• Mycobiology
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• v.41 no.3
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• pp.145-148
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• 2013

Vegetative growth signaling of the opportunistic human pathogenic fungus Aspergillus fumigatus is mediated by GpaA ($G{\alpha}$). FlbA is a regulator of G protein signaling, which attenuates GpaA-mediated growth signaling in this fungus. The flbA deletion (${\Delta}flbA$) and the constitutively active GpaA ($GpaA^{Q204L}$) mutants exhibit enhanced proliferation, precocious autolysis, and reduced asexual sporulation. In this study, we demonstrate that both mutants also show enhanced tolerance against $H_2O_2$ and their radial growth was approximately 1.6 fold higher than that of wild type (WT) in medium with 10 mM $H_2O_2$. We performed quantitative PCR (qRT-PCR) for examination of mRNA levels of three catalase encoding genes (catA, cat1, and cat2) in WT and the two mutants. According to the results, while levels of spore-specific catA mRNA were comparable among the three strains, cat1 and cat2 mRNA levels were significantly higher in the two mutants than in WT. In particular, the ${\Delta}flbA$ mutant showed significantly enhanced and prolonged expression of cat1 and precocious expression of cat2. In accordance with this result, activity of the Cat1 protein in the ${\Delta}flbA$ mutant was higher than that of $gpaA^{Q204L}$ and WT strains. For activity of the Cat2 protein, both mutants began to show enhanced activity at 48 and 72 hr of growth compared to WT. These results lead to the conclusion that GpaA activates expression and activity of cat1 and cat2, whereas FlbA plays an antagonistic role in control of catalases, leading to balanced responses to neutralizing the toxicity of reactive oxygen species.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.1
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• pp.7-12
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• 1994

This study was designed to investigate the effects of dietary iron supplementationon ${\delta}-aminolevulinic$ acid dehydratase (DALAD) activity and liver damage of the lead(Pb)-administered rats. The iron (Fe) supplement levels were 100 ppm(Fe100) and 500ppm(Fe500) and the Pb-exposed rats were given 2, 000ppm-Pb in drinking water, while control rats were given neigher iron nor lead. Hematocrit was lower in the Pb, Fe100 -Pb, Fe500-Pb group than in the control, but was not affected by the Pb adminstration when the rats fed the Fe supplementation diet. DALAD activity were reduced by Pb added but, were higher in the Fe500-Pb group than in the Fe100 -Pb group. No significant difference was found in serum Pb content due to Pb administration and Fe supplementation. The liver Pb contentwas higher in the Fe supplementation group than in the Pb-group. Level of serum FE was lower in the Pb added groups than in the control group. Liver Fe contents were increased with Pb administration and higher in the Fe supplement groups than in the Pb-group. Levels of serum and liver copper was decreased with the Fe supplementation. Aminotransferase activity of serum and liver were increased in the Pb group.

• Journal of Microbiology and Biotechnology
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• v.17 no.1
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• pp.81-88
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• 2007

The sprC gene encodes Streptomyces griseus protease C (SGPC), a bacterial chymotrypsin-like serine protease. Because the published data on sprC was not complete, we cloned and analyzed a new DNA fragment spanning downstream to upstream of the sprC gene from S. griseus IFO13350. The cloned 2.3-kb DNA fragment was placed on a high-copy number plasmid and introduced into Streptomyces lividans TK24. Chymotrypsin activity of the transformant was 8.5 times higher than that of the control after 3 days of cultivation and stably maintained until 9 days of cultivation, which dearly indicated that the cloned 2.3-kb fragment contained the entire sprC gene with its own promoter. When the same construct was introduced in the S. griseus IFO13350 (wild strain) and its two mutant strains in the A-factor regulatory cascade, ${\Delta}adpA$ and HO1, the chymotrypsin activity increased fivefold only in the ${\Delta}adpA$ strain. Transcriptional analysis based on RT-PCR revealed that the sprC gene is normally transcribed in both strains; however, earlier transcription was observed in the wild strain compared with the ${\Delta}adpA$ strain. A gel mobility shift assay showed that the AdpA protein did not bind to the promoter region of sprC. All these data clearly indicate that the expression of sprC is not dependent on the AdpA protein, but is distinctly regulated from other chymotrypsin genes composing an AdpA regulon. Earlier morphological differentiation was observed in S. lividans TK24, and S. griseus IFO13350 and HO1, transformed with the expression vector. The transformant of S. griseus ${\Delta}adpA$ formed markedly larger colonies. Antisense repression of sprC resulted in severe decrease of chymotrypsin activity, down to one-third of the control, and delayed morphological differentiation. All these data suggest that SGPC is related to normal morphogenesis in S. griseus.

• Korean journal of food and cookery science
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• v.10 no.1
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• pp.24-28
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• 1994

The effects of synthetic and carrot carotene on the browning of polyphenolics extracted from potato for eliminating the effects of other components in potato which inhibit the browning of potato juice and the potato polyphenol oxidase (PPO) activity were investigated. Total phenolics content in potato sample was 1.854mg/g D.W. and PPO activity was 100 unit. Delta 'L'value of polyphenolics extracted from potato decreased makedly, but that of potato with carrot decreased little by little. Potato with P-carotene showed a little decrease after 50 min. At the same time, polyphenolics extracted from potato were mixed with carotene extracted from carrot or with syntetic $\beta$-carotene. As the results, the delta 'L'value of the former increased but decreased similarly to the latter after 1 hour. The effects of enzyme and substrate concentration on the browning of PPO extracted from potato were investigated. Optimum enzyme concentration was 10% and optimum substrate concentration was 13.3% $\beta$-carotene concentration did not appear to influence significantly on PPO activity.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.4
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• pp.469-474
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• 1995

The effects of sperific inhibitors of $3\beta-hydroxy-\Delta^5-steroid\;dehydrogenase$ $(3\beta-HSD;\;an\;enzyme\;catalyzing\;conversion\;of \Delta^5\;steroids\;to\;\Delta^4 steroids),$ cyanoketone and trilostane, on $^3H-pregnenolone$ metabolism in isolated ovarian thecal layers have been investigated in vitro. At all doses of cyanoketone $(10^{-5}\;and\;10^{-4}\;M)$ and trilostane $(10^{-5}\;and\;10^{-4}\;M)$ $(3\beta-HSD$ enzyme activity that transforms pregnenolone to $17\alpha-hydroxyprogesterone$ was inhibited in the thecal layers. Trilostane appeared to be more efficient than cyanoketone. Trilostane at doses of $10^{-8},\;10^{-7},\;10^{-6},\;and\;10^{-5},\;M/ml$ caused a dose-response inhibition of $\Delta^4$ steroids accumulation in the medium from pregnenolone, but not completely blocked the conversion of $\Delta^5\;to\;\Delta^4$ steroids.

• Horticultural Science & Technology
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• v.32 no.3
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• pp.353-358
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• 2014

Hot water dipping test was conducted for chicon to restrict red discoloration of its basal part which impairs the product value during sales. Hot water dipping treatment was given to chicon for 4 min and for 8 min at $38^{\circ}C$ and for 2 min and 4 min at $42^{\circ}C$, and for 1 min and 2 min at $45^{\circ}C$, along with control (for one min at $20^{\circ}C$). The red discoloration indices of basal part of chicon during sensory evaluation on the sixth day of storage under the storage temperature at $10^{\circ}C$ was lower at $42^{\circ}C$ for 2 min, $42^{\circ}C$ for 4 min and $45^{\circ}C$ for 1 min treatments. The color change value of the basal part in chicon measured by colorimeter showed that the lowest ${\Delta}a^*$ and ${\Delta}h$ were maintained in the basal part of chicon treated at $42^{\circ}C$ for 2 min. Whereas, color changes in $42^{\circ}C$ for 2 min and $45^{\circ}C$ for 1 min treatments were significantly low as compared with that of control. The contents of total phenolic compounds which are the substances that cause red discoloration of basal part in chicon were lowest at $42^{\circ}C$ for 2 min, $42^{\circ}C$ for 4 min and $45^{\circ}C$ for 1 min treatments. The activity of phenylalanine ammonia lyase (PAL) resposible for in the synthesis of phenolic substances was the least in $42^{\circ}C$ for 2 min treatment. Whereas, PAL activity of the chicons treated a t $42^{\circ}C$ for 2 min and at $45^{\circ}C$ for 1 min were significantly lower than that of control. However, red discoloration was progressed as similar level with that of control in the basal part of chicon at $45^{\circ}C$ for 2 min. The contents of total phenolic compounds and PAL activity in this treatment were not significantly different from those in control. The polyphenol oxidase (PPO) activity which causes red discoloration of cut tissues was low in all the treatments including $42^{\circ}C$ and $45^{\circ}C$ treatment at which no inhibition effects of the red discoloration of basal part of chicon were observed. When the correlation coefficient between each investigated index was tested, most of them showed high correlation except the PPO activity and particularly and the red discoloration index and sensory evaluation ${\Delta}h$ values, and PAL activity and total phenolic compounds content were $r=0.927^{**}$, and $r=0.942^{**}$, respectively.

• Archives of Pharmacal Research
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• v.21 no.5
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• pp.555-558
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• 1998

chondroitin sulfates were isolated from the mud snail. For the quantitative analysis of enzymatic digestion products of isolated chondroitin sulfates, strong anion exchange-high performance liquid chromatography (SAX-HPLC) was performed. by the action of chondroitinase ABC, three unsaturated disaccharides$ 2-acetamide-2-deoxy-3-O-({\beta}-D-gluco-4-enepyranosyluronic acid)-D-galactose $$({\Delta}Di-OS), $2-acetamide-2-deoxy-3-O-({\beta}-D-gluco-4-enepyranosyluronic acid)-6-O-sulfo-D-galactose ({\Delta}Di-6S) and 2-acetamide-2-deoxy-3-O-({\beta}-D-gluco-4-enepyranosyluronic acid)-4-O-sulfo-D-galactose ({\Delta}Di-4S)$ were produced from the mud snail chondroitin sulfates. The analysis showed that relative proportion of ${\Delta}Di-OS/{\Delta}Di-6S/{\Delta}Di-4S$ was 58.7/3.1/38.2. The immunomodulating activity of chondroitin sulfate was examined by cell proliferation assay and these results suggest that it might be a immunosuppressant.

• Journal of Sericultural and Entomological Science
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• v.37 no.1
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• pp.68-73
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• 1995

The toxic effect of Bacillus thuringiensis var, kurstaki $\delta$-endotoxin was determined in the midgut, fat body and Malpighian lobules from larvae of Hyphantria cunea using the au-toradiography and Western blot methods. Bt $\delta$-endotoxin crystals inhibited protein synthesis and elongation factor-2 activity of all tissues tested.

• Microbiology and Biotechnology Letters
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• v.21 no.5
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• pp.393-398
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• 1993

One strain of mosquitocidal Bacillus thuringiensis, H9B, was isolated from soil. The biochemical characteristics and flagella antigenicity of the strain H9B is similar to that of B. thuringiensis subsp. darmstadiensis. The delta-endotoxin of the strain H9B coincided with that of B. thuringiensis subsp. darmstadiensis strain 73E10-2 on agarose double immunodiffusion test. The delta-endotoxin of B. thuringiensis subsp. israelensis contains hemolysin fragment (28 kb) on SDS-PAGE when the delta-endotoxin was solubilized in alkali, while that of the strain H9B does not contain 28 kb protein.

• Bulletin of the Korean Chemical Society
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• v.31 no.4
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• pp.874-880
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• 2010

A series of 13- and 14-membered cyclic enkephalin analogs based on the moderately $\mu$ selective prototype compound Tyr-C[D-$A_2bu$-Gly-Phe-Leu] 8a were synthesized to investigate the structure-activity relationship. The modifications of sequence were mainly focused on two positions 3 and 5, critical for the selective recognition for $\mu$ and $\delta$ opioid receptors. The substitution of hydrophobic $Leu^5$ with hydrophilic $Asp^5$ derivatives led to Tyr-C[D-$A_2bu$-Gly-Phe-Asp(N-Me)] 7 and Tyr-C[D-Glu-Phe-gPhe-rAsp(O-Me)] 5, the peptides with a large affinity losses at both $\mu$ and $\delta$ receptors. The substitution of $Phe^3$ with $Gly^3$ led to Tyr-C[D-Glu-Gly-gPhe-rLeu] 3 and Tyr-C[D-Glu-Gly-gPhe-D-rLeu] 4, the peptides with large affinity losses at $\mu$ receptors, indicating the critical role of phenyl ring of $Phe^3$ for $\mu$ receptor affinities. One atom reduction of the ring size from 14-membered analogs Tyr-C[D-Glu-Phe-gPhe-(L and D)-rLeu] 6a, 6b to 13-membered analogs Tyr-C[D-Asp-Phe-gPhe-(L and D)-rLeu] 1, 2 reduced the affinity at both $\mu$ and $\delta$ receptors, but increased the potency in the nociceptive assay, indicating the ring constrain is attributed to high nociceptive potency of the analogs. For the influence of D- or L-chirality of $Leu^5$ on the receptor selectivity, regardless of chirality and ring size, all cyclic diastereomers displayed marked $\mu$ selectivity with low potencies at the $\delta$ receptor. The retro-inverso analogs display similar or more active at $\mu$ receptor, but less active at $\delta$ receptor than the parent analogs.