• BMB Reports
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• 제41권9호
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• pp.635-639
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• 2008

Acrolein is a highly reactive by product of lipid peroxidation and individuals with neurodegenerative disorders have been shown to contain elevated concentrations of this molecule in the brain. In the present study, we examined the pattern of neurofilament-L (NF-L) modification elicited by acrolein. When NF-L was incubated with acrolein, protein aggregation occurred in a acrolein concentration-dependent manner. Exposure of NF-L to acrolein also led to the generation of protein carbonyl compounds. Through the addition of free radical scavengers we observed a significant decrease in acrolein-mediated NF-L aggregation. These results indicate that free radicals may be involved in the modification of NF-L by acrolein. In addition, dityrosine crosslink formation was observed in acrolein-mediated NF-L aggregates and these aggregates displayed thioflavin T reactivity, reminiscent of amyloid. This study suggests that acrolein-mediated NF-L aggregation might be closely related to oxidative reactions, thus these reactions may play a critical role in neuro-degenerative diseases.

• Bulletin of the Korean Chemical Society
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• 제29권9호
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• pp.1732-1736
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• 2008

The endogenous dipeptides, carnosine and related compounds, are the naturally occurring dipeptides with multiple neuroprotective properties. We have examined the protective effects of carnosine, homocarnosine and anserine on the aggregation of neurofilament-L (NF-L) induced by neurotoxin, acrolein. When NF-L was incubated with acrolein in the presence of carnosine, homocarnosine or anserine, protein aggregation was inhibited in a concentration-dependent manner. These compounds inhibited the formation of protein carbonyl compounds and dityrosine in acrolein-mediated NF-L aggregates. The aggregates of NF-L displayed thioflavin T reactivity, reminiscent of amyloid. This thioflavin T reactivity was inhibited by carnosine and related compounds. This effect was associated with decreased formation of oxidatively modified proteins. Our results suggested that carnosine and related compounds might have protective effects to brain proteins under pathophysiological conditions leading to degenerative damage such as neurodegenerative disorders.

• 한국축산식품학회지
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• 제43권2호
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• pp.305-318
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• 2023

This study investigated the protein digestibility of chicken breast and thigh in an in vitro digestion model to determine the better protein sources for the elderly in terms of bioavailability. For this purpose, the biochemical traits of raw muscles and the structural properties of myofibrillar proteins were monitored. The thigh had higher pH, 10% trichloroacetic acid-soluble α-amino groups, and protein carbonyl content than the breast (p<0.05). In the proximate composition, the thigh had higher crude fat and lower crude protein content than the breast (p<0.05). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of myofibrillar proteins showed noticeable differences in the band intensities of tropomyosin α-chain and myosin light chain-3 between the thigh and breast. The intrinsic tryptophan fluorescence intensity of myosin was lower in the thigh than in the breast (p<0.05). Moreover, circular dichroism spectroscopy of myosin revealed that the thigh had higher α-helical and lower β-sheet structures than the breast (p<0.05). The cooked muscles were then chopped and digested in the elderly digestion model. The thigh had more α-amino groups than the breast after both gastric and gastrointestinal digestion (p<0.05). SDS-PAGE analysis of the gastric digesta showed that more bands remained in the digesta of the breast than that of the thigh. The content of proteins less than 3 kDa in the gastrointestinal digesta was also higher in the thigh than in the breast (p<0.05). These results reveal that chicken thigh with higher in vitro protein digestibility is a more appropriate protein source for the elderly than chicken breast.

• 대한약리학회지
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• 제29권2호
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• pp.195-202
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• 1993

스트렙토조토신으로 당뇨를 유발시킨 쥐의 심근 근장그물에서 칼슘이동이 저하됨을 볼 수 있었다. 칼슘이동의 저하는 최대칼슘 uptake의 감소와 칼슘에 대한 affinity의 감소로 나타났다. 이러한 심근 근장그물의 기능저하가 나타나는 작용기전이 심근 근장그물 단백의 산화성 손상과 관계가 있는지를 살펴보았다. 당뇨쥐에서는 glycohemoglobin과 carbonyl group의 양이 현저히 증가됨을 볼 수 있었다. 한편으로 cyclic AMP 의존성 protein kinase의 catalytic subunit에 의한 phospholamban 인산화에 의해 심근 근장고물 칼슘이동의 증가를 보였고, 이 증가는 대조군에 비하여 당뇨군에서 훨씬 현저하게 나타났다. SDS-polyacrylamide를 이용한 전기영동후 autoradiogram을 통하여 확인한 phospholamban 인산화는 당뇨군에서 진한 band로 나타남이 확인되었다. 이상의 결과로 미루어 당뇨군의 심근 근장그물 기능저하는, 기초상태에서 아마도 심근내 저하된 norephinephrine 양으로 인하여 phospholamban 인산화 정도가 적으므로 근장그물 $Ca^{2+}-ATPase$ 억제가 나타남을 제시해 주며, 근장그물 단백의 산화성 손상도 당뇨성 심근질한을 일으킬 수 있는 또 다른 요인 중의 하나로 생각된다.

• 대한지역사회영양학회지
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• 제9권4호
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• pp.536-544
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• 2004

To evaluate the antioxidative effect of maengjong-juk (Phyllostachys pubescens) extract coated rice in vivo system, maengjong-juk extract coated rice diets were fed to C57BL/6 mice for 16 weeks. Plasma total antioxidative capacity, hepatic lipid peroxidation, protein oxidation, activities of antioxidative enzymes and total glutathione content were measured. Plasma total antioxidative capacity was elevated significantly in maengjong-juk extract diets supplemented group in a dose dependant manner. Hepatic TBARS contents were significantly decreased in maengjong-juk extract diets supplemented group compared to high cholesterol group. Maengjong-juk extract coated rice diets suppressed the protein oxidation significantly in liver. Activities of hepatic antioxidative enzymes such as total SOD, CuㆍZn-SOD, Mn-SOD, GSH-Px and catalase activities of maengjong-juk extract coated rice diets were significantly higher than those of high cholesterol diet. Total hepatic glutathione content was significantly increased by maengjong-juk extract coated rice diets administration. According to this study, numerous antioxidative materials and phytochemicals containing in maengjong-juk extracts appear to protect antioxidative systems in C57BL/6 mice fed bamboo extract coated rice diet. (Korean J Community Nutrition 9(4): 536∼544, 2004)

• Preventive Nutrition and Food Science
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• 제20권3호
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• pp.162-168
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• 2015

Lotus (Nelumbo nucifera Gaertn.) seed is widely used as a traditional medicine in countries of Asia. Among many functions of the lotus seed, one interesting activity is its skin protection from the sunlight and scar. In this study, we focused on the skin protective property of lotus seed tea against ultraviolet B (UVB) irradiation. Two groups of a hairless mouse model, water as control (water group) and lotus seed tea (LST group), were administrated a fluid drink water for six months. After 6 month of administration, UVB exposure was carried out to both groups for another 3 months. During and after the administration, the skin moisture content and the morphological and histopathological analyses through biopsy were carried out. Prior to UVB irradiation, no significant difference was discovered in the skin moisture content for the water group and LST group (P<0.05). However, drastic changes were observed after the UVB treatment. The LST group showed a clear evidence of skin protection compared to the control group (P<0.05). The moisture content, epidermal and horny layer thickness, and protein carbonyl values all revealed that the intake of the lotus seed tea enhanced protection against UVB exposure. As a result, the long-term intake of the lotus seed tea showed the effect of preventing loss of skin moisture, mitigating the formation of abnormal keratinocytes, and contributing to protein oxidation inhibition.

• 한국연초학회지
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• 제31권2호
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• pp.75-84
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• 2009

The objective of this study was to investigate the effect of nitrogen compounds such as protein on the chemical composition and toxicity of cigarette mainstream smoke. BSA protein was treated into the tobacco leaf of original 2R4F cigarette at 1~4 % level. The studies were performed which included a bacterial mutagenicity assay and a mammalian cell cytotoxicity assay for total particulate matter(TPM), and glutathione(GSH) consumption assay for gas/vapor phase(GVP) and determination of smoke chemical constitute. Cigarettes treated with protein were observed dose-dependent increase in yield of volatiles, semi-volatiles and aromatic amines compared with control cigarette. However, carbonyl compounds such as acrolein was lower than that of control cigarette when calculated on an equal TPM basis. The cytotoxicity of TPM obtained from the protein-added cigarettes was not different from that of control cigarette. However, the mutagenicity of the TPM from protein-treated cigarettes(1~4 %) was up to 10-27 % higher than that of control. On the other hand, toxicity of GVP from protein-treated cigarette(4 %) was significantly decreased compared with control cigarette. An overall assessment of our data suggests that nitrogen compounds such as protein should be important for the chemical composition and biological activity of cigarette mainstream smoke.

• 한국축산식품학회지
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• 제39권5호
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• pp.768-779
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• 2019

This study was performed to assess the comparison of the effects amongst butylated hydroxytoluene (BHT), clove extract (CE), and ascorbic acid (AA) as antioxidants on the oxidative stability and color values in fresh beef patties. The adding of BHT, AA, and CE to patties significantly restrained lipid oxidation, lowered hue angle as color value, and expanded redness and chroma values of fresh beef patties in comparison to the control (p<0.05). BHT and AA significantly led to impede the protein oxidation of patties by lowering carbonyl content (p<0.05). CE had no negative effect on protein oxidation. The antioxidant effects of BHT, AA, and CE were obviously manifested. Nonetheless, BHT, AA, and CE appeared to have insignificant difference of each other for lowering the protein oxidation at the end of storage. BHT and CE represented lowered lipid oxidation in comparison to AA. The antioxidant effects of BHT, AA, and CE on lipid oxidation were more marked than the effects on protein oxidation. Furthermore, CE as a natural antioxidant evinced the efficiency in oxidative stability and color stability in fresh beef patties. The study implied that CE could substitute the use of BHT and AA when making beef patties during storage.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2002년도 학술발표대회
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• pp.18-25
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• 2002

The pikromycin biosynthetic system in Streptomyces venezuleae is unique for its ability to produce two groups of antibiotics that include the 12-membered ring macrolides methymycin and neomethymycin, and the 14-membered ring macrolides narbomycin and pikromycin. The metabolic pathway also contains two post polyketide-modification enzymes, a glycosyltransferase and P450 hydroxylase that have unusually broad substrate specificities. In order to explore further the substrate flexibility of these enzymes a series of hybrid polyketide synthases were constructed and their metabolic products characterized. The plasmid-based replacement of the multifunctional protein subunits of the pikromycin PKS in S. venezuelae by the corresponding subunits from heterologous modular PKSs resulted in recombinant strains that produce both 12- and 14-membered ring macrolactones with predicted structural alterations. In all cases, novel macrolactones were produced and further modified by the DesVII glycosyltransferase and PikC hydroxylase leading to biologically active macrolide structures. These results demonstrate that hybrid PKSs in S. venezuelae can produce a multiplicity of new macrolactones that are modified further by the highly flexible DesVII glycosyltransferase and PikC hydroxylase tailoring enzymes. This work demonstrates the unique capacity of the S. venezuelae pikromycin pathway to expand the toolbox of combinatorial biosynthesis and to accelerate the creation of novel biologically active natural products. The polyketide backbone of rifamycin B is assembled through successive condensation and ${\beta}$-carbonyl processing of the extender units by the modular rifamycin PKS. The eighth module, in the RifD protein, contains nonfunctional DH domain and functional KR domain, which specify the reduction of the ${\beta}$-carbonyl group resulting in the C-21 bydroxyl of rifamycin B. A four amino acid substitution and one amino acid deletion were introduced in the putative NADPH binding motif in the proposed KR domain encoded by rifD. This strategy of mutation was based on the amino acid sequences of the corresponding motif of the KR domain of module 3 in the RifA protein, which is believed dysfunctional, so as to introduce a minimum alteration and retain the reading frame intact, yet ensure loss of function. The resulting strain produces linear polyketides, from tetraketide to octaketide, which are also produced by a rifD disrupted mutant as a consequence of premature termination of polyketide assembly. Much of the structural diversity within the polyketide superfamily of natural products is due to the ability of PKSs to vary the reduction level of every other alternate carbon atom in the backbone. Thus, the ability to introduce heterologous reductive segments such as ketoreductase (KR), dehydratase (DH), and enoylreductase (ER) into modules that naturally lack these activities would increase the power of the combinatorial biosynthetic toolbox. The dehydratase domain of module 7 of the rifamycin PKS, which is predicted to be nonfunctional in view of the sequence of the apparent active site, was replaced with its functional homolog from module 7 of rapamycin-producing polyketide synthase. The resulting mutant strain behaved like a rifC disrupted mutant, i.e., it accumulated the heptaketide intermediate and its precursors. This result points out a major difficulty we have encountered with all the Amycolatopsis mediterranei strain containing hybrid polyketide synthases: all the engineered strains prepared so far accumulate a plethora of products derived from the polyketide chain assembly intermediates as major products instead of just analogs of rifamycin B or its ansamycin precursors.

• 대한수의학회지
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• 제34권2호
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• pp.249-258
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• 1994

This study was carried out to investigate the inhibitory effects of vitamin E on the oxidative damage of cellular lipids and proteins in free radical reaction induced by $FeCl_3$, and ascorbic acid. In this experiment, a vitamin E treated rat group was administered with 100mg/kg body weight of $dl-{\alpha}-tocophery$ 1 acetate and an untreated rat group was administered with the same volume of corn oil. And then assays of malondialdehyde and carbonyl group in total homogenate, mitochondrial and microsomal fraction of rat liver were carried out at the scheduled time. The results obtained from this study were summarized as follows; 1. Lipid peroxidation levels in vitamin E administered rat liver cells were significantly (p<0.05) decreased at the intervals between 1 hour and 4 hours in liver homogenate, at all times except for 1 hour point in mitochondrial fraction, and also at the intervals between 0.5 hour and 3 hours in microsomal fraction compared with those of the control rat liver cell. 2. Protein oxidation levels in vitamin E administered rat liver cell were also significantly (p<0.05) decreased at the intervals between 1.5 hours and 4 hours in liver homogenate, at over 4 hours in liver mitochondrial fraction, and at the intervals between 0.5 hour and 3 hours in liver microsomal fraction compared with those of the control rat liver cells.