• Korean Journal of Soil Science and Fertilizer
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• v.49 no.1
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• pp.44-52
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• 2016

Plants response to phosphate starvation include the changes of activity of some enzymes, such as phosphatases, fructose-1,6-bisphosphatase, sucrose-phosphate synthase and nitrate reductase. In this study, to determine the effects of phosphate starvation on the change of activities of acid and alkaline phosphatase, fructose-1,6-bisphosphatase, sucrose-phosphate synthase, and nitrate reductase were studied in melon seedlings (Cucumis melo L.). The content of the protein and chlorophyll tended to relatively reduced in melon seedlings subjected to phosphate starvation. Acid phosphatase activity in first and second leaves of melon seedlings was relatively higher than that of third and fourth leaves of seedlings in 14 days after phosphate starvation treatment, respectively. Active native-PAGE band patterns of acid phosphatase in melon leaves showed similar to activities of acid phosphatase, whereas alkaline phosphatase activity was different from the change in the activity of acid phosphatase. Inorganic phosphate content in melon seedlings leaves was constant. The changes of Fructose-1,6-bisphosphatase and sucrose phosphate synthase activities showed similar patterns in melon seedlings leaves, and between these enzymes activities and phosphate nutrition negatively related. Fructose-1,6- bisphosphatase and sucrose phosphate synthase activities showed significant difference in second and fourth leaves, but nitrate reductase showed significant difference in first and second leaves in 14days after phosphate starvation treatment. We concluded that phosphate nutrition could affect the distribution of phosphate, carbon and nitrogen in melon seedlings.

• KSBB Journal
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• v.22 no.5
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• pp.345-350
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• 2007

Phosphosugars are found in all living organisms and are commercially valuable compounds with possible applications in the development of a wide range of specialty chemicals and medicines. In carbohydrate metabolism, fructose 6-phosphate (F6P) is an essential intermediate formed by phosphorylation of 6' position of fructose in glycolysis, gluconeogenesis, pentose phosphate pathway and Calvin cycle. In glycolysis, F6P lies within the glycolysis metabolic pathway and is produced by isomerisation of glucose 6-phosphate. For large-scale production, F6P could be produced from starch using many enzymes such as pullulanase, starch phosphorylase, isomerase and mutase. In enzymatic reactions carried out at high temperatures, the solubility of starch is increased and microbial contamination is minimized. Thus, thermophile-derived enzymes are preferred over mesophile-derived enzymes for industrial applications using starch. Recently, we reported the production of glucose 1-phosphate (G1P) from starch by Thermus caldophilus GK24 enzymes. Here we report the production of F6P from starch through three steps; from starch to glucose 1-phosphate (glucan phosphorylase, GP), then glucose 6-phosphate (phosphoglucomutase, GM) and then F6P (phosphoglucoisomerase, GI). Using 200 L of 1.2% soluble starch solution in potassium phosphate buffer, 1,253 g of G1P were produced. Then, 30% yields of F6P were attained at the optimum reaction conditions of GM : G1 (1 : 2.3), 63.5$^{\circ}C$, and pH 6.85. The optimum conditions were found by response surface methodology and the theoretical values were confirmed by the experiments. The optimum starch concentrations were 20 g/L under the given conditions.

• Molecules and Cells
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• v.27 no.6
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• pp.641-649
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• 2009

Pyrophosphate:fructose-6-phosphate 1-phosphotransferase (PFP) catalyzes the reversible interconversion of fructose-6-phosphate and fructose-1,6-bisphosphate, a key step in the regulation of the metabolic flux toward glycolysis or gluconeogenesis. To examine the role of PFP in plant growth, we have generated transgenic Arabidopsis plants that either overexpress or repress Arabidopsis PFP subunit genes. The overexpressing lines displayed increased PFP activity and slightly faster growth relative to wild type plants, although their photosynthetic activities and the levels of metabolites appeared not to have significantly changed. In contrast, the RNAi lines showed significantly retarded growth in parallel with the reduced PFP activity. Analysis of photosynthetic activity revealed that the growth retardation phenotype of the RNAi lines was accompanied by the reduced rates of $CO_2$ assimilation. Microarray analysis of our transgenic plants further revealed that the altered expression of $AtPFP{\beta}$ affects the expression of several genes involved in diverse physiological processes. Our current data thus suggest that PFP is important in carbohydrate metabolism and other cellular processes.

• The Korean Journal of Pharmacology
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• v.26 no.2
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• pp.121-126
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• 1990

The contractility of isolated rat atria, suspended in Krebs-Ringer bicarbonate medium containing 5.5mM glucose, was depressed approximately 50% by 0.1 mM of lidocaine. Partial recovery of the lidocaine-depressed contractility was achieved by the metabolizable substrates pyruvate, acetate, and fructose, but not by addition of glucose. Glucose produced the dose-dependent increase in the force of contraction of normal atria, whereas pyruvate, acetate, and fructose produced no significant effect in the contractile activity of the normal atria. In the absence of exogenous glucose lidocaine produced more marked depression of atrial contractility than that in the presence of exogenous glucose. The results of this study may confirm that the utilization of cardiac glycogen is also inhibited by lidocaine at sites of the glucose phosphate isomerase step or step between glycogen to glucose-6-phosphate.

• Journal of Applied Biological Chemistry
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• v.58 no.3
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• pp.227-232
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• 2015

A microarray study has been employed to understand changes of gene expression in E. coli KD43162 resistant to ampicillin, ampicillin-sulbactam, piperacillin, piperacillin-tazobactam, cefazolin, cefepime, aztreonam, imipenem, meropenem, gentamicin, tobramycin, ciprofloxacin, levofloxacin, moxifloxacin, fosfomycin, and trimethoprim-sulfamethoxazole except for amikacin using disk diffusion assay. Using Sodium dodecyl sulphate-polyacrylamide gel electrophoresis and MALDI-TOF MS analyses, 36 kDa of outer membrane proteins (OMPs) was found to be deleted in the multidrug resistant E. coli KD 43162. Microarray analysis was used to determine up- and down-regulated genes in relation to multidrug resistant E. coli KD43162. Among the up-regulated genes, these genes were corresponded to express the proteins as penicillin-binding proteins (PBPs), tartronate semialdehyde reductase, ethanolamine utilization protein, shikimate kinase I, allantoinase, predicted SAM-dependent methyltransferase, L-glutamine: D-fructose-6-phosphate aminotransferase (GFAT), phospho-glucosamine mutase, predicted N-acetylmannosamine kinase, and predicted N-acetylmannosamine-6-P epimerase. Up-regulation of PBPs, one of primary target sites of antibiotics, might be responsible for the multidrug resistance in E. coli with increasing amount of target sites. Up-regulation of GFAT enzyme may be related to the up-regulation of PBPs because GFAT produces N-acetylglucosamine, a precursor of peptidoglycans. One of GFAT inhibitors, azaserine, showed a potent inhibition on the growth of E. coli KD43162. In conclusion, up-regulation of PBPs and GFATs with the loss of 36 kDa OMP refers the multidrug resistance in E. coli KD 43162.

• Journal of Microbiology and Biotechnology
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• v.23 no.6
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• pp.785-793
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• 2013

We studied the effects of 2 different dosages of high-molecular-weight poly-${\gamma}$-glutamic acid (hm ${\gamma}$-PGA) derived from Bacillus subtilis chungkookjang on lipid metabolism in a high-fructose diet-induced hypertriglyceridemic animal model. For 4 weeks, rats were fed either AIN-93 diet (normal control, NC; n = 10) or modified AIN-93 diet in which cornstarch was substituted with 63% fructose (n = 30) to induce hypertriglyceridemia. After 4 weeks, the hypertriglyceridemic rats were treated with daily oral doses of 0 mg (hypertriglyceridemic control, HC), 2.5 mg (hypertriglyceridemic, low hm ${\gamma}$-PGA, HL), or 5 $mg{\cdot}kg{\cdot}bw^{-1}{\cdot}d^{-1}$ (hypertriglyceridemic, high hm ${\gamma}$-PGA, HH) hm ${\gamma}$-PGA for 4 weeks. The HL and HH groups exhibited significantly lower levels of serum triglyceride, total cholesterol, LDL cholesterol, and free fatty acids than the HC group. The administration of hm ${\gamma}$-PGA reduced serum ALT and AST levels. The activities of lipogenic enzymes such as hepatic malic enzyme and glucose-6-phosphate dehydrogenase as well as glucose-6-phosphate dehydrogenase mRNA expression were significantly decreased by hm ${\gamma}$-PGA administration (p < 0.05). These results indicate that hm ${\gamma}$-PGA has an anti-hypertriglyceridemic effect in high-fructose diet-induced hypertriglyceridemic rats.

• Microbiology and Biotechnology Letters
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• v.21 no.1
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• pp.82-87
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• 1993

Fourteen samples of kimchies and soy bean pastes were used to isolate strictly anaerobic bacteria on complex BL agar and on a selective BS agar for bifidus bacteria. About $10^7$ ~ $10^8$ colonies per g sample were developed on BL agar under strictly anaerobic conditions, while BS agar supported the growth of $10^3$ ~ $10^6$ colonies per gram sample at the same condition. All colonies developed on BS agar at anaerobic conditions grew in aerobic conditions and did not show fructose6-phosphate phosphoketolase activity. Type cultures of Bifidobacterium did not grow in PYG medium containig more than 3% NaCI. From these results it is conduded that salted fermented food cannot support the growth of strictly anaerobes induding Bifidobactenum.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.6
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• pp.748-756
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• 2000

Effects of xanthine (X), xanthine oxidase (XO), and catalase (C), $H_2O_2$, and carbohydrates on sperm capacitation, acrosome reaction, and fertilizing ability in vitro were examined. Glucose alone, but not fructose, supported the maximum rate of sperm capacitation and acrosome reaction. However, in the combination of X, XO, and C (XXOC) or $H_2O_2$, fructose alone also supported maximum capacitation, acrosome reaction, and fertilization. Either insufficient or excessive amounts of $H_2O_2$ decreased sperm capacitation and the acrosome reaction. In order to understand how glucose generates $H_2O_2$ or other reactive oxygen species in sperm cells, 6-aminonicotinamide, an inhibitor of the pentose-phosphate pathway (PPP), and apocynin, an inhibitor of NADPH oxidase, were added to sperm suspensions in glucose-containing medium. Results appeared that sperm capacitation, acrosome reaction, and fertilization were consequently inhibited by either one of these compounds. These inhibitory effects were nullified by addition of XXOC. These results support the hypothesis that glucose, in addition to being a substrate for glycolysis, facilitates sperm capacitation and the acrosome reaction by generating reactive oxygen species through G-6-P dehydrogenase and NADPH oxidase.

• Parasites, Hosts and Diseases
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• v.51 no.2
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• pp.155-163
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• 2013

This study aimed to evaluate the efficacy of fructose-1,6-bis phosphate aldolase (SMALDO) DNA vaccination against Schistosoma mansoni infection using different routes of injection. The SMALDO has been cloned into the eukaryotic expression vector pcDNA3.1/V5-His TOPO-TA and was used in injecting Swiss albino mice intramuscularly (IM), subcutaneously (SC), or intraperitoneally (IP) ($50{\mu}g/mouse$). Mice vaccinated with non-recombinant pcDNA3.1 served as controls. Each group was immunized 4 times at weeks 0, 2, 4, and 6. Two weeks after the last booster dose, all mice groups were infected with 80 S. mansoni cercariae via tail immersion. At week 8 post-infection, animals were sacrificed for assessment of parasitological and histopathological parameters. High anti-SMALDO IgG antibody titers were detected in sera of all vaccinated groups (P<0.01) compared to the control group. Both the IP and SC vaccination routes resulted in a significant reduction in worm burden (46.2% and 28.9%, respectively, P<0.01). This was accompanied by a significant reduction in hepatic and intestinal egg counts (41.7% and 40.2%, respectively, P<0.01) in the IP group only. The number of dead eggs was significantly increased in both IP and IM groups (P<0.01). IP vaccination recorded the highest significant reduction in granuloma number and diameter (54.7% and 29.2%, respectively, P<0.01) and significant increase in dead miracidia (P<0.01). In conclusion, changing the injection route of SMALDO DNA vaccination significantly influenced the efficacy of vaccination. SMALDO DNA vaccination via IP route could be a promising protective and antipathology vaccine candidate against S. mansoni infection.

• KSBB Journal
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• v.11 no.3
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• pp.374-379
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• 1996

The production of extracellular mannitot by an efficient mannitol-producing bacterium, Lactobacillus sp. KY-107 was studied in shake flask culture using the modified MRS medium. Maximum mannitol production was obtained with fructose as the sole carbon source. Within 95 hours of incubation, a final concentration of 70g/L of mannitol from 100g/L fructose was obtained with an indicated yield of 86% based on fructose consumed. However, higher concentrations of fructose could not effectively be transformed to mannitol due to a lack of osmotolerance. The strain produced no other polyols such as glycerol and sorbitol as by-products. Yeast extract was best nitrogen source and high levels of inorganic phosphate up to 10g/L did not show any detrimental effect for mannitol formation. Manganese ion played important role in both cell growth and mannitol production. The optimum culture temperature and initial pH were $35^{\circ}C$ and 6-8, respectively.