• Title/Summary/Keyword: Small protein

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Effects of Light on Disassembly of Chloroplast during Senescence of Detached Leaves in Phaseolus vulgaris

  • Dong-Hee Lee;Jun
    • Journal of Environmental Science International
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    • v.1 no.2
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    • pp.69-80
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    • 1992
  • Effects of light on leaf senescence of Phseolus vulgaris were investigated by measuring the disassembly of chlorophyll-protein complexes in detached leaves which had been kept in the dark or under light. The loss of chlorophyll accompanied by degradation of chlorophyll- protein complexes. PSI (photosystem I) complex containing LHCI (light harvesting complex of PSI) apoproteins was rapidly decreased after the early stage of dark-induced senescence. RC(reaction center)-Cores was slightly increased until 4 d and slowly decreased thereafter. As disassembly of LHCII trimer progressed after the late stage of senescence, there was a steady increase in the relative amount of SC(small complex)-2 containing LHCII monomer. On the other hand, white and red light adaptation caused the structural stability of chlorophyll-protein complexes during dark-induced senescence. Particularly, red light was more effective in the retardation of LHCII breakdown than white light, whereas white light was slightly effect in protecting the disassembly of PSI complex compared to red light. These results suggest, therefore, that light may be a regulatory factor for stability of chlorophyll-protein complexes in the senescent leaves.

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Computer Model for Fibrinogen Adsorption on Polyurethane Surface

  • Kim, Jong-Won;Shin, In-Sun;Ryu, Gyu-Ha;Lee, Kyu-Back;Han, Dong-Keun;Kim, Young-Ha;Min, Byoung-Goo
    • Journal of Biomedical Engineering Research
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    • v.15 no.1
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    • pp.51-56
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    • 1994
  • Protein adsorption on the polyurethane surface was modelled by a modified random sequential adsorption(RSA) process. In this model, polyurethane surface was modelled as a mixed domain of hydrophobic and hydrophilic parts which was implemented by a 2 dimensional $150{\times}150$ lattice in the computer. Protein adsorption was simulated using a small box which represents a particle of the protein, and polyurethane lattice by considering their hydrophobic interaction. In order to validate the model, we perfonned fibrinogen adsorption on polyurethane surface. Isotherms of the adsorbed protein were calculated and compared to the experimental data. The protein adsorption on the polyurethane surface could be well described using this computer model.

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Substrate Specificity of Protein Kinase UL97, an antiviral target, on Mutant Peptide Substrates Derived from a Peptide, KESYSVYVYKV (KESYSVYVYKV로부터 변형된 펩타이드 기질을 이용한 항바이러스제의 타깃이 되는 UL97 단백질 인산화 효소의 기질 특이성)

  • Baek, Moon-Chang
    • YAKHAK HOEJI
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    • v.52 no.6
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    • pp.466-470
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    • 2008
  • Human cytomegalovirus expresses an unusual protein kinase UL97, a member of ${H_V}{U_L}$ family of protein kinase. UL97 can phosphorylate nucleoside analogs such as ganciclovir as well as protein/peptide. It has previously been reported that UL97 is able to phosphorylate a KESYSVYVYKV peptide and that P+5 position (K) is important. We examined the extent of contribution of other positions (P-4 through P+6) of the peptide to be substrate of UL97 using alanine substituted peptides (Ala scanning) and deleted peptides. The result suggested that the E (P-2) is negative effect and P+5 (K) is still important. The peptide YSVYVYK is the shortest substrate enough to show high activity, which could be a starting point to develop peptidomimetic drug. This study would give important information to deeply understand the substrate specificity of UL97 and develop an antiviral drug using the small peptide identified here.

Clinical Significance of Increased Ki-67 Protein Expression in Non-small Cell Lung Cancers (비소세포폐암 환자에시 Ki-67 단백질 발현증가의 임상적 의의)

  • Lee Gun;Lim Chang-Young;Kim Kwang-Il;Lee Hyeon-Jae
    • Journal of Chest Surgery
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    • v.39 no.5 s.262
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    • pp.376-381
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    • 2006
  • Background: The Ki-67 protein is a biomarker associated with cell proliferation and a valuable negative prognostic factor in non-small cell lung cancer. We investigated the Ki-67 protein expression in resected non-small cell lung cancer to evaluate the impact on clinicopathological characteristics and postoperative prognosis. Material and Method: Using monoclonal antibody Ki-67, we immunohistochemically examined 38 surgically resected non-small ceil lung cancers to determine Ki-67 Labeling Index (LI). We analysed the differences of clinicopathological characteristics and postoperative recurrence and survival between High Ki-67 Group $(LI{\ge}20%)$ and Low Ki-67 Group (LI<20%). Result: The Ki-67 LIs were heterogenous and a mean values was $20.0{\pm}20.05%$. There were no significant differences in age, sex, smoking, TNM stage, and vascular invasion between High Ki-67 Group and Low Ki-67 Group. A High Ki-67 Group was significantly associated with squamous cell type, poor differentiation, and lymphatic invasion $(p{\le}0.05)$. High Ki-67 Group showed a trend of lower survival (median 47.2 vs. 90.5 months, p=0.312) and lower disease-free survival (median 18.2 vs. 72.3 months, p=0.327) than Low Ki-67 Group. Conclusion: These results indicate that increased Ki-67 protein expression may be a negative prognostic factor and showed a trend of shortened survival and disease-free survival. To evaluate the pivotal role of Ki-67 protein expression, a long-term follow-up and further study are required.

An OTHBVS Cell Line Expresses the Human HBV Middle S Protein

  • Park, Sung-Gyoo;Guhung Jung
    • Journal of Microbiology
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    • v.37 no.2
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    • pp.86-89
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    • 1999
  • An OTHBVS cell line from HepG2 was established. This cell line stably expresses the human hepatitis B virus (HBV) middle S protein that includes the preS2 region which is important for HBV particle entry into the hepatocyte. To establish this cell line, the middle S open reading frame (ORF), with a promoter located in the 5' region and enhancer located in the 3' region, was cloned downstream from the metallothionine (MT) promoter of the OT1529 vector. In this vector, expression of the middle S protein was constructed to be regulated by its own promoter and enhancer. Expression of the large S protein which contains the preS1 region in addition to the middle S protein was designed to be regulated by the MT promoter. When extracts of OTHBVS cells were examined with an S protein detection kit (RPHA, Korea Green Cross Co.), an S protein was detected. Total mRNA of OTHBVS cell examined by northern blot analysis with an S ORF probe revealed small/middle S transcripts (2.1 kb). When the MT promoter was induced by Zn, large S transcripts (2.4 kb) were detected. The GP36 and GP33 middle S proteins were presumably detected, but large S proteins were not detected by immunostain analysis using anti-preS2 antibody.

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TNF-${\alpha}$ Up-regulated the Expression of HuR, a Prognostic Marker for Ovarian Cancer and Hu Syndrome, in BJAB Cells

  • Lee, Kyung-Yeol
    • IMMUNE NETWORK
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    • v.4 no.3
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    • pp.184-189
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    • 2004
  • Background: Hu syndrome, a neurological disorder, is characterized by the remote effect of small cell lung cancer on the neural degeneration. The suspicious effectors for this disease are anti-Hu autoantibodies or Hu-related CD8+ T lymphocytes. Interestingly, the same effectors have been suggested to act against tumor growth and this phenomenon may represent natural tumor immunity. For these diagnostic and therapeutic reasons, the demand for antibodies against Hu protein is rapidly growing. Methods: Polyclonal and monoclonal antibodies were generated using recombinant HuR protein. Western blot analyses were performed to check the specificity of generated antibodies using various recombinant proteins and cell lysates. Extracellular stimuli for HuR expression had been searched and HuR-associated proteins were isolated from polysome lysates and then separated in a 2-dimensional gel. Results: Polyclonal and monoclonal antibodies against HuR protein were generated and these antibodies showed HuR specificity. Antibodies were also useful to detect and immunoprecipitate endogenous HuR protein in Jurkat and BJAB. This report also revealed that TNF-${\alpha}$ treatment in BJAB up-regulated HuR expression. Lastly, protein profile in HuR-associated mRNAprotein complexes was mapped by 2-dimensional gel electrophoresis. Conclusion: This study reported that new antibodies against HuR protein were successfully generated. Currently, project to develop a diagnostic kit is in process. Also, this report showed that TNF-${\alpha}$ up-regulated HuR expression in BJAB and protein profile associated with HuR protein was mapped.

Effects of Protein and Iron Concentrations on Iron Solubility in Black Tea Infusion (단백질 함량 및 철분 농도의 변화에 따라 홍차 추출물이 철분의 용해도에 미치는 영향)

  • 김희선
    • Journal of Nutrition and Health
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    • v.29 no.8
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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.

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Rheological Properties of Jeung-pyun Prepared with SPI(Soybean Protein Isolates) (분리 대두 단백질 첨가에 의한 증편의 이화학적 특성)

  • Hong, Geum-Ju;Kim, Myung-Hee;Kim, Kang-Sung
    • Journal of the East Asian Society of Dietary Life
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    • v.18 no.1
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    • pp.1-8
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    • 2008
  • In this study the rheological properties of Jeung-pyun prepared with soybean protein isolate (SPI) were investigated. SPI Jeung-pyun samples were manufactured with 3% whole protein, 7S protein, or 11S protein (w/w). In terms of moisture content the Jeung-pyun samples prepared with soybean flour had greater moisture contents than the control group. With the addition of SPI water binding capacity solubility and swelling power increased. Dough pH decreased during the fermentation, but increased after steaming and the SPI Jeung-pyun samples presented higher pH levels han the control group. Foaming ability was significantly strong in the 7S, 11S and whole protein groups. The surface structures of the 7S, 11S and whole protein Jeung-pyun samples displayed small uniform pores when examined by SEM. Overall, the results suggest that SPI can contribute to quality improvements in Jeung-pyun through effects on dough fermentation.

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Changes in Photosynthetic Rate and Protein Content in the Leaf during the Senescence of Tobacco Plant (Nicotiana tabacum L) (담배의 노화과정 중 광합성 및 단백질 함량의 변화)

  • Lee, Sang-Gak;Shim, Sang-In;Kang, Byeung-Hoa
    • Journal of the Korean Society of Tobacco Science
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    • v.17 no.1
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    • pp.20-26
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    • 1995
  • This study was carried out to obtain the basic data which include the change of the photosynthetic rate and protein content according to growth stage in the process of senescence of tobacco plant The photosynthetic rate was the maximum with 26.31$\mu$mol.CO2/m2.sec and stomatal resistance was the minimum with 0.2552cm/sec at 15th days after leaf emergence. However, after 50 days the photosynthesis was very little occurred. During leaf developments the number of chloroplast was increased and reached at the maximum at 25th days after emergence of leaf, thereafter, it was decreased gradually. The content of protein increased continuously and showed the highest value at 15th days after leaf emergence. The degradation rate of soluble protein was more rapid than that of insoluble protein at early stage of senescence. The range of decrement in the insoluble protein was low at late stage of senescence. The content of Rubisco, the key enzyme of photoamthesis, corresponded to about 50% of soluble protein and reached to the maximum at 150 days after leaf emergence. As the senescence progressed, the content of large subunit(UV) of Rubisco showed a tendency to decrease more rapidly than that of small subunit(SSU). The total amount of amino acids was the highest at 15th days after leaf emergence.

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Short-term protein intake increases fractional synthesis rate of muscle protein in the elderly: meta-analysis

  • Gweon, Hyun-Soo;Sung, Hee-Ja;Lee, Dae-Hee
    • Nutrition Research and Practice
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    • v.4 no.5
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    • pp.375-382
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    • 2010
  • The precise effects of protein intake on fractional synthesis rate (FSR) of muscle protein are still under debate. The sample size of these studies was small and the conclusions in young and elderly subjects were inconsistent. To assess the effect of dietary protein intake on the FSR level, we conducted a meta-analysis of controlled protein intake trials. Random-effects models were used to calculate the weighted mean differences (WMDs). Ten studies were included and effects of short-term protein intake were evaluated. In an overall pooled estimate, protein intake significantly increased the FSR (20 trials, 368 participants; WMD: 0.025%/h; 95%CI: 0.019-0.031; P < 0.0001). Meta-regression analysis suggested that the protein dose was positively related to the effect size (regression coefficient = 0.108%/h; 95%CI: 0.035, 0.182; P = 0.009). A subgroup analysis indicated that protein intake significantly increased FSR when the protein dose was ${\leq}$ 0.80 g/kg BW (16 trials, 308 participants; WMD: 0.027%/h; 95%CI: 0.019-0.031; P < 0.0001), but did not affect FSR when the protein dose was > 0.80 g/kg BW (4 trials, 60 participants; WMD: 0.016%/h; 95%CI: 0.004-0.029; P = 0.98). In conclusion, this study is the first integrated results showing that a short-term protein intake is effective at improving the FSR of muscle protein in the healthy elderly as well as young subjects. This beneficial effect seems to be dose-dependent when the dose levels of protein range from 0.08 to 0.80 g/kg BW.