• Preventive Nutrition and Food Science
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• 제19권4호
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• pp.327-332
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• 2014

The purpose of the current study was to determine the effects of the introduction of polysaccharide chains onto the molecular surface of buckwheat proteins on buckwheat protein surface functionality. The whole buckwheat protein fraction (WBP) was prepared using 50 mM phosphate buffer (pH 7.5) containing 0.5 M NaCl and covalently linked with 6 kDa, 17.5 kDa, 40 kDa, 70 kDa, or 200 kDa dextran by Maillard-type glycation through controlled dry-heating at $60^{\circ}C$ and 79% relative humidity for two weeks. Conjugation with 40 kDa dextran improved the water solubility and emulsifying properties of WBP without causing a serious loss of available lysine; 84.9% of the free amino groups were conserved. In addition, we found that the introduction of dextran chains onto the molecular surfaces of WBP attenuated the antigenicity of WBP.

• BMB Reports
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• 제29권2호
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• pp.180-182
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• 1996

One of the essential functions of virus surface proteins is the recognition of specific receptors on target cell membranes, and cellular receptors play an important role in viral pathogenesis. But the earliest steps of hepatitis B virus (HBV) infection, such as hepatocyte receptor interaction with the virus, are poorly understood. Previous work has suggested an important role of the preS1 region of HBV envelope protein in mediating viral binding to hepatocytes. Although hepatitis B virus (HBV) infection appears to be initiated by specific binding of virions to cell membrane structures via one or potentially several viral surface proteins, data showing the identification or isolation of the HBV receptor (s) are not yet available. The receptor-like proteins on the plasma membrane surface of HepG2 cells that bind to PreS1 were separated and identified using affinity chromatography, and the amino-terminal amino acid sequences of the receptor-like proteins were determined.

• Journal of Microbiology and Biotechnology
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• 제27권1호
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• pp.36-42
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• 2017

In this work, we isolated a surface layer protein (SLP) from a Bacillus thuringiensis (Bt) strain to evaluate it cytotoxic effects against MDA-MB-231 human breast cancer cells. AP11 was selected from a g roup of Bt strains using SLP olig onucleotides developed from Bacillus conserved regions. The AP11 strain was grown in Luria Bertani medium until the late exponential phase; an 86 kDa protein was extracted using 5 M LiCl and identified by liquid chromatography-tandem mass spectrometry. It corresponded to a multispecies SLP highly similar to previously described SLPs in Bt. The MDA-MB-231 breast cancer cells $LC_{50}$ was obtained using $0.25{\mu}g/ml$ of the isolated SLP. HaCat non-cancerous cells presented 90% survival using the same protein concentration. Our data suggest that SLP cytotoxicity against MDA-MB-231 could be induced by an interaction with the CDH11 cell membrane receptor.

• Archives of Pharmacal Research
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• 제21권5호
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• pp.521-526
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• 1998

The physicochmical properties of recombinant hepatitis B surface antigen (r-HBsAg), which was expressed in C127 mammalian cell were studied. Using roller bottle culture in DMEM supplemented with fetal bovine serum, 10-15 mg/L of r-HBsAg was produced with about 31% of purification yield. The purity of r-HBsAg by HPLC was 99.8% and electron microscopic examination showed homogeneous spherical particle with 22 nm in diameter, a morphological characteristic of HBsAg. The density of r-HBsAg by CsCI density gradient method was 1.19g/ml and the isoelectric point by Mono $P^{TM}$ HR 5/20 column was 4.6. The analysis of subunit protein pattern using SDS-PAGE followed by scanning densitometry gave 81.3% of S protein and 18.7% of pre-S protein. fluorophore-assisted-carbohydrate-electrophoresis analysis showed the relative amount of carbohydrate to protein was 1.7% and it smajr component was N-acetyl glucosamine, which was about 39% of total carbohydrate. The relative amount of lipid to protein determined by vanillin phosphoric acid method was 32.5% and its major component was phospholipid, which was about 70% of total lipid. The physicochemical properties of C127 mammalian cell-derved r-HBsAg are similar to those of p-HBsAg, suggesting that the r-HBsAg can be used in developing a new preventive vaccine against hepatitis B.

• Biomaterials and Biomechanics in Bioengineering
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• 제3권1호
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• pp.59-69
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• 2016

A surface resisting protein adsorption and cell adhesion is highly desirable for many biomedical applications such as diagnostic devices, biosensors and blood-contacting devices. In this study, a surface conjugated with sulfobetaine molecules was fabricated via the click reaction for the anti-fouling purpose. An alkyne-containing substrate (Alkyne-PPX) was generated by chemical vapor deposition of 4-ethynyl-[2,2]paracyclophane. Azide-ended mono-sulfobetaine molecules were synthesized and then conjugated on Alkyne-PPX via the click reaction. The protein adsorption from 10% serum was reduced by 57%, while the attachment of L929 cells was reduced by 83% onto the sulfobetaine-PPX surface compared to the protein adsorption and cell adhesion on Alkyne-PPX. In conclusion, we demonstrate that conjugation of mono-sulfobetaine molecules via the click chemistry is an effective way for reduction of non-specific protein adsorption and cell attachment.

• Journal of Microbiology and Biotechnology
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• 제22권2호
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• pp.234-238
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• 2012

Recombinant Escherichia coli displaying organophosphorus hydrolase (OPH) was used to overcome the diffusion barrier limitation of organophosphorus pesticides. A new anchor system derived from the N-terminal domain of ice-nucleation protein from Pseudomonas syringae InaV (InaV-N) was used to display OPH onto the surface. The designed sequence was cloned in the vector pET-28a(+) and then was expressed in E. coli. Tracing of the expression location of the recombinant protein using SDS-PAGE showed the presentation of OPH by InaV-N on the outer membrane, and the ability of recombinant E. coli to utilize diazinon as the sole source of energy, without growth inhibition, indicated its significant activity. The location of OPH was detected by comparing the activity of the outer membrane fraction with the inner membrane and cytoplasm fractions. Studies revealed that recombinant E. coli can degrade 50% of 2 mM chlorpyrifos in 2 min. It can be concluded that InaV-N can be used efficiently to display foreign functional protein, and these results highlight the high potential of an engineered bacterium to be used in bioremediation of pesticide-contaminated sources in the environment.

• 폴리머
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• 제28권6호
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• pp.502-508
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• 2004

암을 치료하기 위한 양이온성 리포솜은 화학치료요법의 분야에서 발전되어 왔다. 양이온성 리포솜은 음이온성의 세포 표면에 정전기적 상호작용에 의해 결합이 된다. 본 연구의 목적은 음이온성 세포와 이온결합을 할 수 있는 양이온성 리포솜을 제조하는 것이다. 양이온성 리포솜은 지질인 1,2-디스테로일-sn-글리콜-3-포스포에탄올아민 (DSPE)과 양이온성 고분자인 폴리에틸렌이민 (PEI)을 그라프트 중합으로 합성된 물질로부터 제조하였다. 리포솜 표면의 이온 특성은 제타 포텐셜을 측정하여 확인하였다. 소 혈청 수용액에서 리포솜의 혈장 단백질 흡착 특성은 입자 크기와 탁도 변화를 측정하여 확인하였다. 완충 용액 속에서 리포솜 안정성을 예측하기 위하여 입자 크기를 7일 동안 상온에서 측정하였다. 양이온성 리포솜은 소 혈청 수용액에서 많은 양의 혈장 단백질이 흡착되었다. 이는 혈장 단백은 음전하를 가지고 있어서 양이온성 리포솜의 표면과 잘 붙기 때문이다. 양이온성 폴리에틸렌이민을 이용한 리포솜의 표면 변형은 소 혈청 수용액 내에서 단백질 흡착을 강화시킨다는 것을 예상하게 한다. 또한, 제조된 리포솜의 완충 용액 내에서 7일 동안 안정한 상태임을 관찰하였다.

• Parasites, Hosts and Diseases
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• 제54권4호
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• pp.385-391
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• 2016

The discovery and understanding of antigenic proteins are essential for development of a vaccine against malaria. In Plasmodium falciparum, Pf92 have been characterized as a merozoite surface protein, and this protein is expressed at the late schizont stage, but no study of Pv92, the orthologue of Pf92 in P. vivax, has been reported. Thus, the protein structure of Pv92 was analyzed, and the gene sequence was aligned with that of other Plasmodium spp. using bioinformatics tools. The recombinant Pv92 protein was expressed and purified using bacterial expression system and used for immunization of mice to gain the polyclonal antibody and for evaluation of antigenicity by protein array. Also, the antibody against Pv92 was used for subcellular analysis by immunofluorescence assay. The Pv92 protein has a signal peptide and a sexual stage s48/45 domain, and the cysteine residues at the N-terminal of Pv92 were completely conserved. The N-terminal of Pv92 was successfully expressed as soluble form using a bacterial expression system. The antibody raised against Pv92 recognized the parasites and completely merged with PvMSP1-19, indicating that Pv92 was localized on the merozoite surface. Evaluation of the human humoral immune response to Pv92 indicated moderate antigenicity, with 65% sensitivity and 95% specificity by protein array. Taken together, the merozoite surface localization and antigenicity of Pv92 implicate that it might be involved in attachment and invasion of a merozoite to a new host cell or immune evasion during invasion process.

• 폴리머
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• 제38권2호
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• pp.220-224
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• 2014

콘택트렌즈용 하이드로젤로의 단백질 흡착량을 시간에 따라 분석하여 계면으로 확산되는 단백질 흡착 반응속도를 연구하였다. HEMA(hydroxyethylmethacrylate)계열 하이드로젤과 silicone계열 하이드로젤을 단백질(알부민 또는 IgG)용액에 침지시킨 후 단백질 흡착량을 시간에 따라 측정하였다. 모든 하이드로젤로의 단백질 흡착량은 단시간(10분)에 급격히 증가한 후 90분 동안 변화 없이 일정하였다. 빠른 단백질 분자의 확산에도 불구하고 계면에너지 감소는 한 시간 이상 진행되는데 이는 계면 탈수 현상이 한 시간 이상 진행되기 때문으로 이해된다. 계면에너지와 단백질 흡착량의 상관관계를 이해하여 콘택트렌즈 재질로의 단백질 흡착 반응 속도의 메커니즘을 분석하였다.

• 한국식품조리과학회지
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• 제5권2호
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• pp.9-17
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• 1989

This study was carried out in order to study the emulsifying properties of kidney bean protein isolate. Kidney bean protein isolate was tested for the purpose of finding out the effect of pH, addition of NaCl, and heat treatment on the solbulity and emulsion capacity, emulsion stability, surface hydropobicity and emulsion viscosity. The results were summarized as follows. 1 The solubility of kidney bean protein isolate was affected by pH and showed the lowest value at pll 4.5 which is isoelectric point of kidney bean isolate. When the kidney bean protein isolate was heated, the highest value observed at pH 2 and pH 7 was 96.11%, 97.41% respectively. 2. The emulsion capacity of kidney bean protein isolate was not significantly different with each pH. With addition of NaCl, emulsion capacity decreased steadily. When heated thr highest value observed at pH 2 and pH 7 was 82.91 ml oil/100 mg protein ($60^{\circ}C$), 82.08 m1 oil/100 mg protein ($80^{\circ}C$) respectively. 3. The emulsion stability was significantly higher at pH 4.5 than that of pH 2 and pH 7 (p 0.05) When NaCl was added, emulsion stability was generally increased after 2hrs. When heated, the highest value observed at pH 2 and pH 7 was 21.25% ($80^{\circ}C$),23.7%($100^{\circ}C$) respectively after 2hrs. 4. Surface hydrophobicity increased sharply as 0.2 M NaCl was added to pH 4.5. When heated, the surface hydrophobicity increased as the temperature increased. 5. The highest value of emulsion viscosity was observed at pH 4.5 and pH 7 when 0.2 M NaCl was added. Under heat treatment, the highest value was 48,000 cps at pH 4.5 ($40^{\circ}C$). In the case of pH 7, the highest value was 105,000 cpa at $100^{\circ}C$.