• Bulletin of the Korean Chemical Society
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• v.27 no.3
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• pp.386-388
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• 2006

Membrane proteins in highly oriented lipid bilayer samples are useful for membrane protein structure determination. We used in the past planar lipid bilayers which were aligned and supported on the glass slide. These samples were mechanically aligned in a magnetic field. However, these stacks of glass slides with planar lipid bilayers are not well suited for use with a commercial solid-state NMR probe with a round coil. Therefore, a homebuilt solid-state NMR probe was built and used with a stack of thin glass plates wherein the RF coil was wrapped directly around the flat square sample. Recently, we began to use magnetically aligned bicelles that are suitable for the structure determination of membrane proteins by solid-state NMR spectroscopy without any effort to build a flat square coil probe. These bicelle samples are well suited for use with a commercial solidstate NMR probe with a round coil, are very easy to prepare and are very stable, so that they can be kept for more than a year. In this paper, we present the solid-state NMR spectra of optimized and magnetically oriented bicelle samples of membrane proteins.

• Preventive Nutrition and Food Science
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• v.7 no.3
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• pp.287-292
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• 2002

The effect of cooking methods on in vivo and in vivo indices of the protein quality of hagfish meat were investigated. In vivo protein digestibilities of cooked meats (81.3~83.5 %) were not significant different (p<0.05) from those of van meat (82.9%), with the exception of steamed (11$0^{\circ}C$, 15 min) meat (86.3 %). Convection oven cooking (22$0^{\circ}C$, IS min) resulted in a higher trypsin indigestible substrate (TIS, 49.2 mg/g solid) compared with that of raw meat (38.9 mg/g solid). free amino acid content of raw meat was decreased after boiling (10$0^{\circ}C$, 10min). Both convection oven and microwave cooking (2,450 MHz, 3 min) decreased available lysine from 4.9g/16g N to 3.8~4.1g/16g N. In vivo apparent protein digestibilites (AD) of hagfish meat were similar fur raw (92.4%) and cooked meats, but were somewhat lower than ANRC (Animal Nutrition Research Council) casein (945%). The PERs (3.7~4.1) and NPRs (3.7~4.9) of cooked meats were significantly higher (p<0.05) than those of raw meat (PER 3.3, NPR 3.6 and ANRC casein (PER 2.5, NPR 2.6), despite their lower in vivo protein digestibilities. These results demonstrate that cooking at optimal conditions resulted in remarkably positive effects on in vivo and in vivo protein qualities of hagfish meats. Therefore, steamed hagfish meat is an excellent source of high quality protein from seafood products.

• Korean Journal of Agricultural Science
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• v.49 no.4
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• pp.1047-1053
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• 2022

The purpose of this study was to compare the effect of solid-state fermentation on soybean using three microbial strains under four different fermentation times. Soybean was fermented for 12, 24, 36 or 48 hours with highly proteolytic microbes, either Bacillus amyloliquefaciens (BA), B. subtilis (BS), or B. subtilis var. natto (BN), and levels of total protein concentration, protein distribution, and antioxidant activity were analyzed. Total protein was highest in the BS 12 h group (9.21 ㎍·µL^-1) and lowest in BN 48 h (6.80 ㎍·µL^-1), respectively (p < 0.001). Furthermore, three microbes decomposed large molecular weight proteins as well as major allergens of soybean such as β-conglycinin, Gly m Bd 30K, and glycinin. Each treatment group showed the highest degradation rate at 48 h fermentation and among the three microbes, BS showed a relatively higher degradation rate. The radical scavenging ability, known as an indicator of antioxidant activity, showed a significant increase in all treatment groups except BA 24 h. The results from this study suggest that protein concentration, and degradation and antioxidant activity were affected by different types of microbial trains and fermentation period and that B. subtilis fermentation might be the most effective way to increase nutritional and functional properties of soybean.

• Proceedings of the Korean Society of Potoscience Conference
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• spring
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• pp.26-27
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• 1996

• YAKHAK HOEJI
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• v.38 no.2
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• pp.158-165
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• 1994

A protein-polysaccaride fraction Kp(53.9% polysaccharide, 14.2% protein) was separated from the shake-cultured mycelia of a basidiomycetous fungus, Phellinus linteus, and its antitumor activity against sarcoma 180 in ICR mice was investigated. When administered after the tumor implantation, Kp exerted antitumor activity by inhibiting the growth of the sarcoma 180 solid tumor by 71.5% and increasing the life span of the sarcoma 180 ascitic mice by 51.5% at 100 mg/kg. In pretreatment tests, in which Kp was administered once daily for 9 days before the tumor implantation, Kp inhibited the growth of the solid and ascites form of sarcoma 180, respectively, by 35.4% and by 80.3% at 100 mg/kg. However, Kp showed no in vitro cytotoxic activity against a murine leukemia L1210 and a human gastric tumor SNU.1 upto the concentration of $200\;{\mu}g/ml$. From these results, it is clear that the antitumor activity of Kp is exerted through its immunomodulating activity on the host's immune system.

• BMB Reports
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• v.32 no.2
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• pp.112-118
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• 1999

The presence of hypoxic cells in solid tumors has long been considered a problem in cancer treatment such as in radiation therapy or treatment with some anticancer drugs. It has been suggested that hypoxic cells are involved in the development of a more aggressive phenotype and contribute to metastasis. In this study, as an attempt to understand how tumor cells adapt to hypoxic stress, we investigated the regulation of the hypoxia-induced expression of proteins that control essential processes of tumor cell survival and angiogenesis. We first examined whether hypoxia induces stress protein gene expression of murine solid tumor RIF cells. We also examined hypoxia-induced changes in angiogenic gene expression in these cells. Finally, we investigated the association of the elevated levels of stress proteins with the regulation of hypoxia-induced angiogenic gene expression. Results demonstrated that hypoxia induced the expression of the erythropoietin (EPO) gene and at least two major members of stress proteins, heat shock protein 70 (HSP70) and 25 (HSP25) in RIF tumor cells. Evidence that the expression of EPO gene was greatly potentiated in TR cells suggested that the elevated levels of HSPs may play an important role in the regulation of the hypoxia-induced EPO gene expression. One of the RIF variant cell lines, TR, displays elevated levels of HSPs constitutively. Taken together, our results suggest that a hypoxic tumor microenvironment may promote the survival and malignant progression of the tumor cells by temporarily increasing the level of stress proteins and expressing angiogenic genes. We suspect that stress proteins may be associated with the increase of the angiogenic potential of tumor cells under hypoxia.

• Applied Biological Chemistry
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• v.33 no.1
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• pp.8-13
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• 1990

The solid and protein yields and extraction properties of color pigments were compared for 7 varieties of soybeans during soaking in water at $4-100^{\circ}C$. The varieties investigated were Paldal, Danyeob, Jangbaek, Baegun, Jangyeob and 2 cultivars of Local 1 and Local 2. The Hunter values showed that Jangbaek was the highest in 'L' value while other varieties except Local 1 and Local 2 were comparatively high in 'L' value. Local 1 and Local 2 were low in 'b' value. The yields of solid and protein during water extraction showed that most of solids and proteins were recovered with three consecutive extractions. The cumulated yields were 73.2 % for solid and 83.2 % for protein. Extraction of color pigments of seed coats in $4-100^{\circ}C$ water showed that the extraction rate was very much dependent on extraction time and temperature. A linear relationship of A=aT+b was obtained for equilibrated absorbance(A) and extraction temperature(T). The activation energy calculated from initial extraction rate of cole. pigments and temperature had two different values of low($4-60^{\circ}C$) and high($60-100^{\circ}C$) temperature range.

• Journal of the Korean Chemical Society
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• v.15 no.4
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• pp.177-181
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• 1971

Free radicals of lysozyme produced by $Ti-H_2O_2$ system were studied in aqueous solution at room temperature using ESR with a continuous flow-mixing. The spectra, each consisting of a doublet with 5.5 G splitting and a broad resonance covering 80 G splitting are closely similar in shape to that for solid irradiated in vacuum at $77^{\circ}K$ and observed at room temperature immediately on warming. The result is assumed to indicate that the secondary protein radical components formed within 0.01 second, dead time of the mixing chamber, and initiated by hydrogen atom abstraction at ${\alpha}$-carbon atom of peptide chain in liquid solution at room temperature are identical to those resulting from the initial formation of a mixture of positive holes and negative ions by ionization processes as well as radical fragments by the rupture of chemical bonds in the solid during similar time at the same temperature. A broad resonance is observed with considerable amplitude on the high field side of the doublet, which is quite dissimilar to the spectra of irradiated solid lysozyme. This resonance was tentatively attributed to the polypeptide free radical in which unpaired electrons are localized on side chain.

• Biomolecules & Therapeutics
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• v.8 no.3
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• pp.235-240
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• 2000

Antitumor effect of LC43, a protein-bound ploysaccharide (M.W. 43 kDa) that was purified from intergeneric protoplast fusant of Lentinus edodes and Coriolus versicolor, was elucidated against mouse sarcoma 180 cell in vitro and in vivo. By injecting LC43 into ICR mice bearing solid or ascitic sarcoma 180, tumor regression and survival rates were investigated. To examine the effects of LC43 on immunopotentiation activity. immunoorgan weight, B cell differentiation, T cell activity and macrophage activation were determined. LC43 showed antitumor effects against both solid tumor and ascitic tumor of sarcoma 180. It did not change significantly the immunoorgan weight but potentiated immune responses such as B cell differentiation and the release of superoxide anion from macrophages. These results suggest that the protein-bound polysaccharide of LC43 exhibited antitumor activities through the activation of immune-related cells and acted as an immunmodulator.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.85-88
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• 2001

We scaled up a covalent immobilization system of urokinase to the activated Sepharose and used it repeatedly to cleave a fusion protein consisting of human growth hormone and GST fragment. After scale up from 6 ml to 250 ml, the column system still demonstrated basically the same performance in terms of urokinase immobilization and fusion protein cleavage. When the column was washed with 6M guanidine HCl after the cleavage reaction. the immobilized urokinase showed no activity probably because it was fully unfolded. However. as the denaturant was gradually removed from the column the immobilized urokinase fully regained its bioactivity. which indicated it was properly refolded into its native conformation as covalently attached to the solid matrix. After 20 cycles of this 'solid-phase unfolding/refolding', the immobilized urokinase maintained approx. 80% of the initial bioactivity. This method provides an efficient protocol to apply the solid-phase refolding technique to improve the longevity of immobilized enzyme columns.