• Journal of Photoscience
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• 제9권2호
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• pp.55-58
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• 2002

The reaction center Dl protein of photosystem II is the target of photodamage by excess illumination. The Dl protein is damaged by reactive oxygen species generated by photochemical reactions and then degraded by specific proteolytic enzymes. We found that the Dl protein also cross-links with the surrounding polypeptides, such as D2 and CP43 in isolated thylakoids or photosystem II-enriched membranes from spinach under the illumination with strong visible light. The cross-linking was observed in spinach leaf discs as well when they were illuminated at higher temperature (40°C). It was also shown that the cross-linked products are digested efficiently by a protease(s) in the stroma. Thus the cross-linking/digestion processes of the Dl protein seem to comprise a new pathway in the turnover of the photodamaged Dl protein. It should be noted, however, that the cross-linked products of the Dl protein and CP43 induced by endogenous cationic radicals in the donor-side photoinhibition are resistant to proteolytic digestion. Accumulation of these cross-linked products in the thylakoids may lead to the decay of the function of chloroplasts and finally to the death of plant cells. Thus, we suggest that the quality control of photosystem II, especially removal of the cross-linked products of the Dl protein, is crucial for the survival of chloroplasts under the light stress.

• 분석과학
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• 제17권5호
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• pp.388-392
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• 2004

genomics의 정보해석이나 신경전달물질 또는 약의 전달체계에서 아주 중요한 역할을 담당하는 막단백질의 구조연구는 기존의 X-ray나 용액상 핵자기공명분광법으로 수행하기 어려우나 지방질 이분자층이나 여러분자층에서 움직이지 않게 정렬시킨 단백질시료를 이용하여 특이하게 고안된 home-built solid-state NMR probe를 이용하면 구조를 연구할 수 있다. 이 논문에서는 박테리오파지인 pf1의 growth, 분리, 정제 및 pf1에서의 coat protein의 분리, 정제과정과 최종적으로 분리 정제된 pf1의 coat protein의 인산지방질 이분자층에서의 구조를 고체상 핵자기공명 분광법을 이용하여 연구하고자 한다.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1997년도 춘계학술대회
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• pp.93-93
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• 1997

Analysis of protein is often frustrated by the inability to isolate large amounts of purified protein from a native source. To overcome this problem, fusion protein expression systems such as pGEX system have been widely used. Using pGEX system, the desired protein could be easily obtained in a large amount in E. coli, and then the fusion protein could be used for the study of the function of the given protein. To analyze and purify the GST fusion protein, anti-GST antibody could be used as one of the system of choice. However, the production and characterization of monoclonal anti-GST antibody has not been studied extensively yet. To produce monoclonal anti-GST antibody, GST was purified from E. coli transformed with pGEX-cs, one of the pGEX system and was used as an antigen. The monoclonal antibody was produced by fusion of the immunized spleen cells with SP2-0 myeloma cells. The antibody was characterized by ELISA, western blotting, etc. The monoclonal antibody produced in this study (mAb-GSTA) showed strong and specific immunoreactivity against not only GST but also GST-fusion proteins. Also, mAb-GSTA was successfully used for the immunoaffinity purification of the GST ${\beta}$-Rc.-third intracellular-loop fusion protein. The results of the present study suggest that mAb-GSTA may be used for the identification and purification of GST fusion proteins.

• Journal of Nutrition and Health
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• 제29권8호
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• pp.861-866
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• 1996

Tannins in plant foods and beverages may produce antinutritional or toxic effects although some proteins with high affinity for tannins seem to function as defense mechanism to tannin toxicity. Our objectives were to investigate of tea tannins, iron and protein and to evaluate the role of proteins in tannin effects on iron solubility. Iron solubility in vitro was measured using tea with and without proteins. Mixtures of tea, protein in varying concentrations(either gelatin or bovine serum albumin), and iron(eithe 10 or 50ug/mL) were prepared. Controls contained water in place of tea. Iron bioavailability was assessed by measuring iron solubility in the simulated gastric condition with pepsin digestion. Bound iron was removed by centrifugation and soluble in tea alone. When iron concentratin was 10ug/mL, addition of small amounts of protein to tea dramatically reduced iron solubility, but solubility of iron increased in the tea mixturea as the concentration of protein was increased. The percnetage of iron that precipitated was much greater at 10ug Fe/mL than the values at 50ug Fe/mL suggesting that the iron binding sites on the tea-protein complex was saturated. These results suggest that interactions of iron with tea tannins are influenced by the concentratins of protein and iron.

• 한국임상수의학회지
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• 제28권1호
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• pp.75-80
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• 2011

Proteomics is a useful approach to know protein expression, post-translational modification and protein function. We investigated the protein expression pattern and identity in pigs fed with the tissue culture medium waste after harvest of Korean wild ginseng (TCM-KWG) (Panax ginseng). Two groups (n = 30/group) of pigs were administered with 0 (control) and 16 ml/L (treatment) TCM-KWG through drinking water. After 4 weeks, we examined the protein expression pattern of longissimus dorsi muscle by Two-dimensional electrophoresis analysis. TCM-KWG treatment significantly increased two spot's density, and markedly reduced one spot's density in the muscles. We identified 3 proteins (heat shock protein 90-alpha, myosin binding protein and cofilin 2) by the ESI-MS/MS (Q-TOF2, Micromass). These results demonstrate that TCM-KWG treatment may play a protection role against physiological stress in pigs, like as increased heat shock protein 90-alpha.

• Rapid Communication in Photoscience
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• 제4권1호
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• pp.1-8
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• 2015

For understanding molecular mechanisms of photochemical reactions, in particular reactions of proteins with biological functions, it is important to elucidate both the initial reactions from the photoexcited states and the series of subsequent chemical reactions, e.g., conformation, intermolecular interactions (hydrogen bonding, hydrophobic interactions), and inter-protein interactions (oligomer formation, dissociation reactions). Although time-resolved detection of such dynamics is essential, these dynamics have been very difficult to track by traditional spectroscopic techniques. Here, relatively new approaches for probing the dynamics of protein photochemical reactions using time-resolved transient grating (TG) are reviewed. By using this method, a variety of spectrally silent dynamics can be detected and such data provide a valuable description about the reaction scheme. Herein, a blue light sensor protein TePixD is the exemplar. The initial photochemistry for TePixD occurs around the chromophore and is detected readily by light absorption, but subsequent reactions are spectrally silent. The TG experiments revealed conformational changes and changes in inter-protein interactions, which are essential for TePixD function. The TG experiments also showed the importance of fluctuations of the intermediates as the driving force of the reaction. This technique is complementary to optical absorption detection methods. The TG signal contains a variety of unique information, which is difficult to obtain by other methods. The advantages and methods for signal analyses are described in detail in this review.

• Archives of Pharmacal Research
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• 제22권3호
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• pp.267-273
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• 1999

In this study we examined the potential for the synergistic augmentation of the antitumor activity of inflammatory mouse peritoneal macrophages by stimulation with protein A combined with $IFN-\gamma$. The moderate augmentative effect induced by preincubation with protein A was demonstrated to be concentration-dependent, whereas IFN-, had a very low activating effect. Following preincubation with both protein A and $IFN-\gamma$, a marked enhancement of macrophage activity was noted. In addition, based on the utilization of neutralizing antibody to TNF-$\alpha$ or the inhibition of NO Production, TNF-$\alpha$ and NO were proven to be involved as mediators during the activation of tumoricidal macrophages by protein A in combination with $IFN-\gamma$. We also demonstrated that supernatants from macrophages treated with protein A plus $IFN-\gamma$ contained both TNF-$\alpha$ and NO at markedly increased levels. Thus, tumor cell lysis in the combined system was mediated via TNF-$\alpha$ or NO. These results demonstrate the synergistic effects on mouse pertioneal macrophage function of protein A in combination with $IFN-\gamma$ and suggest that combinations of such agents may serve as the basis for future in vivo immunotherapy.

• Journal of Nutrition and Health
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• 제29권10호
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• pp.1059-1071
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• 1996

This study was performed to investigate the effect of dietary protein level on renal senescence. Male rats of 337.8$\pm$5.7g body weight were underlateral nephrectomy or shamoperation. The rats were divided into high protein(40% casein), normal protein(15% casein) and low protein(8% casein)diets and fed experimental diets ad libitum for 24 weeks. The results are summarized as follows. There was a hypertophy of the remnant kidney of uninephrectomized rats of 40% or 15% protein group, coming up to the comparable weights of both kidneys of sham-operated rats. However, the hypertrophic effect was not seen in uninephrectomized rats of 8% protein group. Serum albumin was lower in uninephrectomized rats. With increasing dietary protein level blood urea nitrogen was increased, whereas, urinary urea nitrogen excretion was decreased. Urinary solute excretion was higher in uninephrectomized group than in sham-operated group. However, effect of dietary protein level on urinary solute excretion varied dpending on th solutes tested. GFR and urinary protein excretion, throughout experiment, increased with feeding period and with dietary protein level. Proteinuria was most severe in uninephrectomized rats fed 40% casein diet. Maximum urine concentration ability measured after dehydration was not different among the experimental groups. Light microscopic examination showed focal segmental glomerulosclerosis and mild increas of glomerular mesangial matrix in uninephrectomized rats fed 40% and 15% protein diet, however, which was not observed in uninephrectomized rats fed 8% protein diet and in sham-operated rats fed 40% diet. Immunofluorescence studies revealed segmental deposits of albumin in the mesangium and capillary loops in high protein and uninephrectomized groups. Minimal granular deposition of IgG was noted in the mesangium of all experimental groups. In conclusion, high protein intake accelerated deterioration of renal function and it was correlated with morphological change. Low protein intake was effective in preventing these changes.

• 한국정보통신학회논문지
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• 제22권1호
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• pp.26-32
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• 2018

단백질의 이차구조는 단백질의 진화, 구조, 기능을 연구하는데 중요한 정보이다. 단백질 서열 정보만을 이용하여 단백질의 이차 구조를 예측하는 분야에 심층 학습 방법들이 최근 들어 활발히 적용되고 있다. 이러한 방법에서 널리 사용되는 입력은 단백질 서열을 변환하여 만들어진 단백질 프로파일이다. 본 논문에서는 효과적인 단백질 프로파일을 얻기 위하여 단백질 서열 탐색 방법으로 PSI-BLAST와 더불어서 HHblits를 사용하였다. 단백질 프로파일의 구성에 사용되는 상동 단백질 서열을 결정하기 위한 유사도 문턱치와 상동 단백질 서열 정보를 반복적으로 사용하는 회수를 조절하였다. 합성곱 신경망과 순환 신경망을 사용하여 단백질 이차구조를 예측하였는데, 진화적 정보를 한번만 추가하여 만들어진 단백질 프로파일이 효과적이었다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권2호
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• pp.217-223
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• 2019

Objective: An experiment was conducted to investigate the effects of feed intake restriction during late pregnancy on the function, anti-oxidation capability and acute phase protein synthesis of ovine liver. Methods: Eighteen time-mated ewes with singleton fetuses were allocated to three groups: restricted group 1 (RG1, 0.18 MJ ME/kg $W^{0.75}$ d, n = 6), restricted group 2 (RG2, 0.33 MJ ME/kg $W^{0.75}$ d), n = 6) and a control group (CG, ad libitum, 0.67 MJ ME/kg $W^{0.75}$ d, n = 6). The feed restriction period was from 90 days to 140 days of pregnancy. Results: The ewe's body weight, liver weights, water, and protein content of liver in the restricted groups were reduced compared with the CG group (p<0.05), but the liver fat contents in the RG1 group were higher than those of the CG group (p<0.05). The increased hepatic collagen fibers and reticular fibers were observed in the restricted groups with the reduction of energy intake. The concentrations of nonesterified free fatty acids in the RG1 and RG2 groups were higher than those of the CG group with the reduction of energy intake (p<0.05), but there were decreased concentrations of lipoprotein lipase and hepatic lipase in both restricted groups compared with the CG group (p<0.05). In addition, the increased concentrations of ${\beta}$-hydroxybutyric acid, triglycerides, malondialdehyde, total antioxidant capacity and activities of superoxide dismutase activity and catalase were found in the RG1 group, and the concentrations of cholinesterase in the RG1 group were reduced compared with the CG group (p<0.05). For the concentrations of acute phase proteins, the C-reactive protein (CRP) in the RG1 group were reduced compared with the CG group, but there were no differences in haptoglobin relative to the controls (p>0.05). Conclusion: The fat accumulation, increased hepatic fibrosis, antioxidant imbalance and modified synthesis of acute phase proteins were induced in ewe's liver by maternal malnutrition during late pregnancy, which were detrimental for liver function to accommodate pregnancy.