• Korean Journal of Food Science and Technology
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• v.39 no.4
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• pp.438-446
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• 2007

The fermented soybean product, cheonggukjang, is favored by many people, partly due to its bio-functional ingredients. Since the fermentation process of cheonggukjang is mediated by enzymes, including proteases, produced by microbes, analysis of the proteome profile changes in cheonggukjang during fermentation would provide us with valuable information for fermentation optimization, as well as a better understanding of the formation mechanisms of the bio-functional substances. The soluble proteins from cheonggukjang were prepared by a phenol/chloroform extraction method, in order to remove interfering molecules for high resolution 2-D gel analysis. Proteomic analysis of the cheonggukjang different fermentation periods suggested that most of the soluble soy proteins were degraded into smaller forms within 20hr, and many microbial proteins, such as mucilage proteins, dominated the soluble protein fraction. The proteomic profile of cheonggukjang was very different from natto, in terms of the 2-D gel protein profile. Among the separated protein spots on the 2-D gels, 50 proteins from each gel were analyzed by MALDI-TOF MS and PMF for protein identification. Due to database limitations with regard to soy proteins and microbial proteins, identification of the changed proteins during fermentation was restricted to 9 proteins for cheonggukjang and 15 for natto. From de novo sequencing of the proteins by a tandem MS/MS, as well as by database searches using BLASTP, a limited number of proteins were identified with low reliability. However, the 2-D gel analysis of proteins, including protein preparation methods, remains a valuable tool to analyze complex mixtures of proteins entirely. Also, for intensive mass spectrometric analysis, it is also advisable to focus on a few of the interestingly changed proteins in cheonggukjang.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.1
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• pp.35-40
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• 2012

In this study, the effect of degree of milled wax layer on compositions (protein and total dietary fiber content), Alkali Digestion Value (ADV), and texture (hardness, stickiness, toughness, and adhesiveness) with brown rice was investigated. For all the rice cultivars, $Baegjinju$, $Keunnun$, $Samkwang$, and $Seolgaeng$, protein content decreased significantly as the degree of pericarp milling increased ($p$<0.05). Total dietary fiber (TDF) content for $Keunnun$ (9.56%${\rightarrow}$8.09%) and $Samkwang$ (8.05%${\rightarrow}$7.06%) significantly decreased with the degree of removed wax layer. ADV was not affected by being removed wax layer, but ADV of $Samkwang$ was increased from 3.56 to 6.78. As the degree of removed wax layer increased (0%${\rightarrow}$10%), hardness and toughness of cooked brown rice were decreased but stickiness and adhesiveness was increased. The ratio of adhesiveness to hardness was increased with decreased wax layer of brown rice. Accordingly, It suggests that the regulation of the wax layer with brown rice was effected texture of cooked brown rice. The milling technology in wax layer of brown rice is that might be thought to be very useful in rice processing industry.

• Parasites, Hosts and Diseases
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• v.34 no.2
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• pp.135-142
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• 1996

Antigenic domain of jai or surface protein (p30) of Toxoplosmc Sondii was analyzed after polymerase chain reaction (PCR) of its gene fragments. Hydrophilic or hydrophobic moiety of amino acid sequences were expressed as glutathione S-transferase (G57) fusion proteins. Fragments of p30 gene were as follows: 737, total p30 open reading frame (ORF) ; S28, total ORF excluding N-terminal signal sequence and C-terminal hydrophobic sequence; Al9, N-terminal 2/3 parts of A28; A19, N-terminal 2/3 of S28; P9, C-terminal 2/3 part of S28; Z9. middle 1/3 of S28; and 29, C-terminal 1/3 of S28. respectively. Primer of each fragment was synthesized to include clamp sequence of EcoR I restriction site. PCR amplified DNA was inserted info GST (26 kDa) expression vector, PGEX-47-1 to transform into Escheri,hia coei (.JM105 strain). G57 fusion proteins were expressed with IPTG induction as 63. 54, 45, 45, 35, 36. and 35 kDa proteins measured by SDS-PAGE. Each fusion protein was confirmed with G57 detection kit. Western blot analysis with the serum of a toxoplasmosis patient revealed antigenicity in proteins expressed by T37. S28, and Al9 but not those by Pl8. X9, Y10, and Z9. Antigenicity of p30 seems to be located either in N-terminal 115 part in the presence of middle 1/3 part or in the oligopeptides between margins of the first and second 1/3 parts.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.10
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• pp.1638-1641
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• 2005

In order to develop novel food products or additives using transglutaminase (TGase), some physicochemical and morphological understandings are needed. Raw skim milk was adjusted to pH 5.5, 7.0, and 8.5, and each was treated with microbial TGase for 0, 1, 2, 4, and 8 hours, for the protein structure observation using scanning electron microscope (SEM), The particles of untreated raw skim milk were small and evenly associated. After adjustment of pH to 5.5 and treatment of TGase for 1-hour, the protein particles aggregated widely in a bigger form than that of control. Under the same condition for 2 hours, the particles associated and clustered. The particles gathered widely and became a number of small spherical forms after 4 hours. After 8 hours, they made larger forms than the result of 1-hour treatment, and the aggregation broadened. Under the pH 7.0 and 8.5 conditions with TGase-treatment, the protein Particles fractionated and associated into the bigger masses at 1 hour point, but each piece slowly became smaller and more fractionated until treated time reached 4 hours. After 8 hours, the fragmented protein particles aggregated into larger forms as those on the pH 5.5 condition. In general, the electron microscopical forms of the samples adjusted to pH 5.5 showed smaller than those of pH 7.0 or pH 8.5, It is suggested that the protein particles and textural behavior were influenced by pH, TGase, and reaction time.

• The Korean Journal of Ecology
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• v.22 no.1
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• pp.39-43
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• 1999

Serratia marcescens, an enterobacterium of gram-negative bacteria, is characterized by resistance of the admium. Cadmium sensitive PM strain did not grow in the medium at cadmium concentration of 50 ppm. PA strain was induced to accommodate to cadmium by cultivating the mother strain (PC strain) in the medium with 50 ppm cadmium. As compared with PC and PM strains, PA strain revealed the excellent growth in cadmium media and accumulated four to five times higher cadmium concentration in cell than other strains. PA strain accumulated 23% of cadmium in cells when cultured in medium treated with 100 ppm cadmium and this cadmium was more accumulated in cytosol fractions than membrane fractions. Analysis by TEM indicated that cadmium was concentrated as a form of granule in cytosol. In protein patterns of cell after the treatment of cadmium, two inducible proteins (28 KDa and 64 KDa) and one reducible protein (45 KDa) were detected by SDS-PAGE. By Atomic Absorption Spectrophotometer, the amounts of cadmium attached to inducible proteins of 28 KDa and 64 KDa were 318.28 ㎍ and 325.37 ㎍ per gram of protein, respectively. It is assumed that these inducible proteins play an important role in the mechanism of cadmium accumulation in cells. A plasmid of 23Kbp was found in S. marcescens. The ability of resistance to cadmium in plasmid was confirmed by curing experiments.

• Korean Journal of Microbiology
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• v.47 no.3
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• pp.200-208
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• 2011

Most problematic antibiotic resistance mechanism for MLS (macrolide-lincosamide-streptogramn B) antibiotics encountered in clinical practice is mono- or dimethylation of specific adenine residue at 2058 (E. coli coordinate) of 23S rRNA which is performed by Erm (erythromycin ribosome resistance) protein through which bacterial ribosomes reduce the affinity to the antibiotics and become resistant to them. ErmSF is one of the four gene products produced by Streptomyces fradiae to be resistant to its own antibiotic, tylosin. Unlike other Erm proteins, ErmSF harbors idiosyncratic long N-terminal end region (NTER) 25% of which is comprised of arginine well known to interact with RNA. Furthermore, NTER was found to be important because when it was truncated, most of the enzyme activity was lost. Based on these facts, capability of NTER peptide to inhibit the enzymatic activity of ErmSF was sought. For this, expression system for two different proteins to be expressed in one cell was developed. In this system, two plasmids, pET23b and pACYC184 have unique replication origins to be compatible with each other in a cell. And expression system harboring promoter, ribosome binding site and transcription termination signal is identical but disparate amount of protein could be expressed according to the copy number of each vector, 15 for pACYC and 40 for pET23b. Expression of NTER peptide in pET23b together with ErmSF in pACYC 184 in E. coli successfully gave more amounts of NTER than ErmSF but no inhibitory effects were observed suggesting that there should be dynamicity in interaction between ErmSF and rRNA rather than simple and fixed binding to each other in methylation of 23S rRNA by ErmSF.

• Analytical Science and Technology
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• v.27 no.2
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• pp.92-99
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• 2014

Interferences were removed using anion exchange solid phase extraction (AE SPE) in quantification of selenoproteins in Korean human blood serum with affinity high performance liquid chromatography (AF HPLC)-inductively coupled plasma/mass spectrometry (ICP/MS). The average selenium level obtained for healthy Koreans was $94.3{\pm}2.3ngg^{-1}$ using isotope dilution method. AE SPE was coupled to AF column to separate 3 selenoproteins, glutathione peroxidase GPx, selenoprotein SelP, and selenoalbumin SeAlb. Post column isotope dilution was employed to quantify the proteins. The certified reference material of human blood serum BCR-637 was analyzed to give total selenoprotein concentration of $85.4{\pm}3.4ngg^{-1}$, which agreed well with the reference value of $81{\pm}7ngg^{-1}$. The pooled concentration of GPx, SelP, and SeAlb from healthy Koreans (n=20) was $12.1{\pm}1.4ngg^{-1}$, $57.2{\pm}2.0ngg^{-1}$, and $20.0{\pm}1.9ngg^{-1}$, respectively. The sum of selenoproteins is $89.3ngg^{-1}$, which is about the same as the total selenium concentration of $94.3ngg^{-1}$. The fact suggests that selenium in blood serum is mostly consisted of selenoproteins. After the removal of interference, GPx showed a significant decrease (more than 50%) from $25.0ngg^{-1}$ to $12.1ngg^{-1}$. It was identified that the interference in blood serum was mostly from GPx and the use of AE SPE was proven to be efficient in eliminating Cl and Br that cause interference to GPx.

• Applied Chemistry for Engineering
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• v.24 no.5
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• pp.558-561
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• 2013

In the present work, we constructed a recombinant Escherichia coli with cytoplasmic-expressed phosphate-binding protein (PBP) and investigated its phosphate removal in water phase. When the recombinant bacteria were cultured for 6 h to treat phosphate, the removal efficiencies were 90, 49, and 41% for the treatment of 1.0, 1.5, and 2.0 mg/L phosphate, respectively, indicating good specific phosphate removal of our developed system. Also, cell densities of 2.5 and 5.0 Optical density resulted in high phosphate removal efficiencies and ~80% of 2.0 mg/L phosphate was efficiently removed. A novel biotechnology developed in this study could be effectively employed for resolving eutrophication problem in water body.

• Korean Journal of Food Science and Technology
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• v.26 no.2
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• pp.127-132
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• 1994

Removal of viscous materials, mainly alginate, from sea tangle extracts by $CaCl_2$ precipitation or ultrafiltration was investigated. The sea tangle extracts were prepared by enzymatic hydrolysis of polysaccharides followed by 2 hours of boiling in 1.5% NaCl or 2.0% sucrose solution. The $CaCl_2$ precipitation resulted in higher amount of total solid, amino-nitrogen and mannitol than those values of ultrafiltration, but protein extracted was less in the former. Both methods caused a significant decrease in the viscosity and turbidity of the extracts. The composition of four nucleotides showed that UMP and IMP were not detected in $CaCl_2$ precipitated extracts, while ultrafiltered extracts showed a fairly even distribution of them. Removal of viscous material, particularly ultrafiltration increased the glutamic acid in amino acid composition and reduced serine, histidine, lysine, glycine, phenylalanine and leucine.

• KSBB Journal
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• v.18 no.4
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• pp.301-305
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• 2003

The study of pancreatin extraction was investigated by supercritical fluid process. Using supercritical carbon dioxide extraction with entrainer the purification of pancreatin was possible to remove lipids from Hog pancreas. To observe the optimum conditions different experimental variables were changed as pressure, temperature, flow rate of solvent and 0.25 mm of sample size were evaluated for effective removal of lipids. Ethanol and n-hexane were used as an entrainer with 5 mL/min. Increasing pressure at constant temperature the efficiency of the lipid removal in Hog pancreas was improved and the protein was concentrated without denaturalization, compared that of the control Hog pancreas. The most efficient conditions of lipid elimination were 17 MPa of pressure and 35$^{\circ}C$ of temperature and 0.25 mm of sample size.