• Title/Summary/Keyword: Protein engineering

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Biological Activity of Recombinant Human Erythropoietin (EPO) In Vivo and In Vitro

  • Park Jong-Ju;Lee Hyen-Gi;Nam In-Suk;Park Hee-Ja;Kim Min-Su;Chung Yun-Hi;Naidansuren Purevjargal;Kang Hye-Young;Lee Poong-Yun;Park Jin-Gi;Seong Hwan-Hoo;Chang Won-Kyong;Kang Myung-Hwa
    • Reproductive and Developmental Biology
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    • v.29 no.2
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    • pp.69-73
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    • 2005
  • The hematopoietic growth factor erythropoietin (EPO) is required for the maintenance, proliferation, and differentiation of the stem cells that produce erythrocytes. To analyse the biological activity of the recombinant human EPO (rec-hEPO), we have cloned the EPO cDNA and genomic DNA and produced rec-hEPO in the CHO cell lines. The growth and differentiation of EPO-dependent human leukemic cell line (F36E) were used to measure cytokine dependency and in vitro bioactivity of rec-hEPO. MIT assay values were increased by survival of F36E cells at 24h or 72h. The hematocrit and RBC values were increased by subcutaneous injection of 20 IU (in mice) and 100IU(in rats) rec-hEPO. Hematocrit values remarkably increased at $13.2\%$ (in mice) and $12.2\%$ (in rats). The pharmacokinetic behavior with injection of 6 IU of rec-hEPO remained detectable after 24 h in all mice tested. The highest peat appeared at 2h after injection. The long half-life of rec-hEPO is likely to confer clinical advantages by allowing less frequent dosing in patients treated for anemia. These data demonstratethat ree-hEPO produced in this study has a potent activity in vivo and in vitro. The results also suggest that biological activity of ree-hEPO could be remarkably enhanced by genetic engineering that affects the potential activity, including mutants with added oligosaccharide chain and designed to produce EPO-EPO fusion protein.

FNC, a Novel Nucleoside Analogue, Blocks Invasion of Aggressive Non-Hodgkin Lymphoma Cell Lines Via Inhibition of the Wnt/β-Catenin Signaling Pathway

  • Zhang, Yan;Wang, Chen-Ping;Ding, Xi-Xi;Wang, Ning;Ma, Fang;Jiang, Jin-Hua;Wang, Qing-Duan;Chang, Jun-Biao
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.16
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    • pp.6829-6835
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    • 2014
  • Chemotherapy is the primary therapy for malignant lymphoma (ML). However, the clinical outcome is still far from satisfactory. Consequently, an understanding of the mechanism of modulating cancer cell invasion, migration and metastasis is important for the development of more effective chemotherapeutic agents. FNC, 2'-deoxy-2'-${\beta}$-fluoro-4'-azidocytidine, a novel cytidine analogue, has demonstrated significantly inhibitory effects on proliferation of several non-Hodgkin lymphoma (NHL) cell lines. A previous study indicated that FNC effectively inhibited the growth of Raji and JeKo-1 cells in dose-time dependent effects with $IC_{50}$ values of $0.2{\mu}M$ and $0.097{\mu}M$, respectively. This study was focused on investigating the anti-invasive properties of FNC on NHL cells and its potential mechanisms of action. Cell adhesion and transwell chamber assays were utilized to investigate the anti-invasive effects of FNC on Raji and JeKo-1 cells. Real-time PCR and Western blotting were employed to qualify the expression of ${\beta}$-catenin, the glycogen synthase kinase-3 beta (GSK-$3{\beta}$), E-cadherin vascular endothelial growth factor (VEGF), matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9). The results revealed that FNC remarkably inhibited the adhesion, migration and invasion of two human aggressive non-Hodgkin lymphoma cell lines in a dose dependent manner. Furthermore, ${\beta}$-catenin, MMP-2, MMP-9, VEGF mRNA and protein levels were decreased after FNC treatment, while GSK-$3{\beta}$ and E-cadherin increased. Our studies thus provide evidence and a rationale that FNC may offer an effective chemotherapeutic agent by regulating the invasion and metastasis of aggressive non-Hodgkin lymphoma via inhibition of the Wnt/${\beta}$-catenin signaling pathway.

Cloning, Expression, and Characterization of a New Xylanase from Alkalophilic Paenibacillus sp. 12-11

  • Zhao, Yanyu;Meng, Kun;Luo, Huiying;Yang, Peilong;Shi, Pengjun;Huang, Huoqing;Bai, Yingguo;Yao, Bin
    • Journal of Microbiology and Biotechnology
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    • v.21 no.8
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    • pp.861-868
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    • 2011
  • A xylanase gene, xyn7c, was cloned from Paenibacillus sp. 12-11, an alkalophilic strain isolated from the alkaline wastewater sludge of a paper mill, and expressed in Escherichia coli. The full-length gene consists of 1,296 bp and encodes a mature protein of 400 residues (excluding the putative signal peptide) that belongs to the glycoside hydrolase family 10. The optimal pH of the purified recombinant XYN7C was found to be 8.0, and the enzyme had good pH adaptability at 6.5-8.5 and stability over a broad pH range of 5.0-11.0. XYN7C exhibited maximum activity at $55^{\circ}C$ and was thermostable at $50^{\circ}C$ and below. Using wheat arabinoxylan as the substrate, XYN7C had a high specific activity of 1,886 U/mg, and the apparent $K_m$ and $V_{max}$ values were 1.18 mg/ml and 1,961 ${\mu}mol$/mg/min, respectively. XYN7C also had substrate specificity towards various xylans, and was highly resistant to neutral proteases. The main hydrolysis products of xylans were xylose and xylobiose. These properties make XYN7C a promising candidate to be used in biobleaching, baking, and cotton scouring processes.

A Novel Tannase from the Xerophilic Fungus Aspergillus niger GH1

  • Marco, Mata-Gomez;Rodriguez, Luis V.;Ramos, Erika L.;Renovato, Jacqueline;Cruz-Hernandez, Mario A.;Rodriguez, Raul;Contreras, Juan;Aguilar, Cristobal N.
    • Journal of Microbiology and Biotechnology
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    • v.19 no.9
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    • pp.987-996
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    • 2009
  • Aspergillus niger GH1 previously isolated and identified by our group as a wild tannase producer was grown under solid-state (SSC) and submerged culture (SmC) conditions to select the enzyme production system. For tannase purification, extracellular tannase was produced under SSC using polyurethane foam as the inert support. Tannase was purified to apparent homogeneity by ultrafiltration, anion-exchange chromatography, and gel filtration that led to a purified enzyme with a specific activity of 238.14 IU/mg protein with a final yield of 0.3% and a purification fold of 46. Three bands were found on the SDS-PAG with molecular masses of 50, 75, and 100 kDa. PI of 3.5 and 7.1% N-glycosylation were noted. Temperature and pH optima were 600e and 6.0 [methyl 3,4,5-trihydroxybenzoate (MTB) as substrate], respectively. Tannase was found with a $K_M$ value of $0.41{\times}10^{-4}M$ and the value of $V_{max}$ was $11.03{\mu}$moL/min at $60^{\circ}C$ for MTB. Effects of several metal salts, solvents, surfactants, and typical enzyme inhibitors on tannase activity were evaluated to establish the novelty of the enzyme. Finally, the tannase from A. niger GH1 was significantly inhibited by PMSF (phenylmethylsulfonyl fluoride), and therefore, it is possible to consider the presence of a serine or cysteine residue in the catalytic site.

Screening of High-Productivity Cell Lines and Investigation of Their Physiology in Chinese Hamster Ovary (CHO) Cell Cultures for Transforming Growth $Factor-{\beta}1$ Production

  • Chun, Gin-Taek;Lee, Joo-Buom;Nam, Sang-Uk;Lee, Se-Won;Jeong, Yeon-Ho;Choi, Eui-Yul;Kim, Ik-Hwan;Jeong, Yong-Seob;Kim, Pyeong-Hyeun
    • Journal of Microbiology and Biotechnology
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    • v.12 no.1
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    • pp.121-129
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    • 2002
  • Using recombinant Chinese hamster ovary (CHO) cells, strategies for developing high producers for the recombinant human Transforming Growth $Factor-{\beta}1$ ($TGF-{\beta}1$) protein are proposed and their physiological characteristics in cell cultures were investigated. $TGF-{\beta}1$ is a pleiotrophic polypeptide involved in various biological activities, including cell growth, differentiation, and deposition of extracellular matrix proteins. The CHO cells included human $TGF-{\beta}1$ cDNA in conjunction with a dihydrofolate reductase (DHFR) gene, which was cotransfected into the cells to amplify the transfected $TGF-{\beta}1$ cDNA. As a first-round screening of the transfected cells, a relatively high $TGF-{\beta}1$-producing cell line was selected, and then, it acquired a resistance to increasing concentrations of methotrexate (MTX) up to $60{\mu}M$,resulting in a significant improvement in its $TGF-{\beta}1$ biosynthetic ability. After applying a monoclonal selection strategy to the MTX-resistant cells, more productive cells were screened, including the APP-3, App-5, and App-8 cell lines. These high producers were compared with two other cell lines (AP-l cell line without amplification of transfected $TGF-{\beta}1$ cDNA and nontransfectant of $TGF-{\beta}1$ cDNA) in terms of cell growth, $TGF-{\beta}1$ productivity, sugar uptake, and byproduct formation, in the presence or absence of MTX in the culture medium. Consequently, both monoclonal selection as well as an investigation of the physiological characteristics were found to be needed for the efficient screening of higher $TGF-{\beta}1$ producers, even after the transfection and amplification of the transfected gene.

Corticotropin-Releasing Factor Down-Regulates Hair Growth-Related Cytokines in Cultured Human Dermal Papilla Cells (사람 모유두세포에서 코르티코트로핀분비인자에 의한 모발성장관련사이토카인의 발현 조절)

  • Lee, Eun Young;Jeon, Ji Hye;Lee, Min Ho;Lee, Sunghou;Kim, Young Ho;Kang, Sangjin
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.40 no.4
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    • pp.413-421
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    • 2014
  • Corticotropin-releasing factor (CRF) is involved in the stress response and there is increasing evidence that stress influences skin disease such as hair loss. In cultured human hair follicles, CRF inhibits hair shaft elongation, induces premature regression and promotes the apoptosis of hair matrix keratinocytes. We investigated whether CRF influences the dermal papilla cells (DPC) that play pivotal roles in hair growth and cycling. Human DPCs were treated with CRF, adrenocorticotropic hormone (ACTH) and cortisol, key stress hormones along the hypothalamic-pituitary -adrenal (HPA) axis for 1-24 h. Interestingly, CRF modulated the expression of cytokines related to hair growth (KGF, Wnt5a, $TGF{\beta}-2$, Nexin) and increased cAMP production in cultured DPCs. CRF receptors were down-regulated by negative feedback systems. Pretreatment of CRF receptor antagonists or protein kinase A (PKA) inhibitor prevented the CRF-induced modulation. Since the CRF induces proopiomelanocortin (POMC) expression through the cAMP/PKA pathway, we analyzed POMC mRNA. CRF stimulated POMC expression in cultured human DPCs, yet we were unable to detect ACTH levels by western blot. These results indicate that CRF operates within DPCs through CRF receptors along the classical CRF signaling pathway and CRF receptor antagonists could serve as potential therapeutic and cosmetic agents for stress-induced hair loss.

Prediction of Lung Cancer Based on Serum Biomarkers by Gene Expression Programming Methods

  • Yu, Zhuang;Chen, Xiao-Zheng;Cui, Lian-Hua;Si, Hong-Zong;Lu, Hai-Jiao;Liu, Shi-Hai
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.21
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    • pp.9367-9373
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    • 2014
  • In diagnosis of lung cancer, rapid distinction between small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) tumors is very important. Serum markers, including lactate dehydrogenase (LDH), C-reactive protein (CRP), carcino-embryonic antigen (CEA), neurone specific enolase (NSE) and Cyfra21-1, are reported to reflect lung cancer characteristics. In this study classification of lung tumors was made based on biomarkers (measured in 120 NSCLC and 60 SCLC patients) by setting up optimal biomarker joint models with a powerful computerized tool - gene expression programming (GEP). GEP is a learning algorithm that combines the advantages of genetic programming (GP) and genetic algorithms (GA). It specifically focuses on relationships between variables in sets of data and then builds models to explain these relationships, and has been successfully used in formula finding and function mining. As a basis for defining a GEP environment for SCLC and NSCLC prediction, three explicit predictive models were constructed. CEA and NSE are requentlyused lung cancer markers in clinical trials, CRP, LDH and Cyfra21-1 have significant meaning in lung cancer, basis on CEA and NSE we set up three GEP models-GEP 1(CEA, NSE, Cyfra21-1), GEP2 (CEA, NSE, LDH), GEP3 (CEA, NSE, CRP). The best classification result of GEP gained when CEA, NSE and Cyfra21-1 were combined: 128 of 135 subjects in the training set and 40 of 45 subjects in the test set were classified correctly, the accuracy rate is 94.8% in training set; on collection of samples for testing, the accuracy rate is 88.9%. With GEP2, the accuracy was significantly decreased by 1.5% and 6.6% in training set and test set, in GEP3 was 0.82% and 4.45% respectively. Serum Cyfra21-1 is a useful and sensitive serum biomarker in discriminating between NSCLC and SCLC. GEP modeling is a promising and excellent tool in diagnosis of lung cancer.

Quality Characteristics of Muffins containing Maesangi Powder Abstract (매생이가루 첨가량에 따른 머핀의 품질특성)

  • Seo, Eun-Ok;Kim, Kwang-Oh;Ko, Seong-Hye;Park, Jin-Hee;Han, Eun-Ju;Cha, Kyung-Ok;Ko, Eun-Hee
    • Journal of the East Asian Society of Dietary Life
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    • v.22 no.3
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    • pp.414-421
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    • 2012
  • Moisture content of muffin tended to increased as increasing mixing rate of maesangi. For crude protein, sample group of 9% replaced by maesangi powder was the highest. For crude fat and crude ash, there was no significant difference among sample groups. The average height of muffin was 4.7 cm, but was no significant difference among sample groups. Volume of muffin has been gradually increased as increasing mixing rate of maesangi powder, but was no significant difference among sample groups. From the SEM (scanning electron microscope) result, thick cell wall and rough blowholes were appeared. L-, a and b-values of muffin was declined as per increase of mixing rate of maesangi powder. Hardness was inclined as per increase of mixing rate of maesangi powder. There were significant differences between sample groups and reference group for adhesiveness, springiness and cohesiveness, but was no significant difference among sample groups. For gumminess, sample group of 9% replaced by maesangi powder was the highest, but there were no significant difference from sample groups of 3% and 6% replaced by maesangi powder. Chewiness was inclined as per increase of mixing rate of maesangi powder, and sample group of 9% replaced by maesangi powder was the highest. From sensory test result, sample group of 9% replaced by maesangi powder was the highest for color, and there were significant differences among sample groups. Sample group of 6% replaced by maesangi powder was the highest for flavor and taste, and there were significant differences among sample groups. Sample groups of 6% and 9% replaced by maesangi powder were the highest for texture. Sample group of 9% replaced by maesangi powder was the highest for overall preference. From all these results, the most suitable one would be the sample group of 9% replaced by maesangi powder.

Taxifolin Inhibited the Nitric Oxide Production and Expression of Pro-inflammatory Cytokine mRNA in Lipopolysaccharide-stimulated RAW264.7 Cells

  • Rhee, Man-Hee;Endale, Mehari;Kamruzzaman, SM;Lee, Whi-Min;Park, Hwa-Jin;Yoo, Myung-Jo;Cho, Jae-Youl
    • Biomedical Science Letters
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    • v.14 no.3
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    • pp.147-155
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    • 2008
  • In previous works, we found that solvent extract of Opuntia humifusa Raf., a member of the lactaceae family, displayed potent anti-oxidative and anti-inflammatory activities. Thus, all solvent fractions, except for the water layer, showed potent scavenging effects. According to activity-guided fractionation, one of active radical scavenging principles in the ethyl acetate fraction was found to be taxifolin. In this study, we investigated whether taxifolin showed anti-oxidative activity. In addition, taxifolin modulated nitric oxide (NO) release and the expression of pro-inflammatory cytokine mRNA such as interleukin-$1{\beta}$ (IL-$1{\beta}$), IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF), and TNF-${\alpha}$. Taxifolin showed potent anti-oxidant activity with the $IC_{50}\;of\;8.5{\pm}1.4\;and\;9.3{\pm}1.0{\mu}M$ using xanthine/xanthine oxidase (XO) assay and 2,2-Diphenyl-lpicrylhydrazyl radical (DPPH) assay, respectively. We next determined the role of taxifolin on the immunomodulating activity using murine macrophage cell line RAW264.7 cells. Taxifolin dose-dependently inhibited NO production in lipopolysaccharide (LPS)-activated RAW264.7. It also significantly blocked the expression of inducible NO synthase (iNOS) mRNA in the LPS-stimulated RAW264.7 cells. In addition, taxifolin potently suppressed the expression of IL-$1{\beta}$, IL-6 and GM-CSF mRNA in LPS-activated RAW264.7 cells, but not that of TNF-${\alpha}$ Moreover, taxifolin significantly inhibited the transcriptional activity of nuclear factor-${\kappa}B$ (NF-${\kappa}B$) and activator protein -1 (AP-1). These results suggest that taxifolin may downregulate inflammatory iNOS, IL-$1{\beta}$, IL-6 and GM-CSF gene expressions through inhibition of NF-K and AP-1 activation in LPS-stimulated RAW264.7 cells.

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Phylogenetic Analysis of Native Vigna sinensis in Korea Using DNA Sequence of Internal Transcribed spacer (ITS) Region (토종 갓끈동부의 ITS1, 5.8S 및 ITS2의 염기서열을 이용한 계통 분석)

  • Seo, Pil-Soo;Lee, Sook-Young;Shin, Yong Kook
    • Journal of Life Science
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    • v.27 no.3
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    • pp.351-354
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    • 2017
  • Cowpea (Vigna unguiculata (L.) Walp.) is recognized as a potential source of protein and other nutrients. The genus Vigna includes 100 wild species of plants. Especially, Vigna unguiculata includes annual cowpeas (ssp. unguiculata) and ten wild perennial subspecies. DNA sequence of internal transcribed spacer (ITS) region was determined for Vigna sinensis, one of native plant, which was found in recent but thought to have gone extinct in Korea. The seeds of Vigna sinensis used in this study were donated from Dong-Young Jo. The DNA sequence of ITS-5.8S-ITS2 for Vigna sinensis obtained from this study was deposited as Vigna sinensis AY195581 on GenBank of NCBI (National Center for Biotechnology Information). We investigated the sequence-based phylogenetic relationships of plants related and clarified its taxonomical position. DNA similarities among subspecies including Vigna unguiculata showed the range 98 to 100% in sequence-based phylogenetic analysis using total 507 base pairs of ITS1, 5.8S and ITS2. Vigna unguiculata and subspecies were grouped independently as one cluster from other Vigna species used in the phylogenetic analysis. In this study, based on the phylogenetic analysis using the ITS1-5.8S-ITS2 sequence of Vigna sinensis, it may be concluded to be classified to one of Vigna unguiculata substrains.