• Title/Summary/Keyword: protein stabilization

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Stabilization of .betha.-D-galactosidase from heat and chemical inactivation with the extract of panax ginseng C. A. Meyer

  • Kim, Doo-Ha;Hahn, Younghe;Hong, Soon-Keun
    • Archives of Pharmacal Research
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    • v.5 no.2
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    • pp.45-52
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    • 1982
  • Staibilization effect of Panax ginseng C. A. Meyer on .betha.-D-Galactosidase inactivation was proved by kinetic studies of thermal inactivation of the enzyme. The water extract Panax ginseng C. A. Meyer showed stabilization activity at minimal concentration of 10ppm. The methanolic extract was purified to obtain ginseng saponins, and two groups of the ginsenosides, i. e. protopanaxadiol and protopanaxatriol were isolated. They also showed a protective effect against the thermal and chemical inactivation of the enzyme; p-chloromercuribenzoic acid and hydroxylamine known as protein modifier greatly inactivated the enzyme but inactivation was significantly balocked by the ginseng component MG$^{2+}$, known as a cofactor, stabilized the enzyme and the poor stabilization effect by it was potentiated by ginseng components.s.

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Protein Kinase A Increases DNA-Binding Activity of Testis-Brain RNA-Binding Protein

  • Ju, Hyun-Hee;Ghil, Sung-Ho
    • Biomedical Science Letters
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    • v.14 no.2
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    • pp.77-81
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    • 2008
  • Testis brain RNA-binding protein (TB-RBP) is a DNA/RNA binding protein. TB-RBP is mainly expressed in testis and brain and highly conserved protein with several functions, including chromosomal translocations, DNA repair, mitotic cell division, and mRNA transport, stabilization, and storage. In our previous study, we identified TB-RBP as an interacting partner for the catalytic subunit $(C{\alpha})$ of protein kinase A(PKA) and verified their interaction with several biochemical analyses. Here, we confirmed interaction between $C{\alpha}$. and TB-RBP in mammalian cells and determined the effect of $C{\alpha}$. on the function of TB-RBP. The activation of $C{\alpha}$. increased the TB-RBP function as a DNA-binding protein. These results suggest that the function of TB-RBP can be modulated by PKA and provide insights into the diverse role of PKA.

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Cloning and Characterization of Ribosome-associated Membrane Protein 4 (RAMP4) gene in silkworm Bombyx mori

  • Yao Qin;Hu Zhigang;Xu Jiaping;Chen Keping
    • International Journal of Industrial Entomology and Biomaterials
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    • v.10 no.2
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    • pp.125-129
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    • 2005
  • Ribosome-associated membrane protein 4 (RAMP4) is a membrane protein that exposes its N-terminal hydrophilic portion on the cytoplasmic side and spans the membrane close to the C-terminal end. RAMP4 has previously been reported to belong to the set of proteins that remains associated with membrane-bound ribosomes, and controls the glycosylation of major histocompatbility complex class II-associated invariant chain. RAMP4 also may be relative to the stabilization of membrane proteins in response to stress, with other components of translocon, and molecular chaperons in ER. Application of 5'-RACE technique with specially designed primer, we cloned a 715 bp cDNA fragment which contains a 195 bp ORF, termed RAMP4. The deduced protein has 64 amino acid residues and contains a putative transmembrane-spanning domain at the COOH terminus.

Milk Protein-Stabilized Emulsion Delivery System and Its Application to Foods

  • Ha, Ho-Kyung;Lee, Won-Jae
    • Journal of Dairy Science and Biotechnology
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    • v.38 no.4
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    • pp.189-196
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    • 2020
  • Milk proteins, such as casein and whey protein, exhibit significant potential as natural emulsifiers for the preparation and stabilization of emulsion-based delivery systems. This can be attributed to their unique functional properties, such as the amphiphilic nature, GRAS (generally recognized as safe) status, high nutritional value, and viscoelastic film-forming ability around oil droplets. In addition, milk protein has been used as a coating material in emulsion-based delivery systems to protect bioactive compounds during food processing and storage owing to its unique functional properties. These properties include the ability to bind lipophilic bioactive compounds and antioxidant activity. In this review, we present the use of milk proteins as emulsifiers for the formation of emulsions and food applications of milk protein-stabilized emulsion delivery systems.

Effects of Plasma on the Surface of Protein Chip Plates (단백질 칩 기판의 플라즈마 효과)

  • Hyun, J.W.;Kim, N.Y.
    • Journal of the Korean Vacuum Society
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    • v.17 no.6
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    • pp.549-554
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    • 2008
  • Nickel Chloride coated protein chip plates were developed by using a spin coating method after $H_2$ plasma treatment. The adsorption ability of histidine tagged protein was investigated at various times of plasma treatment. The properties of the nickel chloride and protein on the surface of the slides were assayed using particle size analysis and the extent of the protein adsorption was determined by using a bio imaging analyzer system. The results show that the ability of protein adsorption decreased as increasing the time of $H_2$ plasma treatment. The mechanism on the ability of protein adsorption at the plate surface is discussed on results and discussions. The results also suggest that the surface stabilization of protein chip plates treated by plasma technology may be applicable in biosensor markets.

GIGANTEA Regulates the Timing Stabilization of CONSTANS by Altering the Interaction between FKF1 and ZEITLUPE

  • Hwang, Dae Yeon;Park, Sangkyu;Lee, Sungbeom;Lee, Seung Sik;Imaizumi, Takato;Song, Young Hun
    • Molecules and Cells
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    • v.42 no.10
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    • pp.693-701
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    • 2019
  • Plants monitor changes in day length to coordinate their flowering time with appropriate seasons. In Arabidopsis, the diel and seasonal regulation of CONSTANS (CO) protein stability is crucial for the induction of FLOWERING LOCUS T (FT) gene in long days. FLAVIN-BINDING, KELCH REPEAT, F-BOX 1 (FKF1) and ZEITLUPE (ZTL) proteins control the shape of CO expression profile antagonistically, although regulation mechanisms remain unknown. In this study, we show that GIGANTEA (GI) protein modulates the stability and nuclear function of FKF1, which is closely related to the stabilization of CO in the afternoon of long days. The abundance of FKF1 protein is decreased by the gi mutation, but increased by GI overexpression throughout the day. Unlike the previous report, the translocation of FKF1 to the nucleus was not prevented by ZTL overexpression. In addition, the FKF1-ZTL complex formation is higher in the nucleus than in the cytosol. GI interacts with ZTL in the nucleus, implicating the attenuation of ZTL activity by the GI binding and, in turn, the sequestration of FKF1 from ZTL in the nucleus. We also found that the CO-ZTL complex presents in the nucleus, and CO protein abundance is largely reduced in the afternoon by ZTL overexpression, indicating that ZTL promotes CO degradation by capturing FKF1 in the nucleus under these conditions. Collectively, our findings suggest that GI plays a pivotal role in CO stability for the precise control of flowering by coordinating balanced functional properties of FKF1 and ZTL.

Protective Effect of Biological Osmolytes against Heat- and Chaotropic Agent-Induced Denaturation of Bacillus licheniformis γ-Glutamyl Transpeptidase

  • Lo, Huei-Fen;Chi, Meng-Chun;Lin, Min-Guan;Lan, Yuan-Gin;Wang, Tzu-Fan;Lin, Long-Liu
    • Journal of Microbiology and Biotechnology
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    • v.28 no.9
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    • pp.1457-1466
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    • 2018
  • In the present study, the stabilizing effect of four different biological osmolytes on Bacillus licheniformis ${\gamma}$-glutamyl transpeptidase (BlGGT) was investigated. BlGGT appeared to be stable under temperatures below $40^{\circ}C$, but the enzyme retained less than 10% of its activity at $60^{\circ}C$. The tested osmolytes exhibited different degrees of effectiveness against temperature inactivation of BlGGT, and sucrose was found to be the most effective among these. The use of circular dichroism spectroscopy for studying the secondary structure of BlGGT revealed that the temperature-induced conformational change of the protein molecule could be prevented by the osmolytes. Consistently, the molecular structure of the enzyme was essentially conserved by the osmolytes at elevated temperatures as monitored by fluorescence spectroscopy. Sucrose was further observed to counteract guanidine hydrochloride (GdnHCl)-and urea-induced denaturation of BlGGT. Taken together, we observed evidently that some well-known biological osmolytes, especially sucrose, make a dominant contribution to the structural stabilization of BlGTT.

Effect of Various Carbon Sources on the Production and Stabilization of hGM-CSF in Transgenic Plant Suspension Culture (형질전환된 식물세포에서 hGM-CSF 생산과 안정성에 대한 다양한 탄소원의 효과)

  • Lee Jae-Hwa
    • Journal of Plant Biotechnology
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    • v.32 no.4
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    • pp.313-319
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    • 2005
  • The effects of various carbon sources on the secretion of hGM-CSF, total protein and protease into the medium were investigated in transgenic tobacco cells. The dry cell weight (11.2 g/L) and wet cell weight (310.8 g/L) were highest at 30 g/L glucose after 5-day culture but, the dry cell weight (13.4 g/L) and wet cell weight (480 g/L) were highest at 30 g/L sucrose after 10-day culture. The total protein (110.3 mg/L), protease activity (3950 U/L) and total secreted hGM-CSF (56 mg/L) were highest at 30 g/L sucrose after 10-day culture. Stabilization of the total secreted protein and hGM-CSF in various carbon source concentrations was determined. Total secreted protein was most stabilized in the medium containing sucrose. However, the loss of the total protein was increased with the concentrations of high level in medium containing sorbitol, mannitol, fructose, and glucose. hGM-CSF was more stabilized in the medium containing sucrose than in the medium containing sorbitol, mannitol, fructose, glucose.

Cryoprotectant Effects of Fructo-, Isomalto-, and Galacto-Oligosaccharides on Beef Protein (프락토, 이소말토 및 갈락토 올리고당들의 쇠고기단백질 냉동변성방지효과 연구)

  • 이경숙;이현규;양차범;박관화
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.30 no.3
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    • pp.565-568
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    • 2001
  • A study was conducted to investigate cryoprotectant effect of commercially produced oligosaccharides (IMO: isomalto-oligosaccharides, FO: fructo-oligosaccharides and GO: galacto-oligosaccharides) on beef protein and to compare their effectiveness to sucrose or a mixture of sucrose and sorbitol on freezing. The optimal addition level of cryoprotectants was determined by measuring $Ca^{2+}$-ATPase activity of sample treated with different concentration (0 to 12%) after freeze-thaw cycle. Since the stabilization effect was not dramatically increased above 8% sugar concentrations, the 8% was determined as an usage level. During frozen storage (at -18$^{\circ}C$ for 12 week), commercially produced oligosaccharides showed lower cryoprotection ability than sucrose but higher than sucrose+sorbitol as measured by protein solubilities and $Ca^{2+}$-ATPase activities.

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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.