• Biotechnology and Bioprocess Engineering:BBE
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• 제8권2호
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• pp.59-63
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• 2003

The protein disulfide isomerase (PDI) reaction kinetics has been studied to evaluate its effect on the monoclonal antibody (Mab) refolding and assembly which accompanies disulfide bend formation. The MAb in vitro assembly experiments showed that the assembly rate of heavy and light chains can be greatly enhanced in the presence of PDI as compared to the rate of assembly obtained by the air-oxidation. The reassembly patterns of MAb in-termediates were identical for both with and without PDI, suggesting that the PDI does not determine the MAb assembly pathway, but rather facilitates the rate of MAb assembly by promoting PDI catalyzed disulfide bond formation. The effect of growth rate on PDI activities for MAb production has also been examined by using continuous culture system. The specific MAb productivity of hybridoma cells decreased as the growth rate increased. However, PDI activities were nearly constant fur a wide range of growth rates except very high growth rate, indicating that no direct correlation between PDI activity and specific MAb productivity exists.

• Asian-Australasian Journal of Animal Sciences
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• 제24권10호
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• pp.1417-1424
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• 2011

This study was conducted to assess the relation between threonine (Thr) oxidation rate and threonine efficiency on rat and chicken fed with graded levels of protein and threonine. The increase in threonine content from 0.28 to 0.72% in a diet containing 12.0% crude protein (CP) caused a gradual increase in threonine dehydrogenase (TDG) activity in rat liver. Similar, but more pronounced results were observed after 18.0% CP in the diet. Both protein levels in combination with the highest level of threonine supplementation increased liver TDG activity significantly, indicating enhanced threonine catabolism. Parameters of efficiency of threonine utilization calculated from parallel nitrogen balance studies decreased significantly and indicated threonine oversupply after a maximum of threonine supplementation. At the lower levels of threonine addition the efficiency of threonine utilization was not significantly changed. In the chicken liver up to 0.60% true digestible threonine (dThr) in the 18.5% CP diet produced no effect on the TDG activity. However, TDG activity in the liver was elevated by the diet containing 22.5% CP (0.60% dThr) and the efficiency of threonine utilization decreased, indicating the end of threonine limiting range. In conclusion, the in vitro TDG activity in the liver of rat and growing chicken has an indicator function for the dietary supply of threonine.

• 한국식품영양과학회지
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• 제35권7호
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• pp.903-907
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• 2006

전갱이 회수단백질은 동결저장 기간이 경과함에 따라 잔여지질의 산화생성물도 크게 증가하였으며, 백조기와 전갱이 회수단백질의 갈변도는 저장 90일 이후에 크게 증가하였다. 일반세균의 수는 전갱이 회수단백질이 백조기 회수단백질에 비하여 높았으나, 시판 수리미에서 검출되는 생균수와 거의 일치하였다. 백조기 회수단백질 가열 젤의 파괴강도, 변형 값 및 백색도 값은 저장 120일까지 큰 변화를 보이지 않은 반면, 120일동안 동결저장한 전갱이 회수단백질은 가열 젤을 형성하지 못했다. 가열 젤 형성능과 파괴강도 및 변형 값에 미루어 수산가공을 위한 중간소재로서 백조기와 전갱이 회수단백질의 동결저장 한계는 안정성을 고려할 때 각각 90일과 60일이 적당할 것으로 예측하였다.

• Animal Bioscience
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• 제35권1호
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• pp.22-28
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• 2022

Objective: Endoplasmic reticulum (ER) stress engages the unfolded protein response (UPR) that serves as an important mechanism for modulating hepatic fatty acid oxidation and lipogenesis. Chronic fasting in mice induced the UPR activation to regulate lipid metabolism. However, there is no direct evidence of whether negative energy balance (NEB) induces ER stress in the liver of cows. This study aimed to elucidate the relationship between the NEB attributed to feed deprivation and ER stress in bovine hepatocytes. Methods: Blood samples and liver biopsy tissues were collected from 6 non-lactating cows before and after their starvation for 48 h. The blood non-esterified fatty acids (NEFA), β-hydroxybutyric acid (BHBA) and glucose level were analyzed. Real-time quantitative polymerase chain reaction and Western blotting were used to explore the regulation of genes associated with UPR and lipid metabolism. Results: The starvation increased the plasma BHBA and NEFA levels and decreased the glucose level. Additionally, the starvation caused significant increases in the mRNA expression level of spliced X-box binding protein 1 (XBP1s) and the protein level of phosphorylated inositol-requiring kinase 1 alpha (p-IRE1α; an upstream protein of XBP1) in the liver. The mRNA expression levels of peroxisome proliferator-activated receptor alpha and its target fatty acid oxidation- and ketogenesis-related genes were significantly upregulated by the starvation-mediated NEB. Furthermore, we found that the mRNA expression levels of lipogenic genes were not significantly changed after starvation. Conclusion: These findings suggest that in the initial stage of NEB in dairy cows, the liver coordinates an adaptive response by activating the IRE1 arm of the UPR to enhance ketogenesis, thereby avoiding a fatty liver status.

• 대한한방내과학회지
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• 제29권1호
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• pp.200-218
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• 2008

Objectives : The purpose of this study was to investigate the effects of Injinchunggan-tang (Yinchenchinggan-tang) on DMN-induced liver damage by applying proteomics. Materials and Methods : Sprague-Dawley rats were used in this experiment and were divided into the normal group (normal saline), the control group (DMN) and the sample group (DMN+IJCGT). DMN was injected i.p. once a day three times a week for 3 weeks in the control group. Normal saline instead of DMN was administered to the normal group. In the sample group, Injinchunggan-tang (Yinchenchinggan-tang) extract was orally administered once a day for 10 days after DMN was induced. The livers of each group were processed and analyzed by histology, Western blot, $Oxyblot^{TM}$, CBB and 2-dimensional electrophoresis. Results : In the histological findings of the liver, IJCGT reduced collagen deposition and liver damage in DMN-induced hepatic fibrosis. IJCGT increased MMP-13 protein production assessed by western blot. Protein oxidation induced by DMN treatment was decreased by IJCGT. In the 2-dimensional electrophoresis finding, the level of the increased proteins induced by DMN treatment such as GRP 75, 58kDa glucose regulated protein and heat shock 70kDa protein 5 were decreased by IJCGT. IJCGT was considered to have the protective effects on hepatotoxicity induced by DMN. In the 2-dimensional electrophoresis finding, the level of increased oxidized proteins such as heat shock 70 protein, mitochondrial malonyltransferase, calreticulin precursor, actin, NADP-isocitrate dehydrogenase, ankyrin repeat and SOCS box protein 11 were decreased by IJCGT. IJCGT was considered to have protective effect on the protein production induced by DMN treatment. Conclusion : Injinchunggan-tang (Yinchenchinggan-tang) exerts an inhibitory effect against the fibrosis and protein oxidation induced by DMN treatment in the rat liver. IJCGT was considered to have protective effects on the hepatotoxicity and protein production induced by DMN treatment.

• Elastomers and Composites
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• 제54권2호
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• pp.110-117
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• 2019

The characterization of the ozone oxidation for raw natural rubber (NR) was investigated under controlled conditions through image and fourier transform infrared (FT-IR) analysis. The ozone oxidation was performed on a transparent thin film of raw NR coated on a KBr window in a dark chamber at $40^{\circ}C$ under low humidity conditions to completely exclude thermal, moisture, or light oxidation. The ozone concentration was set at 40 parts per hundred million (pphm). Before or after exposure to ozone, the image of the thin film for raw NR was observed at a right or tilted angle. FT-IR absorption spectra were measured in the transmission mode according to ozone exposure time. The ozone oxidation of NR was determined by the changes in the absorption peaks at 1736, 1715, 1697, and $833cm^{-1}$, which were assigned to an aldehyde group (-CHO), a ketone group (-COR), an inter-hydrogen bond between carbonyl group (-C=O) from an aldehyde or a ketone and an amide group (-CONH-) of protein, and a cis-methine group ($is-CCH_3=CH-$, respectively. During ozone exposure period, the results indicated that the formation of the carbonyl group of aldehyde or ketone was directly related to the decrement of the double bond of cis-1,4-polyisoprene. Only carbonyl compounds such as aldehydes or ketones seemed to be formed through chain scission by ozone. Long thin cracks with one orientation at regular intervals, which resulted in consecutive chain scission, were observed by image analysis. Therefore, one possible two-step mechanism for the formation of aldehyde and ketone was suggested.

• 한국환경농학회지
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• 제41권2호
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• pp.115-124
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• 2022

BACKGROUND: Methane is a major greenhouse gas attributed to global warming partly contributed by agricultural activities from ruminant fermentation and rice paddy fields. Methanotrophs are microorganisms that utilize methane. Their unique metabolic lifestyle is enabled by enzymes known as methane monooxygenases (MMOs) catalyzing the oxidation of methane to methanol. Rice absorbs, transports, and releases methane directly from soil water to its stems and the micropores and stomata of the plant epidermis. Methylobacterium species associated with rice are dependent on their host for metabolic substrates including methane. METHODS AND RESULTS: Methylobacterium spp. isolated from rice were evaluated for methane oxidation activities and screened for the presence of sMMO mmoC genes. Qualitatively, the soluble methane monooxygenase (sMMO) activities of the selected strains of Methylobacterium spp. were confirmed by the naphthalene oxidation assay. Quantitatively, the sMMO activity ranged from 41.3 to 159.4 nmol min^-1 mg of protein^-1. PCR-based amplification and sequencing confirmed the presence and identity of 314 bp size fragment of the mmoC gene showing over 97% similarity to the CBMB27 mmoC gene indicating that Methylobacterium strains belong to a similar group. CONCLUSION(S): Selected Methylobacterium spp. contained the sMMO mmoC gene and possessed methane oxidation activity. As the putative methane oxidizing strains were isolated from rice and have PGP properties, they could be used to simultaneously reduce paddy field methane emission and promote rice growth.

• 한국축산식품학회지
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• 제44권1호
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• pp.103-118
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• 2024

The aim of this study is to compare the quality characteristics of dry-cured loins with different levels of proteolysis and lipid oxidation and to investigate the relationship between these factors on quality characteristics. The dry-cured loins were divided into four groups [proteolytic index (PI) and 2-thiobarbituric acid reactive substances (TBARS) of high levels (HH), PI of high level and TBARS of low level (HL), PI of low level and TBARS of high level (LH), and PI and TBARS of low levels (LL)] based on the proteolysis index and TBARS. Moisture, protein, and fat content were all significantly influenced by proteolysis and lipid oxidation (p<0.05). The total fatty acid content in the high proteolysis groups (HH and HL) was significantly lower than that in the low proteolysis groups (LH and LL; p<0.05). For total free amino acid content, HH was the highest, and LL was the lowest (p<0.05). On the other hand, there was no significant difference between HL and LH (p>0.05). In the amount of total volatile compounds, there was no significant difference between HH and HL (p>0.05), but LH and LL significantly differed (p<0.05). In conclusion, proteolysis and lipid oxidation can influence the quality characteristics of dry-cured loin. Additionally, proteolysis might be as influential in generating volatile compounds as lipid oxidation.

• 생명과학회지
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• 제31권9호
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• pp.796-805
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• 2021

간 소포체(ER) 스트레스는 비알콜성지방간과 인슐린 저항성의 발달에 기여하고, unfolded protein response(UPR)의 구성요소는 지질 대사를 조절한다. 최근 연구에 따르면 ER 스트레스와 비정상적인 세포 지질 대사 사이의 연관성이 보고되었으며, 이 과정에서 지질 대사의 중심 조절자인 sterol regulatory element binding proteins(SREBPs)의 관련성이 확인되었다. 그러나 ER 스트레스 동안 지질 대사를 조절하는 SREBP의 정확한 역할과 비알콜성지방간에 대한 기여는 아직 밝혀지지 않았다. 본 연구에서 SREBP-1c 결핍은 UPR, 염증 및 지방산 산화 조절을 통해 ER 스트레스에 의해 유도된 비알콜성지방간으로부터 생쥐를 보호한다는 것을 보여준다. SREBP-1c는 inositol requiring kinase 1α (IRE1α) 발현을 직접적으로 조절하고 ER 스트레스에 의해 유도된 tumor necrosis factor-α의 활성화를 매개하여 peroxisome proliferator-activated receptor γ coactivator 1-α (PGC1α)의 감소와 그에 따른 지방산 산화의 장애를 유발한다. 그러나, SREBP-1c의 유전적 결핍은 이러한 현상을 보호하여 간 염증과 지방 축적을 완화시킨다. SREBP-1c 결핍이 ER 스트레스에 의해 유도된 염증 신호를 방지하는 메커니즘은 아직 밝혀지지 않았지만, SREBP-1c가 결핍된 Kupffer 세포에서 IRE1α 신호의 변화가 염증 신호에 관여할 수 있을 것으로 생각된다. 본 연구결과는 SREBP-1c가 ER 스트레스에 의해 유도된 비알콜성지방간에서 UPR 및 염증의 조절에 중요한 역할을 함을 시사한다.

• BMB Reports
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• 제42권9호
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• pp.568-573
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• 2009

Fatty acid oxidation (FAO) defects cause abnormal lipid accumulation in various tissues, which provides an opportunity to uncover novel genes that are involved in lipid metabolism. During a gene expression study in the riboflavin deficient induced FAO disorder in the chicken, we discovered the dramatic increase in mRNA levels of an uncharacterized gene, ANKRD9. No functions have been ascribed to ANKRD9 and its orthologs, although their sequences are well conserved among vertebrates. To provide insight into the function of ANKRD9, the expression of ANKRD9 mRNA in lipidperturbed paradigms was examined. The hepatic mRNA level of ANKRD9 was repressed by thyroid hormone ($T_3$) and fasting, elevated by re-feeding upon fasting. However, ANKRD9 mRNA level is reduced in response to apoptosis. Transient transfection assay with green fluorescent protein tagged- ANKRD9 showed that this protein is localized within the cytoplasm. These findings point to the possibility that ANKRD9 is involved in intracellular lipid accumulation.