINE | ID: mdl-22896911

ABSTRACT

Five-months-old male albino mice were subjected to an electromagnetic field (EMF) of 5 mT of magnitude with a frequency of 60 Hz for 8hr of single application. Analysis of blood sampled on hourly basis (up to 8 hr) for levels/activities of total protein, albumin, globulin, uric acid, creatinine, cholesterol, and alkaline phosphatase indicated no significant differences (p > 0.05) from that of the control group.


Subject(s)
Electromagnetic Fields , Proteins/radiation effects , Albumins/biosynthesis , Alkaline Phosphatase/biosynthesis , Animals , Cholesterol/biosynthesis , Cholesterol/blood , Creatinine/metabolism , Globulins/biosynthesis , Male , Mice , Time Factors , Tissue Distribution , Uric Acid/metabolism
13.
Biochim Biophys Acta ; 1648(1-2): 99-104, 2003 May 30.
Article in English | MEDLINE | ID: mdl-12758152

ABSTRACT

beta-Conglycinin is composed of three kinds of subunit: alpha, alpha' and beta. A phagocytosis-stimulating peptide sequence (MITLAIPVNKPGR), soymetide, exists in the alpha' subunit of beta-conglycinin. Met at N terminus of the soymetide is essential for the activity. When Thr at the third residue from N terminus of the soymetide is replaced by Phe or Trp, the phagocytosis-stimulating activity greatly increases (ThrMet, Lys-->Thr, Phe, or Trp) into the beta subunit after confirmation of the effects of residue replacements by molecular modeling, suggesting that the introduced mutations might not prevent the correct folding. The studies of circular dichroism (CD), gel filtration and differential scanning calorimetry (DSC) of the mutants (I122M/K124T, I122M/K124F, I122M/K124W) expressed in E. coli demonstrated that they folded and self-assembled similarly to the wild type. This was confirmed by X-ray analysis of I122M/K124W crystal where the biggest residue tryptophane was introduced. The three mutants exhibited phagocytosis activities after digestion by trypsin, and the order was the wild type

Subject(s)
Globulins/chemistry , Glycine max/chemistry , Soybean Proteins/chemistry , Antigens, Plant , Calorimetry, Differential Scanning , Circular Dichroism , Globulins/biosynthesis , Globulins/genetics , Hot Temperature , Models, Molecular , Phagocytosis/physiology , Protein Structure, Tertiary , Seed Storage Proteins , Soybean Proteins/biosynthesis , Soybean Proteins/genetics , Glycine max/genetics
14.
Biosci Biotechnol Biochem ; 66(8): 1751-4, 2002 Aug.
Article in English | MEDLINE | ID: mdl-12353641

ABSTRACT

The application of glutathione to immature soybean cotyledons reduced the accumulation of the beta subunit of beta-conglycinin, and increased the accumulation of most glycinins. Both reduced and oxidized forms of glutathione had these effects. The application of an inhibitor of glutathione synthesis, buthionine sulfoximine, increased accumulation of beta subunit. These results suggest that glutathione is important in affecting the composition of seed storage proteins.


Subject(s)
Globulins/biosynthesis , Glutathione/pharmacology , Glycine max/drug effects , Soybean Proteins/biosynthesis , Antigens, Plant , Buthionine Sulfoximine/pharmacology , Cotyledon/drug effects , Cotyledon/metabolism , Cysteine/metabolism , Electrophoresis, Polyacrylamide Gel , Enzyme Inhibitors/pharmacology , Globulins/metabolism , Glutathione/antagonists & inhibitors , Glutathione/biosynthesis , Glutathione Disulfide/pharmacology , Seed Storage Proteins , Soybean Proteins/metabolism , Glycine max/metabolism
15.
Planta ; 203(1): 44-50, 1997 Sep.
Article in English | MEDLINE | ID: mdl-9299790

ABSTRACT

Narbonin is a 2S protein from the globulin fraction of narbon bean (Vicia narbonensis L.) cotyledons. Its amino acid composition and the pattern of its regulated accumulation in developing seeds led to the suggestion that narbonin could be a storage protein. Therefore, it was expected to be present in protein bodies of the storage tissue cells. Comparison of the cDNA-derived amino acid sequence with a directly determined partial N-terminal sequence revealed that the primary translation product of narbonin mRNA lacks a transient N-terminal signal peptide (V.H. Nong et al., 1995, Plant Mol Biol 28: 61 - 72). Narbonin polypeptides that had been synthesized in a cell-free translation system supplemented with dog pancreas microsomes were not protected against degradation by posttranslationally added proteases (protease protection assay). In accordance with the lack of a signal peptide this indicates that the polypeptide was not cotranslationally sequestered into the microsomes. The protein-body fraction that had been isolated from mature narbon bean cotyledons by a non-aqueous gradient centrifugation procedure was free of narbonin; this was found in the soluble cell fraction. In electron micrographs, narbonin could be localized in the cytoplasm using the immuno gold-labelling technique. Previously, it had already been shown that narbonin is too slowly degraded during narbon bean germination to act as a storage protein. From all these results it has to be concluded that narbonin is a cytoplasmic protein which does not belong to the storage proteins in the restricted sense. Other possible functions are discussed.


Subject(s)
Fabaceae/ultrastructure , Globulins/analysis , Globulins/biosynthesis , Plant Proteins, Dietary/analysis , Plant Proteins, Dietary/biosynthesis , Plants, Medicinal , Animals , Cell-Free System , DNA, Complementary , Dogs , Fabaceae/metabolism , Globulins/chemistry , Microscopy, Immunoelectron , Microsomes/metabolism , Pancreas/metabolism , Plant Proteins, Dietary/chemistry , Protein Biosynthesis , Protein Processing, Post-Translational , RNA, Messenger/metabolism , Seeds/chemistry , Seeds/ultrastructure , Subcellular Fractions/metabolism , Subcellular Fractions/ultrastructure
17.
Plant Physiol ; 115(4): 1629-39, 1997 Dec.
Article in English | MEDLINE | ID: mdl-9414566

ABSTRACT

Seed protein proglobulins were synthesized from cDNAs in reticulocyte lysates. Most proglobulins were recovered as trimers when translation rates were low, but mostly monomers were recovered at high translation rates. The prevalence of monomers was accompanied by elevated amounts of insoluble protein recovered at the bottom of sucrose density gradients. Apyrase treatment of translation mixtures after synthesis, but before significant assembly occurred, drastically reduced trimer assembly and increased the proportion of insoluble aggregate. These observations indicated that ATP is required for protein folding and/or trimer assembly. The appearance of insoluble aggregated protein when rates of synthesis were elevated or when ATP was absent suggested that protein misfolding had occurred. Trimer assembly was stimulated when wheat germ translation mixtures defective in supporting efficient trimer assembly were supplemented with fractions isolated from endoplasmic reticula of developing pea (Pisum sativum) seeds. Molecular chaperones are likely involved in folding and/or assembly of proglobulin trimers both in reticulocyte lysates and in seeds. Consistent with this hypothesis, trimer formation was reduced when carboxymethylated bovine albumin and alpha-casein, considered to mimic proteins with extended chain and molten globular conformations and thereby compete for Hsp70- and Hsp60-type molecular chaperones, respectively, were introduced into translation mixtures.


Subject(s)
Adenosine Triphosphate/metabolism , Globulins/biosynthesis , Pisum sativum/metabolism , Plant Proteins/biosynthesis , Protein Folding , Protein Precursors/biosynthesis , Seeds/metabolism , Animals , Apyrase/metabolism , Caseins/pharmacology , Cattle , Endoplasmic Reticulum/metabolism , Globulins/chemistry , Macromolecular Substances , Molecular Chaperones/metabolism , Plant Proteins/chemistry , Protein Biosynthesis , Protein Precursors/chemistry , Rabbits , Reticulocytes/metabolism , Serum Albumin, Bovine/pharmacology , Transcription, Genetic , Triticum/metabolism
18.
Plant Cell ; 8(12): 2295-307, 1996 Dec.
Article in English | MEDLINE | ID: mdl-8989884

ABSTRACT

In vivo analyses of cis-acting sequence requirements for pre-mRNA splicing in tobacco nuclei have previously demonstrated that the 5' splice sites are selected by their position relative to AU-rich elements within plant introns and by their degree of complementarity to the U1 small nuclear RNA. To determine whether the presence of adjacent introns affects 5' splice site recognition in plant nuclei, we have analyzed the in vivo splicing patterns of two-intron constructs containing 5' splice site mutations in the second intron. These experiments indicated that the splice site selection patterns in plant nuclei are defined primarily by sequences within the intron (intron definition) and secondarily by weak interactions across exons (exon definition). The effects of these secondary interactions became evident only when mutations in the downstream 5' splice site decreased its functionality and differed depending on the availability of cryptic splice sites close to the mutant site. In beta-conglycinin chimeric transcripts containing multiple cryptic 5' splice sites, the presence of an intact upstream intron significantly increased splicing at the downstream 5' splice sites in a polar fashion without activating exon skipping. In a natural beta-conglycinin transcript, which does not contain cryptic 5'splice sites, mutation of the first nucleotide of the downstream intron activated an array of noncanonical 5' and 3' splice sites and some exon skipping.


Subject(s)
Cell Nucleus/metabolism , Exons , Nicotiana/metabolism , Plants, Toxic , RNA Splicing , Soybean Proteins , Antigens, Plant , Base Sequence , Globulins/biosynthesis , Globulins/genetics , Introns , Molecular Sequence Data , RNA Precursors/metabolism , RNA, Plant/metabolism , RNA, Small Nuclear/chemistry , Recombinant Fusion Proteins/biosynthesis , Seed Storage Proteins , Transcription, Genetic
20.
Plant Mol Biol ; 27(1): 205-10, 1995 Jan.
Article in English | MEDLINE | ID: mdl-7865791

ABSTRACT

A number of different cDNA clones corresponding to the most abundant mRNAs present in immature seeds have been isolated from an almond (Prunus amygdalus cv. Texas) immature seed cDNA library. Those corresponding to proteins involved in storage processes have been further characterized. Two of these cDNAs (PA3BF1 and PA3BE12) code for the almond globulins (prunins), the main family of storage proteins synthesized in seeds during embryogenesis, and another cDNA (PA3BA1) codes for the 15.7 kDa almond oleosin, a protein located on the surface of oil bodies in plant seeds. These cDNAs have been sequenced and their expression during almond fruit development has been studied. Their expression is seed-specific and localized in cotyledons around 100 days after flowering. Both prunin and oleosin genes are present in one or two copies in the almond genome.


Subject(s)
Genes, Plant/genetics , Nuts/genetics , Plant Proteins/genetics , Seeds/genetics , Amino Acid Sequence , DNA, Complementary/genetics , Gene Library , Globulins/biosynthesis , Globulins/genetics , Membrane Proteins/biosynthesis , Membrane Proteins/genetics , Molecular Sequence Data , Nuts/growth & development , Plant Proteins/biosynthesis , Seeds/growth & development , Sequence Homology, Amino Acid , Legumins
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