• 한국자기공명학회논문지
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• 제19권3호
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• pp.99-105
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• 2015

Hsp33 is a prokaryotic molecular chaperon that exerts a holdase activity upon response to an oxidative stress at raised temperature. In particular, intramolecular disulfide bond formation between the four conserved cysteines that bind a zinc ion in reduced state is known to be critically associated with the redox sensing. Here we report the backbone NMR assignment results of the half-oxidized Hsp33, where only two of the four cysteines form an intramolecular disulfide bond. Almost all of the resolved peaks could be unambiguously assigned, although the total assignments extent reached just about 50%. Majority of the missing assignments could be attributed to a significant spectral collapse, largely due to the oxidation-induced unfolding of the C-terminal redox-switch domain. These results support two previous suggestions: conformational change in the first oxidation step is localized mainly in the C-terminal zinc-binding domain, and the half-oxidized form would be still inactive. However, some additional regions appeared to be potentially changed from the reduced state, which suggest that the half-oxidized conformation would be an intermediate state that is more labile to heat and/or further oxidation.

• 한방안이비인후피부과학회지
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• 제20권1호통권32호
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• pp.1-15
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• 2007

Objectives : RVC has long been used for a useful natural agent ameliorating inflammation related symptoms in the folk medicine recipe. This study was performed to investigate effects of RVC on the inflammation and oxidation in RAW 264.7 cells. Methods : The RVC was extracted with 80% ethanol and sequentially partitioned with solvents in order to increase polarity. With the various fractions, we determined the activities on the inflammation and oxidation in RAW 264.7 cells. Results : 1. Among the various solvent extracts of RVC, the butanol fraction showed the most powerful inhibitory ability against nitric oxide (NO) production in lipopolysaccharide (LPS)-induced RAW 264.7 cells without affecting cell viability. 2. Butanol fraction showed a oxidation inhibition effect by decreasing the DPPH and OH radicals. 3. Butanol fraction exhibited the inhibitory avilities against iNOS and COX-2. 4. Reverse transcriptase polymerase chain reaction (RT-PCR) and Westem blotting analysis revealed that the BuOH fraction provided a primary inhibitor of the iNOS protein and mRNA expression in LPS-induced RAW 264.7 cells. Among the up-regulater molecules of iNOS and COX-2, the BuOh fraction of RVC was shown the inhibitory activity of phoshporylation of c-Jun N-terminal kinase (JNK) 1/2 and threonine protein kinase (AKT), the one of the MAPKs pathway. Conclusion : Thus, the present study suggests that the response of a component of the BuOH fraction to NO generation via iNOS expression provide a important clue to elucidate anti-inflammatory and anti-oxidation mechanism of RVC.

• Preventive Nutrition and Food Science
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• 제1권1호
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• pp.134-142
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• 1996

Diabetes carries an increased risk of atherosclerotic disease that is not fully explained by known car-diovascular risk factors. There is accumulating evidence that advanced glycation of structural proteins, and oxidation and glycation of circulating lipoproteins, are implicated in the pathogenesis of diabetic ather-osclerosis. Reactions involving glycation and oxidation of proteins and lipids are believed to contribute to atherogenesis. Glycation, the nonenzymatic binding of glucose to protein molecules, can increase the ather-ogenic potential of certain plasma constituents, including low density lipoptotein(LDL). Glycation of LDL is significant increased in diabetic patients compared with normal subjects, even in the presence of good glycemic control. Metabolic abnormalities associated with glycation of LDL include diminished recognition of LDL by the classic LDL receptor; increased covalent binding of LDL in vessel walls ; enhanced uptake of LDL by the macrophages, thus stimulating foam cell formation ; increased platelet aggregation; formation of LDL-immune complexes ; and generation of oxygen free radicals, resulting on oxidative damage to both the lipid and protein components of LDL and to any nearby macromolecules. Oxidized lipoproteins are characterzied by cytotoxicity, potent stimulation of foam cell formation by macrophages, and procoagulant effects. Combined glycation and oxidation, "glycoxidation" occurs when oxidative reactions affect the initial products of glycation, and results in irreversible structural alterations of proteins. Glycoxidation is of greatest significance in long lived proteins such as collagen. In these proteins, glycoxidation products, believed to be atherogenic, accumulate with advancing age : in diabetes, their rate of accumulate is accelerated. Inhibition of glycation, oxidation and glycoxidation may form the basis of future antiaterogenic strategies in both diabetic and nondiabetic individuals.dividuals.

• 한국식품영양과학회지
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• 제31권1호
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• pp.104-108
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• 2002

우리밀과 수입밀의 PBS 추출물의 LDL 산화 억제 효과를 비교하였고, 고콜레스테롤혈증 유발 가토의 조직중 지질과 산화 및 대동맥의 조직 변화를 측정함으로써 우리밀이 동맥경화의 진행 양상 변화에 어떠한 효과가 있는지 검토하였다. 밀 추출물의 LDL 산화 억제 효과는 우리밀과 수입밀이 각각 62.5%, 52.8%로 나타나 우리밀 추출물의 LDL 산화 억제 효과가 수입밀에 비해 약간 높았다. 고콜레스테롤혈증 유발 가토의 간장중 TBARS 함량은 수입밀보다 우리밀 섭취시 낮게 나타나 우리밀이 지질 과산화를 억제하는데 효과가 있는 것으로 나타났지만, 신장에서의 억제 효능은 비슷한 것으로 나타났다. 대동맥의 석회 침착 발생율은 대조군에 비해 낮았지만 우리밀과 수입밀의 섭취로 인한 뚜렷한 차이는 입증되지 않았다. 이상의 결과로 추출물의 LDL 산화 억제 효과가 입증되었으며, 우리밀 섭취가 콜레스테롤 섭취로 인한 간장중 지질 과산화적 손상을 완화시키는데 기여함을 알 수 있었지만 우리밀과 수입밀 섭취로 인한 동맥경화 예방효과에 대한 뚜렷한 차이는 나타나지 않았다.

• 한국식품과학회지
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• 제33권1호
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• pp.1-6
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• 2001

수용성 단백질을 첨가한 유화물을 형광 조명하에서 $5^{\circ}C$에서 8일간 저장하였을 때 POV(Peroxide value) 값의 변화를 측정한 결과 저장 초기에 유의적인 증가를 나타냈고 TBA(Thiobarbituric acid) 값의 변화에서도 저장 4일까지 상당량의 카르보닐 화합물이 발생하는 것으로 나타나서 일반적인 지방의 자동산화와는 다른 양상을 보였고 대두유 같은 유지에서 저장 초기에 나타나는 변향의 발생과 비슷한 결과를 나타냈다. 이러한 원인으로는 육색소인 myoglobin에 의한 산화로 사료되며 superoxide anion보다는 일중항 산소에 의한 산화일 가능성이 높은 것으로 사료된다. 빛을 차단하였을 때에도 전체적인 양상을 비슷했지만 산화생성물의 생성량이 빛을 쪼였을 때보다 약간 적었고 일중항 산소의 효과도 두드러지지 않았으며 유화물 제조과정 중에 생성된 일중항 산소가 저장 초기의 변향에 관여하였을 것으로 추정된다. 수용성 단백질을 첨가하지 않은 경우에는 과산화물의 생성량이 지속적인 증가를 나타내서 수용성 단백질 처리구와 차이를 보였는데 과산화물의 분해속도가 수용성 단백질 처리구에 비해 작은 것으로 사료되며 특히 저장 4일 이후에 카르보닐 화합물의 생성속도가 줄어드는 것으로 나타났다. 저장 중에 일중항 산소의 발생 가능성이 있는 것으로 나타났으나 대두유의 탈색과정에서 잔존하였을 식물성 감광체가 원인일 것으로 추정된다. 빛을 차단하였을 때에는 저장 초기의 산화생성물 발생량이 빛을 쪼였을 때보다 미미했고 소거제 처리에 대한 효과도 드러나지 않아서 지질의 산화에 대한 빛의 촉진효과를 나타내는 결과라고 사료된다.

• 생명과학회지
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• 제18권1호
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• pp.84-90
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• 2008

충청남도 병천면 일대의 6곳의 토양시료를 채취하여 망간을 산화하는 균주들을 순수분리 하고, 이 중 망간 산화능이 가장 우수한 한 균주를 최종 선별하여 본 실험에 사용하였다. 최종 선별된 균주의 생리, 생화학적 특성을 조사하고, 16S rRNA 염기 서열분석 등을 통하여 동정한 결과 최종 선별된 균주는 Pseudomonas sp. MN5로 확인되었다. Pseudomonas sp. MN5은 fructose와 maltose를 제외한 다양한 당을 이용하지 못하였으며, 항생제인 kanamycin, chloramphenicol, streptomycin 그리고 tetracycline에는 높은 감수성을 보이고, 리튬, 망간, 바륨과 같은 중금속에 대해서는 mg/ml 단위의 높은 내성을 나타냈다. 그리고 Pseudomonas sp. MN5의 망간산화 최적 pH는 7.5이고, 망간산화 활성이 proteinase K와 가열처리를 한 시료에서 저해되었다. Pseudomonas sp. MN5가 생성하는 망간산화 단백질을 ammonium sulfate precipitation, HiTrap Q FF ion exchange chromatography 그리고 G3000sw $_{XL}$ gel filtration chromatography를 통해서 정제한 결과, 15 kDa, 46.7 kDa 그리고 63.5 kDa의 세종류의 manganese oxidizing protein가 확인되었고, 내부서 열과 N-말단 서열 분석 결과 Pseudomonas sp. MN5가 생성하는 망간산화 단백질은 외막의 porin 단백질인 것으로 추정되었다.

• 자연과학논문집
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• 제17권1호
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• pp.13-29
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• 2006

산화-환원 활성 단백질중에 하나인 설피레독신과의 결합 단백질을 효모 Two-hybrid 기법을 이용하여 탐색한 결과, 알파-만노시다제가 설피레독신과 특이적으로 결합함을 밝혔다. 알파-만노시다제는 D-만노스 당을 비환원성 말단으로부터 유리시키는 가수분해 효소로서, 세포 원형질에 다량체 형태로 존재한다. 본 연구에서는 설피레독신과 알파-만노시다제간의 단백질결합을 설피레독신의 새로운 생리기능 관점에서 토의했다.

• Nutrition Research and Practice
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• 제2권3호
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• pp.158-164
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• 2008

This study investigated that the antioxidative effect of freeze-dried cranberry powder against protein and lipid oxidation and ameliorative effect of serum lipid profile in rat fed atherogenic diet. Six weeks old male Sprague-Dawley rats were divided into the following four groups: normal diet group with 5% com oil(control), atherogenic diet group with 5% com oil, 10% lard, 1% cholesterol, and 0.5% sodium cholate(HFC), atherogenic plus 2% cranberry powder diet group(HFC+C2), and atherogenic plus 5% cranberry powder diet group(HFC+C5), and respective diet and water were fed daily for 6 weeks. After the experimental period, the serum lipid profile, such as total cholesterol, HDL-cholesterol, LDL-cholesterol, and triglyceride, ferric reducing ability of plasma(FRAP), plasma phenolics content, superoxide dismutase(SOD) activity, serum protein carbonyl and thiobarbituric acid reactive substances(TBARS) levels were examined. Total phenolic compound and total flavonoid levels in freeze-dried cranberry powder were 9.94 mg/g and 8.12 mg/g, respectively. Serum total cholesterol and LDL-cholesterol levels were not significantly different for cranberry powder treatment, but serum HDL-cholesterol level was significantly increased in HFC+C5 group compared with HFC group. Plasma FRAP value tended to be increased by cranberry powder treatment though there was no significant difference. Plasma total phenol concentrations and SOD activities were not significantly different among all groups. Serum protein carbonyl and TBARS levels were significantly decreased in HFC+C5 group compared with HFC group. Overall results suggested that freeze-dried cranberry powder might have the serum lipid improving effect, as well as anti oxidative effect demonstrated by its protective effect against protein and lipid oxidation.

• 한국수산과학회지
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• 제16권2호
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• pp.117-124
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• 1983

Qualify changes of the precooked frozen sardine (Sardinops melanosticta) during frozen storage were investigated by measuring extractable protein, expressible drip, available lysine and lipid oxidation as peroxide value. Fresh sardine was dressed, washed in chilled water, cooked in boiling water to have $55^{\circ}C\;and\;70^{\circ}$ at the center of the body, frozen at $-40^{\circ}C$, and finally stored at $-20^{\circ}C$ for 84 days. The quality factor mentioned above were determined in both ordinary and dark muscle at 14 day intervals through the period of storage. When cooked at $70^{\circ}C$, the changes in expressible drip were less than that of raw and the one cooked at $55^{\circ}C$. In observation of the extractability of muscle protein, no great change in extractable sarcoplasmic protein was observed, the extractable myofibrillar protein, however, showed a tendency to decrease during the period of frozen storage, accompanying the increase of the alkali-soluble protein. That was more excessive in ordinary muscle than dark muscle. Lipid oxidation of dark muscle was faster than that of ordinary muscle. Acid value was not changed, and peroxide value of the samples cooked at $70^{\circ}C\;and\;55^{\circ}$ was higher than that of raw at the early stage of the storage, after 40-50 day storage, it became lower than that of raw muscle.

• Journal of Photoscience
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• 제9권2호
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• pp.138-141
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• 2002

A photo-labile compound which is bioinactive but, upon irradiation with light, yields bioactive species is called as "caged compound". Photolysis of caged compounds generating bioactive species, has become a general method to produce a desired amounts of bioactive species in the specific time interval at the desired place or area of the target biological systems. For this purpose, we designed and synthesized caged hydroxyl radical., "Photo-Fenton Reagent" NP-IIl. NP-IIl has a strong absorption maximum at 377 nm and yields hydroxyl radicals upon UV light irradiation. The antioxidant activity of the ${\alpha}$ -lipoic acid and other naturally occurring compounds has been examined by using NP-IIl as a molecular probe. For example, upon photoirradiation of NP-lII with BSA or apolipoprotein of human low density (LDL), the significant oxidative modifications were observed in both cases. The oxidation was completely suppressed in the presence of ${\alpha}$-lipoic acid, which clearly demonstrates the strong hydroxyl radical scavenging activity of ${\alpha}$-lipoic acid. Other applications of NP-lII will also be described