• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.2
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• pp.69-75
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• 2004

In recent years, the importance of proteomic works, such as protein expression, detection and identification, has grown in the fields of proteomic and diagnostic research. This is because complete genome sequences of humans, and other organisms, progress as cellular processing and controlling are performed by proteins as well as DNA or RNA. However, conventional I protein analyses are time-consuming; therefore, high throughput protein analysis methods, which allow fast, direct and quantitative detection, are needed. These are so-called protein microarrays or protein chips, which have been developed to fulfill the need for high-throughput protein analyses. Although protein arrays are still in their infancy, technical development in immobilizing proteins in their native conformation on arrays, and the development of more sensitive detection methods, will facilitate the rapid deployment of protein arrays as high-throughput protein assay tools in proteomics and diagnostics. This review summarizes the basic technologies that are needed in the fabrication of protein arrays and their recent applications.

• Macromolecular Research
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• v.11 no.1
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• pp.53-61
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• 2003

A molecular-thermodynamic model is developed for the salt-induced protein precipitation. The protein molecules interact through four intermolecular potentials. An equation of state is derived based on the statistical mechanical perturbation theory with the modified Chiew's equation for the fluid phase, Young's equation for the solid phase as the reference system and a perturbation based on the protein-protein effective two body potential. The equation of state provides an expression for the chemical potential of the protein. In a single protein system, the phase separation is represented by fluid-fluid equilibria. The precipitation behaviors are simulated with the partition coefficient at various salt concentrations and degree of pre-aggregation effect for the protein particles. In a binary protein system, we regard the system as a fluid-solid phase equilibrium. At equilibrium, we compute the reduced osmotic pressure-composition diagram in the diverse protein size difference and salt concentrations.

• KSBB Journal
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• v.30 no.6
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• pp.296-301
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• 2015

Eggshell-based biocomposites have become attractive due to their exquisite nanostructure and biological properties, which are mainly composed of highly organized calcium carbonate crystals controlled by organic macromolecules such as proteins and polysaccharides. Here, we designed the recombinant fusion protein of a putative eggshell matrix protein named as GG1234 and a fluorescent reporter protein of DsRed. The protein was successfully over-expressed in E. coli and purified by Ni-NTA affinity chromatography. In vitro calcium carbonate crystallization was conducted in the presence of the fusion protein, and morphological change was investigated. The protein inhibited the calcite growth in vitro, and spherical calcium carbonate micro-particles with the diameter of about $20-30{\mu}m$ were obtained. We expect that this study would be helpful for better understanding of eggshell-based biomineralization.

• Journal of Sensor Science and Technology
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• v.20 no.6
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• pp.434-438
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• 2011

A portable surface plasmon resonance(SPR) based immunosensor using thiolated protein G and protein G was developed for the detection of immunoglobulin G(IgG). The protein G has specific affinity with Fc fragment of IgG and was thiolated by 2-Iminothiolane for introduction of thiol groups. Anti-IgG, bovine serum albumin(BSA), and IgG have been sequently injected after surface modification of gold sensor chip with protein G and thiolated protein G. The output signal was increased with the injection of each protein and the actual signal was measured by subtracting signal of reference channel from signal of sample injected channel. The experimental results showed the higher detection capability of IgG using thiolated protein G compared with protein G. From these results, we can conclude that the current surface modification technique and the portable SPR sensor system can be applied to various immunosensors for diagnosis.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.12
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• pp.4897-4902
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• 2014

Purpose: To investigate the anticancer effects and underlying mechanisms of parthenolide on HepG2 human hepatocellular carcinoma cells. Materials and Methods: Cell viability was assessed by MTT assay and cell apoptosis through DAPI, TUNEL staining and Western blotting. Monodansylcadaverin(MDC) and AO staining were used to detect cell autophagy. Cell proliferation was assessed by Ki67 immunofluorescence staining. Results: Parthenolide induced growth inhibition in HepG2 cells. DAPI and TUNEL staining showed that parthenolide could increase the number of apoptotic nuclei, while reducing the expression of the anti-apoptotic protein Bcl-2 and elevating the expression of related proteins, like p53, Bax, cleaved caspase9 and cleaved caspase3. Parthenolide could induce autophagy in HepG2 cells and inhibited the expression of proliferation-related gene, Ki-67. Conclusions: Parthenolide can exert anti-cancer effects by inducing cell apoptosis, activating autophagy and inhibiting cell proliferation.

• Journal of Biomedical Engineering Research
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• v.28 no.5
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• pp.601-608
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• 2007

2 Dimensional Gel Electrophoresis(2DGE) is an essentialmethodology for analysis on the expression of various proteins. For example, information for the location, mass, expression, size and shape of the proteins obtained by 2DGE can be used for diagnosis, prognosis and biological progress by comparison of patients with the normal persons. Protein spot matching for this purpose is comparative analysis of protein expression pattern for the 2DGE images generated under different conditions. However, visual analysis of protein spots which are more than several hundreds included in a 2DGE image requires long time and heavy effort. Furthermore, geometrical distortion makes the spot matching for the same protein harder. In this paper, an iterative algorithm is introduced for more efficient spot matching. Proposed method is first performing global matching step, which reduces the geometrical difference between the landmarks and the spot to be matched. Thus, movement for a spot is defined by a weighted sum of the movement of the landmark spots. Weight for the summation is defined by the inverse of the distance from the spots to the landmarks. This movement is iteratively performed until the total sum of the difference between the corresponding landmarks is larger than a pre-selected value. Due to local distortion generally occurred in 2DGE images, there are many regions in whichmany spot pairs are miss-matched. In the second stage, the same spot matching algorithm is applied to such local regions with the additional landmarks for those regions. In other words, the same method is applied with the expanded landmark set to which additional landmarks are added. Our proposed algorithm for spot matching empirically proved reliable analysis of protein separation image by producing higher accuracy.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.2
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• pp.241-249
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• 2016

The supplementation of livestock feed with animal protein is a present cause for public concern, and plant protein shortages have become increasingly prominent in China. This conflict may be resolved by fully utilizing currently available sources of plant protein. We estimated the rumen degradability and the small intestinal digestibility of the amino acids (AA) in rapeseed meal (RSM), soybean meal (SBM), sunflower seed meal (SFM) and sesame meal (SSM) using the mobile nylon bag method to determine the absorbable AA content of these protein supplements as a guide towards dietary formulations for the dairy industry. Overall, this study aimed to utilize protein supplements effectively to guide dietary formulations to increase milk yield and save plant protein resources. To this end, we studied four cows with a permanent rumen fistula and duodenal T-shape fistula in a $4{\times}4$ Latin square experimental design. The results showed that the total small intestine absorbable amino acids and small intestine absorbable essential amino acids were higher in the SBM (26.34% and 13.11% dry matter [DM], respectively) than in the SFM (13.97% and 6.89% DM, respectively). The small intestine absorbable Lys contents of the SFM, SSM, RSM and SBM were 0.86%, 0.88%, 1.43%, and 2.12% (DM basis), respectively, and the absorbable Met contents of these meals were 0.28%, 1.03%, 0.52%, and 0.47% (DM basis), respectively. Among the examined food sources, the milk protein score of the SBM (0.181) was highest followed by those of the RSM (0.136), SSM (0.108) and SFM (0.106). The absorbable amino acid contents of the protein supplements accurately reflected protein availability, which is an important indicator of the balance of feed formulation. Therefore, a database detailing the absorbable AA should be established.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.3
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• pp.284-288
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• 2005

Baker's yeast was disrupted in a 1.4-L stainless steel horizontal bead mill under a continuous recycle mode using 0.3 mm diameter zirconia beads as abrasive. A single pass in continuous mode bead mill operation liberates half of the maximally released protein. The maximum total protein release can only be achieved after passaging the cells 5 times through the disruption chamber. The degree of cell disruption was increased with the increase in feeding rate, but the total protein release was highest at the middle range of feeding rate (45 L/h). The total protein release was increased with an increase in biomass concentration from 10 to $50\%$(w/v). However, higher heat dissipation as a result of high viscosity of concentrated biomass led to the denaturation of labile protein such as glucose 6-phosphate dehydrogenase (G6PDH). As a result the highest specific activity of G6PDH was achieved at biomass concentration of $20\%$(ww/v). Generally, the degree of cell disruption and total protein released were increased with an increase in impeller tip speed, but the specific activity of G6PDH was decreased substantially at higher impeller tip speed (14 m/s). Both the degree of cell disruption and total protein release increased, as the bead loading increased from 75 to $85\% (v/v)$. Hence, in order to obtain a higher yield of labile protein such as G6PDH, the yeast cell should not be disrupted at biomass concentration and impeller tip speed higher than $20\%(w/v)$ and 10 m/s, respectively.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.2
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• pp.89-93
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• 2003

human renin binding protein (hRnBp), showing N-acetylglucosamine-2-epimerase activity, was over-expressed in E. coli, but was mainly present as an inclusion body. To improve its solubility and activity, ubiquitin (Ub), thioredoxin (Trx), maltose binding protein (MBP) and NusA, were used as fusion partners. The comparative solubilities of the fusion proteins were, from most to least soluble: NusA, MBP, Trx, Ub. Only the MBP fusion did not significantly reduce the activity of hRnBp, but enhanced the stability. The Origami (DE3), permitting a more oxidative environment for the cytoplasm in E. coli; helped to increase its functional activity.

• 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.