• Title/Summary/Keyword: protein A

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Reconstruction of α-helices in a Protein Molecule (단백질 분자 내 α-헬릭스의 재구성)

  • Kang, Beom Sik;Kim, Ku-Jin;Seo, U Deok
    • KIPS Transactions on Software and Data Engineering
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    • v.3 no.4
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    • pp.163-168
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    • 2014
  • In a protein molecule, ${\alpha}$-helices are important for protein structure, function, and binding to other proteins, so the analysis on the structure of helices has been researched. Since an interaction between two helices is evaluated based on their axes, massive errors in protein structure analysis would be caused if a curved or kinked long ${\alpha}$-helix is considered as a linear one. In this paper, we present an algorithm to reconstruct ${\alpha}$-helices in a protein molecule as a sequence of straight helices under given threshold.

Computational Approaches for Structural and Functional Genomics

  • Brenner, Steven-E.
    • Proceedings of the Korean Society for Bioinformatics Conference
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    • 2000.11a
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    • pp.17-20
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    • 2000
  • Structural genomics aims to provide a good experimental structure or computational model of every tractable protein in a complete genome. Underlying this goal is the immense value of protein structure, especially in permitting recognition of distant evolutionary relationships for proteins whose sequence analysis has failed to find any significant homolog. A considerable fraction of the genes in all sequenced genomes have no known function, and structure determination provides a direct means of revealing homology that may be used to infer their putative molecular function. The solved structures will be similarly useful for elucidating the biochemical or biophysical role of proteins that have been previously ascribed only phenotypic functions. More generally, knowledge of an increasingly complete repertoire of protein structures will aid structure prediction methods, improve understanding of protein structure, and ultimately lend insight into molecular interactions and pathways. We use computational methods to select families whose structures cannot be predicted and which are likely to be amenable to experimental characterization. Methods to be employed included modern sequence analysis and clustering algorithms. A critical component is consultation of the presage database for structural genomics, which records the community's experimental work underway and computational predictions. The protein families are ranked according to several criteria including taxonomic diversity and known functional information. Individual proteins, often homologs from hyperthermophiles, are selected from these families as targets for structure determination. The solved structures are examined for structural similarity to other proteins of known structure. Homologous proteins in sequence databases are computationally modeled, to provide a resource of protein structure models complementing the experimentally solved protein structures.

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Effect of Plant Growth Regulators on Changes of Chlorophyll, Protein and RNA content in Tobaco-leaves Senescence (식물생장조절제(植物生長調節劑)가 엽연초(葉煙草)의 엽록소(葉緣素) 단백질(蛋白質) 및 RNA의 감소(減少)에 미치는 영향(影響))

  • Bae, H.W.
    • Applied Biological Chemistry
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    • v.12
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    • pp.107-114
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    • 1969
  • In order to elucidate the effects displayed by the plant growth regulators on the senecence of tobacco leaves, the author applied gibberellic acid, Kinetin, Indole-acetic acid, uracil, and malefic hydrazide to the excised leaves in concentration of 25mg/l of each regulators. And author obtained the results as following, 1. Parallel to the decreases of chlorophyll, the amounts of protein and RNA were decreased. 2. The supression of decrease of the amounts of RNA and protein was displayed by the plant growth regulators, G.A., I.A.A.. The decrease of them in M.A. treatments was more than in non-treatments. 3. The ratio changes of chlorophyll a/b and the changes of protein and RNA content seemed to be no relations.

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Human Ribosomal Protein L18a Interacts with hnRNP E1

  • Han, Sun-Young;Choi, Mie-Young
    • Animal cells and systems
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    • v.12 no.3
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    • pp.143-148
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    • 2008
  • Heterogeneous nuclear ribonucleoprotein E1(hnRNP E1) is one of the primary pre-mRNA binding proteins in human cells. It consists of 356 amino acid residues and harbors three hnRNP K homology(KH) domains that mediate RNA-binding. The hnRNP E1 protein was shown to play important roles in mRNA stabilization and translational control. In order to enhance our understanding of the cellular functions of hnRNP E1, we searched for interacting proteins through a yeast two-hybrid screening while using HeLa cDNA library as target. One of the cDNA clones was found to be human ribosomal protein L18a cDNA(GenBank accession number BC071920). We demonstrated in this study that human ribosomal protein L18a, a constituent of ribosomal protein large subunit, interacts specifically with hnRNP E1 in the yeast two-hybrid system. Such an interaction was observed for the first time in this study, and was also verified by biochemical assay.

Human selenium binding protein-1 (hSP56) is a negative regulator of HIF-1α and suppresses the malignant characteristics of prostate cancer cells

  • Jeong, Jee-Yeong;Zhou, Jin-Rong;Gao, Chong;Feldman, Laurie;Sytkowski, Arthur J.
    • BMB Reports
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    • v.47 no.7
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    • pp.411-416
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    • 2014
  • In the present study, we demonstrate that ectopic expression of 56-kDa human selenium binding protein-1 (hSP56) in PC-3 cells that do not normally express hSP56 results in a marked inhibition of cell growth in vitro and in vivo. Down-regulation of hSP56 in LNCaP cells that normally express hSP56 results in enhanced anchorage-independent growth. PC-3 cells expressing hSP56 exhibit a significant reduction of hypoxia inducible protein (HIF)-$1{\alpha}$ protein levels under hypoxic conditions without altering HIF-$1{\alpha}$ mRNA (HIF1A) levels. Taken together, our findings strongly suggest that hSP56 plays a critical role in prostate cells by mechanisms including negative regulation of HIF-$1{\alpha}$, thus identifying hSP56 as a candidate anti-oncogene product.

Hypothetical protein predicted to be tumor suppressor: a protein functional analysis

  • Kader, Md. Abdul;Ahammed, Akash;Khan, Md. Sharif;Ashik, Sheikh Abdullah Al;Islam, Md. Shariful;Hossain, Mohammad Uzzal
    • Genomics & Informatics
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    • v.20 no.1
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    • pp.6.1-6.15
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    • 2022
  • Litorilituus sediminis is a Gram-negative, aerobic, novel bacterium under the family of Colwelliaceae, has a stunning hypothetical protein containing domain called von Hippel-Lindau that has significant tumor suppressor activity. Therefore, this study was designed to elucidate the structure and function of the biologically important hypothetical protein EMK97_00595 (QBG34344.1) using several bioinformatics tools. The functional annotation exposed that the hypothetical protein is an extracellular secretory soluble signal peptide and contains the von Hippel-Lindau (VHL; VHL beta) domain that has a significant role in tumor suppression. This domain is conserved throughout evolution, as its homologs are available in various types of the organism like mammals, insects, and nematode. The gene product of VHL has a critical regulatory activity in the ubiquitous oxygen-sensing pathway. This domain has a significant role in inhibiting cell proliferation, angiogenesis progression, kidney cancer, breast cancer, and colon cancer. At last, the current study depicts that the annotated hypothetical protein is linked with tumor suppressor activity which might be of great interest to future research in the higher organism.

Amino Acid Composition and Nutritional Value of Silkworm Larvae Protein (번데기 단백질(蛋白質)의 아미노산조성과 영양가(營養價)에 관한 연구)

  • Park, Jyung Rewng;Lee, Kyung Hee
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.12 no.4
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    • pp.368-373
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    • 1983
  • This study was designed to determine amino acid composition of silkworm larvae protein and to evaluate its nutritional value by rat experiment. Diets were divided into 5 groups; casein ($D_1$), soybean protein ($D_2$), soybean protein+20% silkworm larvae ($D_3$), soybean protein+40% silkworm larvae protein ($D_4$), and silkworm larvae protein ($D_5$). The growth rate, protein efficiency ratio, weight of organs, hematology, and the content of total serum protein and albumin were studied. The amino acid composition of silkworm larvae protein was comparable to the FAO provisional scoring pattern. The protein was especially high in the amount of lysine and methionine indicating that it could be a good supplemental effect for cereals and beans. Growth rate and protein efficiency ratio of silkworm larvae protein were better than soybean protein and these were increased by the addition of silkworm larvae protein. The weight of liver and spleen from silkworm larvae protein group were also higher than soybean protein group and RBC, WBC, Hct and Hb content of 5 groups tested were within the normal ranges. The contents of total serum protein and albumin from soybean protein group were increased by addition of silkworm larvae protein. From the results obtained, it could be stated that the quality of soybean protein might be improved by silkworm larvae protein.

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Selection Attributes and Purchasing Perceptions and Attitudes of Protein Snacks According to Individual Health Lifestyle (개인의 건강 라이프스타일에 따른 단백질 스낵의 선택속성과 구매인식 및 태도)

  • Hwang, Ji Eon;Oh, Ji Eun;Cho, Mi Sook
    • Journal of the Korean Society of Food Culture
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    • v.33 no.4
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    • pp.394-401
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    • 2018
  • This study was conducted to investigate the effects of health lifestyle on high protein snack selection attributes and purchase behaviors among individuals aged 20-30 with high protein snack intake. In addition, the relationship between perception, attitude, satisfaction and recommendation of high protein snacks was invested. Finally, this study aims to provide basic information for marketing high-protein snacks and customized high protein snacks. Analysis of the selection attributes most important for healthy lifestyle, revealed significant differences among all groups excluding the external seeking group (p<0.001). The free living group regarded trust as one of the most important attributes of high protein snack selection, and both the tempered control group and the low-interest group found sensation and price factor to be important. Therefore, when developing high-protein snacks, it is important to determine which attributes of the snack will be highlighted by segmenting the consumer into health lifestyles. Focusing on what ingredients are used to develop high-protein snacks and nutritional ingredients is also important when targeting a free lifestyle group as the main customer. In addition, developing snacks that do not offer depending on the protein content is important when targeting a temperate management group or a low-interest group.

Effect of N-3 Fatty Acids and Dietary Protein Levels on Renal Function in Rats of Different Ages (N-3계 지방산과 단백질 수준이 나이가 다른 흰쥐에서 신장 기능에 미치는 영향)

  • 김화영;정명지;정현주
    • Journal of Nutrition and Health
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    • v.34 no.8
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    • pp.843-849
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    • 2001
  • This study was performed to investigate the effect of n-3 fatty acids and dietary protein levels on renal function. Fifteen-month old male Sprague-Dawley rats were divided into 4 diet groups. Two-month old rats were used as a control group. The experimental diets contained either a% or 25% casein and lipid levels of the diets were 20% by weight. For the control group, the lipid was composed of beef tallow and corn oil on a 1:1 basis, and fish oil was comprised 75% of the fat mixture for the fish oil group. Rats were fed the diets ad libitum for 8 weeks. GFR and urinary protein excretion were higher in high protein groups, while fish oil exhibited no effects. Renal medulla TXB$_2$and PGE$_2$ concentrations tended to be higher in high protein groups and lower in fish oil groups. Light microscopic examinations showed that glomerulosclerosis, tubular atrophy, tubular cast, interstitial inflammation and interstitial fibrosis fended to be higher in aged rats and in high protein groups and lower in fish oil groups. Serum levels of total lipid, triglyceride and total cholesterol were higher in aged rats and lower in fish oil groups while serum HDL-cholesterol level was higher in young rats and in fish oil groups. However, dietary protein level had no effect on serum lipid levels. Serum TBARS concentration was higher in aged rats and in fish oil groups. In conclusion, fish oil caused changes in serum lipid concentrations and eicosanoids metabolism. The effect of fish oil on renal function was less obvious than dietary protein. However, fish oil seemed to be effective in lessening deterioration of renal function due to aging and/or high protein diets through changes in lipid and eicosanoids metabolism.

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Expression and Characterization of Helicobacter pylori Adhesin Protein Linked to Cholera Toxin A2/B Subunits in Escherichia coli

  • Kim, Byung-Oh;Shin, Sung-Seup;Yoo, Young-Hyo;Pyo, Shuk-Neung
    • Journal of Microbiology and Biotechnology
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    • v.10 no.1
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    • pp.56-62
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    • 2000
  • The hpa gene genetically linked to the ctxa2b gene was cloned into the pTED expression vector, and the constructed pTEDhpa/ctxa2b was transformed into Excherichia coli. The fusion protein, the adhesin fused to the cholera toxin subunit A2B (CTXA2B) subunit, was expressed to high levels as inclusion bodies in E. coli. The expressed protein was partially purified by washing the inclusion bodies with working solution containing 8M Urea and 0.1M DTT. Refolding of denatured fusion protein was carried out in the presence of glutathione redox buffer. The refolded fusion protein was purified by size exclusion chromatography. The expressed fusion protein was verified by SDS-PAGE, western blotting with antibodies to both antigenic components of adhesin and cholera toxin subunit B (CTXB), and its N-terminal amino acid sequence was analyzed. The orderly assembled fusion protein was confirmed by modified Gm1-ganglioside ELISA with Abs to adhesin. The results indicate that the purified fusion protein is an Adhesin/CTXA2B protein containing the H. pylori adhesin and $G_{m1}4-ganglioside binding activity of CTXB and the expressed fusion protein in E. coli could be easily purified by the refolding process, Its molecular weight was 168kDa as estimated by size exclusion chromatography. The Adhesin/CTXA2B protein may be used as a candidate antigen for oral immunization against H. pylori.

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