• Biotechnology and Bioprocess Engineering:BBE
• /
• v.9 no.3
• /
• pp.223-228
• /
• 2004

Agricultural waste products, beech wood and walnut shells, were hydrolyzed at 40$^{\circ}C$ using mixed crude enzymes produced by Penicillium sp. AHT-1 and Rhizomucor pusillus HHT-1. D-xylose, 4.1 g and 15.1 g was produced from the hydrolysis of 100 g of beech wood and walnut shells, respectively. For xylitol production, Candida tropicalis IFO0618 and the waste product hydrolyzed solutions were used. The effects on xylitol production, of adding glucose as a NADPH source, D-xylose and yeast extract, were examined. Finally, a 50% yield of xylitol was obtained by using the beech wood hydrolyzed solution with the addition of 1% yeast extract and 1% glucose at an initial concentration.

• Journal of Haehwa Medicine
• /
• v.8 no.1
• /
• pp.643-657
• /
• 1999

Through observing effect of BOPEASAN(BPT) on an aging white rat's metabolic enzyme system, the following conclusions were addressed 1. The quantity of the lipid peroxide in lung of was decreased meaningfully in all of experimental subject groups, relatively to counterpart groups. 2. Cytochrome P-450, Cytochrome b5, NADPH-Cytochrome P45, was decreased meaningfully in the experimental subject groups B,C and D. 3. superoxide dismutase, catarase, grutathione peroxidase, was increased meaningfully in the experimental subject groups B.C and D. 4. glutathione, glutathione S-transferase, glutathione redutase, ${\gamma}$-Glutamylcytein synthetase, had no meaningful change in the experimental subject groups. Regarding the above conclusions, the Bopeasan was affecting positively on both lipid peroxide a nd the enzyme system, as well as it has efficacy of suppressing the phenomena of aging, Therefore, the Bopeasan is, hereafter, expected to be applied clinically.

• Journal of Microbiology and Biotechnology
• /
• v.13 no.4
• /
• pp.613-619
• /
• 2003

The polyketide backbone of rifamycin B is assembled by the type I rifamycin polyketide synthase (PKS) encoded by the rifA-rifE genes. In order to produce novel analogs of rifamycin via engineering of the PKS genes, inactivation of the ${\beta}-ketoacyl:acyl$ carrier protein reductase (KR) domain in module 8 of rifD, by site-specific mutagenesis of the NADPH binding site, was attempted. Module 8 contains a nonfunctional dehydratase (DH) domain and a functional KR domain that is involved in the reduction of the ${\beta}-carbonyl$ group, resulting in the C-21 hydroxyl of rifamycin B. This mutant strain produced linear polyketides, from tetraketide to octaketide, which were also produced by a rifD-disruption mutant as a consequence of premature termination of the polyketide assembly. Another attempt to replace the DH domain of module 7, which has been considered nonfunctional, with a functional homolog derived from module 7 of rapamycin-producing PKS also resulted in the production of linear polyketides, including the heptaketide intermediate and its precursors. Premature release of the carbon chain assembly intermediates is an unusual property of the rifamycin PKS. that is not seen in other PKSs such as the erythromycin PKS.

• Biomolecules & Therapeutics
• /
• v.25 no.4
• /
• pp.417-426
• /
• 2017

4-O-methylhonokiol, a neolignan compound from Magnolia Officinalis, has been reported to have various biological activities including hair growth promoting effect. However, although transforming growth factor-${\beta}$ (TGF-${\beta}$) signal pathway has an essential role in the regression induction of hair growth, the effect of 4-O-methylhonokiol on the TGF-${\beta}$ signal pathway has not yet been elucidated. We thus examined the effect of 4-O-methylhonokiol on TGF-${\beta}$-induced canonical and noncanonical pathways in HaCaT human keratinocytes. When HaCaT cells were pretreated with 4-O-methylhonokiol, TGF-${\beta}1$-induced G1/G0 phase arrest and TGF-${\beta}1$-induced p21 expression were decreased. Moreover, 4-O-methylhonokiol inhibited nuclear translocation of Smad2/3, Smad4 and Sp1 in TGF-${\beta}1$-induced canonical pathway. We observed that ERK phosphorylation by TGF-${\beta}1$ was significantly attenuated by treatment with 4-O-methylhonokiol. 4-O-methylhonokiol inhibited TGF-${\beta}1$-induced reactive oxygen species (ROS) production and reduced the increase of NADPH oxidase 4 (NOX4) mRNA level in TGF-${\beta}1$-induced noncanonical pathway. These results indicate that 4-O-methylhonokiol could inhibit TGF-${\beta}1$-induced cell cycle arrest through inhibition of canonical and noncanonical pathways in human keratinocyte HaCaT cell and that 4-O-methylhonokiol might have protective action on TGF-${\beta}1$-induced cell cycle arrest.

• Toxicological Research
• /
• v.21 no.4
• /
• pp.291-295
• /
• 2005

To define the effect of silica on the stimulator of signaling pathway, we studied the phospholipase D (PLD) activity in the Rat2 fibroblasts. Silica stimulated the accumulation of labeled $[^3H]$ phosphatidylethanol$([^3H]\;PEt)$ in a time- and concentration-dependent manner. This Silicainduced PLD activity was partially attenuated by the pretreatment with U73122 (phospholipase C inhibitor), genistein (protein tyrosine kinase inhibitor), PD 98056 (MEK inhibitor) and mepacrine (phospholipase $A_2$ inhibitor). But, sphingosine (protein kinase C inhibitor) and DPI (NADPH reductase inhibitor) had not effect the PLD activity. Silica also increased the PLD activity about four fold, which imply that the PLD activity is more influenced by the mobilization of PLD than other signaling mediators. The PLD activity also partially inhibited calcium chelator EGTA or/and BAPTA/AM compared to silica. Finally, we concluded that a silica-stimulated phospholipase D activity is present in the Rat2 fibroblasts and is modulated by combination of various signaling mediators.

• Journal of Preventive Medicine and Public Health
• /
• v.32 no.1
• /
• pp.88-94
• /
• 1999

Objectives. In order to gain a better understanding of the mechanism of DMF toxicity, recent studies have focused on hepatic drug metabolizing enzymes. In this study, we investigated the effects of DMF on the induction of P450 and the activities of other related enzymes in rat liver microsomes. Methods. DMF was administered to male Sprague Daweley rats by intraperitoneal injection at 0(control), 450(D1), 900(D2), 1,800(D3) mg DMF/kg body weight in olive oil once a day for three days. Hepatic P450 was measured by method of Omura and Sato. We evaluated selective assays for the three drug metabolizing cytochrome P450 isoenzymes 1A1, 2B1 and 2E1. Results. The content of microsomal protein, P450 and b5 were tended to be decreased in DMF treated group, but they were not statistically significant. The activity of NADPH-cytochrome P450 reductase was significantly increased dose dependently(p<0.01), but the activity of NADH-b5 reductase was decreased in the treated group(p<0.01). The activities of PROD and EROD were not significant between control and treated group. The activities of pNPH in the DMF treated groups were higher than that of the control group(p<0.01). When Western immunoblottings were carried out utilizing three monoclonal antibodies which were specific against P4501A1/1, P4502B1/2 and P4502E1, the strong density band corresponding to P4502E1 was observed with the microsomes obtained from the rats treated with DMF. But there were no significant increased in the P4501A1/2 and P4502B1/2 band densities in immunoblotting. Conclusions. These result suggested that P4502E1 was inducible by DMF and P4502E1 isozyme might be responsible for the hydroxylation of DMF to HMMF.

• Microbiology and Biotechnology Letters
• /
• v.45 no.1
• /
• pp.81-86
• /
• 2017

Alignment of 967 reference sequences of the typical 2-Cys peroxiredoxin family of proteins revealed that 10 amino acids were conserved, with over 99% identity. To investigate whether the conserved aspartic acid residues and serine residue affect the peroxidase and chaperone activity of the protein, we prepared yeast TSA1 mutant proteins in which aspartic acids at positions 75 and 103 were replaced by valine or asparagine, and serine at position 73 was replaced by alanine. By non-reducing SDS-PAGE, TSA1 and the S73A, D75V and D75N mutants were detected in dimeric form, whereas the D103V and D103N mutants were detected in various forms, ranging from high molecular-weight to monomeric. Compared with wild type TSA1, the D75N mutant exhibited 50% thioredoxin peroxidase activity, and the S73A and D75V mutants showed 25% activity. However, the D103V and D103N mutants showed no peroxidase activity. All proteins, except for the D103V and D103N mutants, exhibited chaperone activity at $43^{\circ}C$. Our results suggest that the two conserved aspartic acid residues and serine residue of TSA1 play important roles in its thioredoxin peroxidase activity, and D103 plays a critical role in its chaperone activity.

• BMB Reports
• /
• v.32 no.4
• /
• pp.385-392
• /
• 1999

The $NAD^+$-specific activity of a dual coenzyme-specific isocitrate dehydrogenase (IDH; EC 1.1.1.41) from the primitive fungus Pythium ultimum was investigated to elucidate the regulatory factors that may influence the intracellular distribution of carbon and the availability of intermediates, e.g. citrate, for fatty acid synthesis. Inhibition of $NAD^+$-IDH activity by diphospho- and triphosphonucleotides (ATP, ADP, and GTP) reflected the sensitivity of this enzyme to cellular energy charge even though monophosphonucleotides (AMP and GMP) had little effect on activity. NADPH, but not NADH, substantially inhibited $NAD^+$-IDH activity, showing noncompetitive inhibition with isocitrate. Oxalacetate and ${\alpha}$-ketoglutarate showed competitive inhibition with isocitrate, while citrate and cis-aconitate showed mixed-noncompetitive inhibition with isocitrate. Inhibition by these substances ranged from 29 to 46% at 10 mM. The inhibitory effect of oxalacetate was increased synergistically by glyoxylate, which alone caused 31% uncompetitive inhibition at 10 mM, and a mixture of the two substances at 1 mM each showed 98% inhibition of $NAD^+$-IDH activity. The regulation of $NAD^+$-IDH in Pythium ultimum seems to be a complex process involving mitochondrial metabolites. The addition of glyoxylate (3 mM) and oxalacetate (3 mM) to the culture medium resulted in the production of 49% more lipid by P. ultimum.

• Journal of Acupuncture Research
• /
• v.23 no.3
• /
• pp.215-229
• /
• 2006

목적 : 당귀는 전통적으로 학습과 기억능력 증진 및 각종 질병치료에 우수한 효과가 있는 것으로 알려져있다. 본 연구에서는 이러한 인삼약침이 소음스트레스가 유발된 태아쥐의 해마 및 시상하부에서 nitric oxide synthase에 미치는 영향을 관찰하였다. 방법 : 당귀약침이 소음스트레스에 미치는 영향을 연구하기 위하여 태아기에 소음스트레스를 유발하고 생후 4주후 7일간 당귀약침을 투여한 후 NADPH-d 조직화학법을 시행하였다. 결과 : 1. 소음스트레스는 태아쥐의 해마 및 시상하부에서 NOS 발현이 유의하게 증가하였다. 2. 당귀약침은 해마 CAI에서만 소음스트레스에 의해서 증가된 NOS 발현을 유의하게 억제하였다. 3. 당귀약침은 시상하부 PVN, DMH 및 LHA에서 소음스트레스에 의해서 증가된 NOS 발현을 유의하게 억제하였다. 결론 : 본 연구를 통하여 당귀약침이 소음스트레스가 유발된 태아쥐의 해마 및 시상하부에서 증가된 NOS 발현을 유의하게 억제시켜 태아의 스트레스 자극에 당귀약침치료가 유의한 효과가 있음을 확인하였다.

• Journal of Microbiology and Biotechnology
• /
• v.21 no.2
• /
• pp.136-146
• /
• 2011

This study provides first-hand proteomic data on the survival strategy of Anabaena sp. PCC 7120 when subjected to long-term iron-starvation conditions. 2D-gel electrophoresis followed by MALDI-TOF/MS analysis of iron-deficient Anabaena revealed significant and reproducible alterations in ten proteins, of which six are associated with photosynthesis and respiration, three with the antioxidative defense system, and the last, hypothetical protein all1861, conceivably connected with iron homeostasis. Iron-starved Anabaena registered a reduction in growth, photosynthetic pigments, PSI, PSII, whole-chain electron transport, carbon and nitrogen fixation, and ATP and NADPH content. The kinetics of hypothetical protein all1861 expression, with no change in expression until day 3, maximum expression on the $7^{th}$ day, and a decline in expression from the $15^{th}$ day onward, coupled with in silico analysis, suggested its role in iron sequestration and homeostasis. Interestingly, the up-regulated FBP-aldolase, Mn/Fe-SOD, and all1861 all appear to assist the survival of Anabeana subjected to iron-starvation conditions. Furthermore, the $N_2$-fixation capabilities of the iron-starved Anabaena encourage us to recommend its application as a biofertilizer, particularly in iron-limited paddy soils.