Fawzy Georges

The challenges which face the world today can be summed up in a few words: An increasingly congested world with dwindling areas of viable cultivated land and accelerating climate instability. The combined effect of these realities, together with the trend of striving to extend the average human life, puts the world on the path toward future catastr...

Genome editing of crop plants is a rapidly advancing technology whereby targeted mutations can be introduced into a plant genome in a highly specific manner and with great precision. For the most part, the technology does not incorporate transgenic modifications and is far superior to conventional chemical mutagenesis. In this study we bring into f...

Faba bean (Vicia faba L.) has been little examined from a genetic or genomic perspective despite its status as an established food and forage crop with some key pharmaceutical factors such as vicine and convicine (VC), which provoke severe haemolysis in genetically susceptible humans. We developed next-generation sequencing libraries to maximize in...

Low phytic acid (lpa) crops are low in phytic acid and high in inorganic phosphorus (Pi). In this study, two lpa pea genotypes, 1-150-81, 1-2347-144, and their progenitor CDC Bronco were grown in field trials for two years. The lpa genotypes were lower in IP6 and higher in Pi when compared to CDC Bronco. The total P concentration was similar in lpa...

Seeds of low phytic acid (lpa) pea lines are low in phytic acid (IP6) and high in inorganic phosphorus (Pi). The present study was aimed at biochemical and molecular characterization of two lpa pea lines, 1-150-81, 1-2347-144, and their progenitor CDC Bronco. The lpa lines did not significantly differ from CDC Bronco in the agronomic traits assesse...

Phosphatidylinositol-specific phospholipase C2 (PLC2) is a signaling enzyme with hydrolytic activity against membrane-bound phosphoinositides. It catalyzes the cleavage of phosphatidylinositol(4,5)bisphosphate (PtdIns(4,5)P 2) into two initial second messengers, myo-inositol-1,4,5-trisphosphate (InsP 3) and diacylglycerol (DAG). The former, as well...

The pattern of phytate, inorganic and total phosphorus accumulation was assessed in seeds of low-phytate lines and compared with normal phytate line. The critical stage when phosphorus storage shifts from phytate to inorganic form in the low phytate lines will be discussed.

Background myo-Inositol (Ins) metabolism during early stages of seed development plays an important role in determining the distributional relationships of some seed storage components such as the antinutritional factors, sucrose galactosides (also known as raffinose oligosaccharides) and phytic acid (PhA) (myo-inositol 1,2,3,4,5,6-hexakisphosphate...

The synthesis of 2,3,6-trideoxy-3-dimethylamino-D-arabino-hexose hydrochloride (10) (D-angolosamine, a constituent of the antibiotic, angolamycin) is described. First, a simplified procedure for the preparation of methyl 6-deoxy-α-D-glucopyranoside from methyl α-D-glucopyranoside is recorded. The deoxy derivative served as the starting point for se...

Starting from methyl 3,6-dideoxy-3-nitro-α-D-glucopyranoside (1) and proceeding through its 4-mesylate (2) and 2,4-dimesylate (3), respectively, methyl 3,4,6-trideoxy-3-nitro-α-D-xylo-hexopyranoside (4) and methyl 2-O-acetyl-3,4,6-trideoxy-3-nitro-α-D-threo-hex-3-enopyrano-side (5) were prepared. The 4,6-O-benzylidene derivatives (6, 8, and 10) of...

Conditions for the replacement of the 3-acetoxy group of ethyl 3,4,6-tri-O-acetyl-2-deoxy-2-oximino-α-D-arabino-hexopyranoside (1) by nucleophiles including azide, phthalimide, hydride, and thiophenoxide are reported. The reaction was discovered through the formation of dimeric and trimeric derivatives of deacetylated 1 in the course of its alkalin...

Evidence for a small size protein (ca. 3500 kDa) exhibiting epitopic homology to the Atlantic winter flounder antifreeze protein (AFP) is found in the snow molds Coprinus psychromorbidus, Myriosclerotinia borealis, and Typhula incarnata. The protein shows strong cross-reactivity with antisera specific for the flounder AFP. Preliminary studies sugge...

Cultivated faba bean (Vicia faba) is widely used as human food, especially in Europe, Northern Africa and China. In view of its superior feeding value over field peas or other legumes, it is also widely used as animal feed for a variety of species. V. faba also contains medically important components such as 3,4-dihydroxyphenylalanine (levo-DOPA, L...

Phosphatidylinositol-specific phospholipase C (PtdIns-PLC2) plays a central role in the phosphatidylinositol-specific signal transduction pathway. It catalyses the hydrolysis of membrane-bound phosphatidylinositol 4,5-bisphosphate to produce two second messengers, sn-1,2-diacylglycerol and inositol 1,4,5-trisphosphate. The former is a membrane acti...

The utility of defatted seed meal from many crops such as canola (Brassica napusL.) is limited by the presence of antinutritional factors, including sucrose galactosides, raffinose, and stachyose. Anaerobic breakdown of these sugars in the digestive tract of livestock is a major source of production of farm gases. In this report, the gene encoding...

The raffinose family of oligosaccharides (RFO) is a series of complex carbohydrates stored in seeds of many plant families, especially in legumes. The digestive system of nonruminant animals, including that of humans, cannot break down all of the chemical bonds in these carbohydrates therefore, catabolism is achieved anaerobically by intestinal flo...

Brassica species represent several important crops including canola (Brassica napus). Understanding of genetic elements that contribute to seed-associated functions will impact future improvements in the canola crop. Brassica species share a very close taxonomic and molecular relationship with Arabidopsis thaliana. However, there are several subtle...

Potato is an important world crop but its cultivation is relatively limited by its sensitivity to salt-stress. Auto- and hetero-grafting was used to examine the effect of rootstock and abscisic acid (ABA) on expression of the Ca2+-storage protein calreticulin (CR) and salt-stress tolerance in potato. Sibling-selected diploid clones of potato (S. tu...

The cloning and identification of full-length cDNA fragments coding for the Brassica napus phosphatidylinositol-specific phospholipase C2 (BnPLC2), phosphatidylinositol 3-kinase (BnVPS34) and phosphatidylinositol synthase (BnPtdIns S1) is described. In addition, two complementary fragments (120 nucleotides long) corresponding to Arabidopsis PtdIns...

Approximately 5000 plaques derived from a Brassica napus L. (canola) seed-cDNA library representing 15 days after pollination (DAP) were differentially screened for highly expressed genes at the early stages of seed development. Analysis of 104 differentially expressed sequence tags revealed 54 unique genes, of which 33 had putative homologues desc...

Proteins are vulnerable to spontaneous, covalent modifications that may result in alterations to structure and function. Asparagines are particularly labile, able to undergo deamidation through the formation of a succinimide intermediate to produce either aspartate or isoaspartate residues. Although aspartates cannot undergo deamidation they can fo...

Enzyme I mutants of the Salmonella typhimurium phosphoenolpyruvate:sugar phosphotransferase system (PTS), which show in vitro intragenic complementation, have been identified as Arg126Cys (strain SB1690 ptsI34), Gly356Ser (strain SB1681 ptsI16), and Arg375Cys (strain SB1476 ptsI17). The mutation Arg126Cys is in the N-terminal HPr-binding domain, an...

The structure of the N-terminal domain of enzyme I complexed with histidine-containing protein (HPr) has been described by multi-dimensional NMR. Residues in HPr involved in binding were identified by intermolecular nuclear Overhauser effects (Garrett et al. 1999). Most of these residues have been mutated, and the effect of these changes on binding...

The monoclonal antibody Jel42 is specific for the Escherichia coli histidine-containing protein, HPr, which is an 85 amino acid phosphocarrier protein of the phosphoenolpyruvate:sugar phosphotransferase system. The binding domain (Fv) has been produced as a single chain Fv (scFv). The scFv gene was synthesized in vitro and coded for pelB leader pep...

Frost tolerance was determined in Norwegian varieties of groups I and I11 of the psychrophilic fungus Typhula ishikariensis. When mycelia of group I and Ill strains were rapidly frozen to -40° in a program freezer at a cooling rate of 20?C/h, the regrowth of group I strains was delayed at their optimal growth temperature (lO1'C), whereas the regro...

Unlabelled: We studied the direct effect of reactive hydroxyl precursors and inhibitors on CD4+ T-cell function. We used hydrogen peroxide plus ferrous chloride as the hydroxyl radical-generating system and di-methyl sulphourea, di-methyl sulfoxide, pyrrolidine dithiocarbonate, methanol, and ethanol, at a noncytotoxic concentration, as inhibitors....

Histidine-containing protein (HPr) is a phosphocarrier protein of the bacterial phosphoenolpyruvate:sugar phosphotransferase system. HPr is phosphorylated at the active site residue, His15, by phosphoenolpyruvate-dependent enzyme I in the first enzyme reaction in the process of phosphoryl transfer to sugar. In many Gram-positive bacterial species H...

The Arabidopsis thaliana genes kin1 and cor6.6 belong to the same family and were expressed at higher levels following low temperature and ABA treatments. In an attempt to elucidate the mechanism of gene regulation by low temperature, the relationship between low-temperature- and abscisic acid (ABA)-induced gene expression and possible differential...

Histidine-containing protein, HPr, of the phosphoenolpyruvate:sugar phosphotransferase system in Escherichia coli, when incubated at elevated temperatures forms many species of protein. The two major species are HPr-1 and HPr-2, which have been shown to lack one or two amides, respectively (Anderson, B., Weigel, N., Kundig, W., and Roseman, S. (197...

Histidine-containing protein, HPr, of the Escherichia coli phosphoenolpyruvate:sugar phosphotransferase system has an active site His-15 that is phosphorylated to form N delta 1-P-histidine. The nearby conserved residue, Arg-17, has been replaced by: lysine, histidine, glutamate, glycine, serine, and cysteine. All mutations resulted in impairment o...

A novel approach is described, through which the transcriptional orientation of cloned genes is manipulated without further subcloning. This is achieved through a restriction/ligation process (without changing the test tube) leading to approx. 1:1 mixture of both possible orientations. The plasmid containing the reversed orientation is easily disti...

Histidine-containing protein, HPr, of the Escherichia coli phosphoenolpyruvate:sugar phosphotransferase system has an active site that involves His-15, which is phosphorylated to form a N delta 1-P-histidine, Arg-17, and the carboxy-terminal residue Glu-85. Mutant HPrs with alterations to the three C-terminal residues, Glu-85, Leu-84, and Glu-83, w...

Thirty-four of the 85 residues of the histidine-containing protein HPr of the Escherichia coli phosphoenolpyruvate:sugar phosphotransferase system have been changed by site-directed mutagenesis. Many of the mutations have wild-type activity suggesting an unaltered tertiary structure but have altered binding to three monoclonal antibodies: Jel42, Je...

A monoclonal antibody against wheat germ sucrose synthetase is developed and characterized. Its use in studying the effect of cold acclimation on the expression of sucrose synthetase in winter and spring wheat plants is described. The antibody shows cross-reactivity with sucrose synthetase from maize and pea plants, as well as carrot cells. A gradu...

A synthetic gene coding for the winter flounder antifreeze protein (AFP) has been constructed. A new strategy for the synthesis has been employed such that one strand of the duplex was chemically synthesized and the other was produced enzymatically by chain extension. The chemically synthesized blocks were constructed so that the second strand was...

Transient expression of chloramphenicol acetyl transferase gene has been detected in cultured barley (Hordeum vulgare L. cv. Heartland) cells and freshly isolated immature zygotic embryos (cv. Ellice) following the introduction of the gene by microprojectile bombardment. The DNA expression vector used to introduce the CAT gene, pCaMVI1CN, is a pUC8...

Exposure of plant tissues to the winter flounder antifreeze protein (AFP) has revealed three novel properties by which plant cold hardiness may be improved. Firstly, vacuum infiltration of the protein into leaves of potato, canola (Brassica napus) and Arabidopsis thaliana resulted in a significant depression of the spontaneous freezing temperature...

Keywords:Phosphoryl transfer;Epitopes;Two-dimensional NMR;Protein structure;X-ray diffraction;Sugar transport

A unique esterase isozyme z with very low electrophoretic mobility on the anionic polyacrylamide gel (PAGE) was found in the medium of a non-embryogenic (Ca-4) line of cultured carrot (Daucus carota L.) cells. The protein corresponding to this esterase isozyme z was purified by electroelution from preparative PAGE and the esterase migrated as a sin...

A group of uniquely designed single-stranded oligodeoxyribo-nucleotides that form hairpin loops were synthesized. These oligonucleotides can be ligated to other synthetic single-stranded fragents differing in length and design without the need for external annealing templates. A novel approach to building a limitless variety of mobile multiple-rest...

Two major groups of esterase isozymes were identified in extracts of carrot (Daucus carota L. var. Royal Chantaney) cells cultured in vitro using polyacrylamide gel electrophoresis. In the slow moving group, an isozyme marked «y» was absent and another marked «x» was present in the embryogenic cell line (Ca-7) as compared to the non-embryogenic cel...

By inserting nitrocellulose strips into agarose gels alongside the electrophoresed lanes and passing an electric current perpendicularly in the direction of the strips, highly efficient transfer of DNA bands onto the membrane in the form of concentrated dots is achieved. DNA detection limits by this technique are enhanced, at least three times as v...

A 355 base pair (bp) DNA sequence coding for human preproinsulin has been assembled by joining a synthetic DNA leader sequence coding for 24 preregion amino acids to the previously synthesized DNA duplex of 277 bp constituting the sequence of BCA chain. It was next cloned in M13 mp8 single-stranded bacteriophage and subjected to site-specific mutag...

A 74-bp DNA sequence coding for the pre sequence of human preproinsulin and containing EcoRI termini was synthesized by the chemical enzymatic method, joined with previously synthesized proinsulin DNA, and cloned in the M13mp8 vector. A clone pNB82-121 was identified by DNA sequence which confirmed the correct orientation of the pre sequence to the...

It has been suggested that a sequence in the RNA transcript that can form a stem and loop structure, followed by the sequence CAAUCAA, is the signal for ρ-dependent transcription termination. We tested this hypothesis by synthesizing a DNA duplex whose sequence corresponds to a region of the λtR1 terminator that contains these structural features....

Das aus D-Glucaltriacetat hergestellte Tri-O-acetyl-2-desoxy- 2-oximino-D-arabino-hexopyranosid (I) reagiert mit nucleophilen Reagentien wie Natriumazid, Phthalimidkalium, Natriumborhydrid oder Natriumthiophenolat unter Substitution des 3-Acetoxyrestes.

Mesylierung des Didesoxy-a-D-glucopyranosids (I) führt zu dem Mono- (IIa) und dem Dimesyl- Derivat (IIb) (Nebenprodukt).

Die aus Methyl-6-desoxy-oz-D-glucopyranosid (nach einem vereinfachten Verfahren aus Methyl-oz-D-glucopyranosid erhalten) dargestellte Ausgangsverbindung (Ia), ihre Derivate (Ib)-(Ie) (Gesamtausbeute 38%), sowie das Pyranosid (II) werden nach dem für die L-Reihe beschriebenen Verfahren synthetisiert.

Aus dem Nitro-cyclohexan-1,3-diol (Ia) entsteht über das Mesylat (Ib) das Nitro-hydroxy-cyclohexen (II).

This research work has been planned with the intention of proving the absolute configuration of lactobacillc acid. During the course of this work, attempts have been made to synthesize cis-2-carboxycyclopropane- l-.acetic acid as,v,a suitable resolvable material. As the results were not satisfactory, the synthesis of ci,s-2-carboxycyclopropane-l-pr...