• Journal of Microbiology and Biotechnology
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• v.18 no.4
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• pp.658-662
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• 2008

Effects of pH shock on the secretion system of S. coelicolor A3(2) have been investigated at a transcriptional level by using DNA microarrays. Actinorhodin secretion was observed to be highly enhanced when an acidic-pH shock was applied to surface grown cultures of S. coelicolor A3(2). In this culture, a gene of actVA-orf1 encoding a putative efflux pump or transporter protein for actinorhodin was strongly upregulated. A major number of efflux pumps for other metabolites and a major number of secretion proteins for protein secretion were also observed to be upregulated with pH shock. The secretion of actinorhodin was observed to be remarkably enhanced in liquid culture as well.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.8
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• pp.1083-1088
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• 2012

The breeding value of marbling score in skeletal muscle is an important factor for evaluating beef quality. In the present study, we investigated proteins associated with the breeding value of the marbling score for bovine sirloin to select potential biomarkers to improve meat quality through comparative proteomic analysis. Proteins isolated from muscle were separated by two-dimensional gel electrophoresis. After analyzing images of the stained gel, seven protein spots for the high marbling score group were identified corresponding to changes in expression that were at least two-fold compared to the low marbling score group. Four spots with increased intensities in the high marbling score group were identified as phosphoglycerate kinase 1, triosephophate isomerase, acidic ribosomal phosphoprotein PO, and capping protein (actin filament) Z-line alpha 2. Spots with decreased intensities in the high marbling score group compared to the low score group were identified as 14-3-3 epsilon, carbonic anhydrase II, and myosin light chain 1. Expression of myosin light chain 1 and carbonic anhydrase 2 was confirmed by Western blotting. Taken together, these data could help improve the economic performance of cattle and provide useful information about the underlying the function of bovine skeletal muscle.

• Biomolecules & Therapeutics
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• v.21 no.1
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• pp.1-9
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• 2013

Polyamines, putrescine, spermidine and spermine, are ubiquitous in living cells and are essential for eukaryotic cell growth. These polycations interact with negatively charged molecules such as DNA, RNA, acidic proteins and phospholipids and modulate various cellular functions including macromolecular synthesis. Dysregulation of the polyamine pathway leads to pathological conditions including cancer, inflammation, stroke, renal failure and diabetes. Increase in polyamines and polyamine synthesis enzymes is often associated with tumor growth, and urinary and plasma contents of polyamines and their metabolites have been investigated as diagnostic markers for cancers. Of these, diacetylated derivatives of spermidine and spermine are elevated in the urine of cancer patients and present potential markers for early detection. Enhanced catabolism of cellular polyamines by polyamine oxidases (PAO), spermine oxidase (SMO) or acetylpolyamine oxidase (AcPAO), increases cellular oxidative stress and generates hydrogen peroxide and a reactive toxic metabolite, acrolein, which covalently incorporates into lysine residues of cellular proteins. Levels of protein-conjuagated acrolein (PC-Acro) and polyamine oxidizing enzymes were increased in the locus of brain infarction and in plasma in a mouse model of stroke and also in the plasma of stroke patients. When the combined measurements of PC-Acro, interleukin 6 (IL-6), and C-reactive protein (CRP) were evaluated, even silent brain infarction (SBI) was detected with high sensitivity and specificity. Considering that there are no reliable biochemical markers for early stage of stroke, PC-Acro and PAOs present promising markers. Thus the polyamine metabolites in plasma or urine provide useful tools in early diagnosis of cancer and stroke.

• Bulletin of the Korean Chemical Society
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• v.31 no.12
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• pp.3521-3524
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• 2010

MTH1880 is a hypothetical protein derived from Methanobacterium thermoautotrophicum, thermophilic methanogen. The solution structure determined by NMR spectroscopy showed that it has a novel $\alpha+\beta$-fold with a highly acidic ligand binding pocket. Since MTH1880 maintains its ultra-stable structural characteristics at both high temperature and pressure, it has been considered as an excellent model for studying protein folding. To initiate the structural and folding study of MTH1880 in proving its unusual stability, we performed the site directed mutagenesis and biochemical analysis of MTH1880 mutants. Data from circular dichroism and NMR spectroscopy suggest that the point mutations perturbed the structural stability of protein even though the secondary structure is retained. This study will provide the useful information in understanding the role of participating residues during folding-unfolding process and our result will be used in designing further folding experiments for hyper-thermopile proteins like MTH1880.

• Molecules and Cells
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• v.42 no.10
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• pp.729-738
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• 2019

Autophagy is an important process for protein recycling. Oligomerization of p62/SQSTM1 is an essential step in this process and is achieved in two steps. Phox and Bem1p (PB1) domains can oligomerize through both basic and acidic surfaces in each molecule. The ZZ-type zinc finger (ZZ) domain binds to target proteins and promotes higher-oligomerization of p62. This mechanism is an important step in routing target proteins to the autophagosome. Here, we determined the crystal structure of the PB1 homo-dimer and modeled the p62 PB1 oligomers. These oligomer models were represented by a cylindrical helix and were compared with the previously determined electron microscopic map of a PB1 oligomer. To accurately compare, we mathematically calculated the lead length and radius of the helical oligomers. Our PB1 oligomer model fits the electron microscopy map and is both bendable and stretchable as a flexible helical filament.

• Food Science of Animal Resources
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• v.37 no.2
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• pp.162-167
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• 2017

Functional and nutritional soluble proteins can be recovered from surimi (and surimi-like material) processing wastewater, reducing environmental problems and the cost of an irresponsible waste disposal. Recovered proteins may be added back at a low percentage to surimi products. The aim of this work was to evaluate the effect of the addition of soluble recovered proteins (RP), obtained from mechanically separated chicken meat surimi-like material (MSCM-SLM) processing wastewater by acidic pH-shifting, on the composition and texture of RP-MSCM-SLM, with RP contents of 0, 10, 20 and 30% (w/w) in the mixture. For that, proximate composition and gel properties were evaluated. The fat content of the MSCM-SLM was significantly reduced to 11.98% and protein increased to 83.64% (dry basis) after three washing cycles. The addition of 30% RP in the MSCM-SLM significantly augmented the protein content to 93.45% and reduced fat content from to 2.78%. On the other hand, the addition of RP was responsible for a drastic decrease in texture parameters, reaching 252.36 g, 185.23 g.cm, and 6.97 N for breaking force, gel strength and cutting strength, respectively, when 30% of RP was included in the MSCM-SLM. It was concluded that the obtained intermediary product (RP-MSCM-SLM) is a good option to applications in processed meat products where high texture parameters are dispensable, e.g., emulsified inlaid frankfurter-type sausages, but high protein content and low fat content desired.

• Journal of Microbiology and Biotechnology
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• v.25 no.2
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• pp.280-287
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• 2015

Current influenza vaccines are produced in embryonated chicken eggs. However, egg-based vaccines have various problems. To address these problems, recombinant protein vaccines have been developed as new vaccine candidates. Unfortunately, recombinant proteins frequently encounter aggregation and low stability during their biogenesis. It has been previously demonstrated that recombinantly expressed proteins can be greatly stabilized with high solubility by fusing stabilizing peptide (SP) derived from the C-terminal acidic tail of human synuclein (ATS). To investigate whether SP fusion proteins can induce protective immunity in mice, we produced influenza HA and SP fusion protein using a baculovirus expression system. In in vitro tests, SP-fused recombinant HA1 (SP-rHA1) was shown to be more stable than recombinant HA1 (rHA1). Mice were immunized intramuscularly with baculovirus-expressed rHA1 protein or SP-rHA1 protein ($2{\mu}g/mouse$) formulated with aluminum hydroxide. Antibody responses were determined by ELISA and hemagglutination inhibition assay. We observed that SP-rHA1 immunization elicited HA-specific antibody responses that were comparable to rHA1 immunization. These results indicate that fusion of SP to rHA1 does not negatively affect the immunogenicity of the vaccine candidate. Therefore, it is possible to apply SP fusion technology to develop stable recombinant protein vaccines with high solubility.

• Applied Biological Chemistry
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• v.25 no.4
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• pp.248-251
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• 1982

Commassie blue G250 produced metachromatic effect with some solvents. The absorptivity and molar absorptivity of the dye in ethanol were 82.4 and $70.4{\times}10^3$ at maximum absorption wavelength 610nm, respectively. The dye had a red from$({\lambda}_m=465nm)$ in ethanol-phosphoric acid-water solution and converted to a blue form$({\lambda}_m=590nm)$ after binding to protein. Absorbance at 590nm gave linear responses with respect to protein contents. The dye-binding capacities of proteins varied considerably with the content and source of proteins. Under the experimental condition the dye-binding capacities of bovine serum albumin, cytochrome C and ${\gamma}-globulin$ were 110, 103, and $88{\mu}g$ commassie blue G250 bound per $100{\mu}g$ protein, respectively.

• KSBB Journal
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• v.14 no.6
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• pp.677-681
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• 1999

Purificationi of egg yolk immunoglobulin(IgY) was performed to understand the property of egg immunoglobulin. IgY differs from mammalian IgY in the molecular size(larger), isoelectric point(more acidic), and binding ability with mammalian complement and protein A(nonbinding ability). IgY is also known as ${\gamma}$-livetin and exists in egg yolk together with other two water-solubel proteins, ${\alpha}$-livetin(chicken serum albumin) and ${\beta}$-livetin(${\alpha}_2$-glycoprotein) and various lipoproteins(Low density lipoprotein, LDL and High density lipoprotein, HDL) which are the major components of egg yolk. The first step of isolation of IgY is to separate the water-solube proteins from lipoproteins. We report a simple method for separation of water soluble proteins using k-carrageenan and sedimentation. k-carrageenan was found to be effective for removal of yolk lipoprotein as a precipitate. IgY remained supernatant, and was isolated by chromatography on columns of DEAE-Sephacel and G 75 gel filtration chromatography.

• Korean Journal of Food Science and Technology
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• v.25 no.4
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• pp.360-365
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• 1993

This study was carried out to examine the effects of phytate addition on the solubility and digestibility of the low-phytate soy protein isolate (LSPI) and high-phytate soy protein isolate (HSPI). In SDS-polyacrylamide gel electrophoresis of soy protein isolate, different patterns of proteins were observed in both HSPI and LSPI at various phytate and pH levels, suggesting that phytate may bind specifically to certain protein fractions at a particular pH. For example, proteins of M.W $1.8{\sim}3.5\;kDa$ resisted phytate binding at acidic pH. LSPI was fractionated into albumin, globulin, gliadin and glutelin, and phytate was shown to bind with difficultly to all three gliadin bands. Effects of phytate on the pepsin digestibility of soy proteins were apparent, especially in the short term digestion.