• Journal of Sericultural and Entomological Science
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• v.31 no.1
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• pp.37-44
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• 1989

The parasporal crystals of Bacillus thuringinsis subspecies kurstaki, dendrolimus, finitimus, aizawai and israelensis were compared by polyacrylamide electrophoresis, amino acid composition and immunological analysis. In the subspecies of kurstaki, dendrolimus, finitimus and aizawai, the molecular weights of main subusnits of crystal solubilized by alkaline solution were 1.3${\times}$105 and 6.5${\times}$104 while those of subsp. israelensis were 4${\times}$104 and 1,4${\times}$104. The degradation of lepidopteran toxic subspecies crystals by silkworm midgut protease showed 6.0-6.4${\times}$104 molecular weight and the pattern of degradation of subsp. israelensis crystals was similar to that of alkaline solution treatment. In the amino acid composition, aspartic acid in subsp. israelensis and glutiamic acid in the other four subspecies were the most abundant. The immunological characteristics of the crystals revealed that the antibody produced against the alkali-solubilized crystal protein of subsp. israelensis reacted with only its antigen, but the crystal antigens from the other four lepidopteran toxic subspecies did cross-react with each other as well as with their own homologous antisera.

• Korean Journal of Food Science and Technology
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• v.17 no.6
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• pp.442-446
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• 1985

The changes of nitrogen utilization ratio (NUR), Protein solution ratio (PSR) and free sugar contents during the amino acid soysauce manufacturing process by a low hydrochloric acid, temperature were investigated. On hydrolysis by 6%-HCI (3 liquor rate of defatted soybean weight, 3LR) at $85^{\circ}C$, NUR and PSR were 74.51%, 56.49% at 65 hours. At the same time free sugars were detected glucose, galactose, arabinose, fructose, xylose. on hydrolysis at $95^{\circ}C$, NUR and PSR were 77.72%, 64.04% at 50 hours, and 5 free sugars of the above statement were detected at 5 hours. Remarkable decreases in the levels of free sugars, only glucose were observed after 80 hours of the hydrolysis. On hydrolysis by 12%-HCI(3LR) at $95^{\circ}C$, NUR and IRA were 88.41%, 69.47% at 50 hours, free sugar were nearly disappeared after 20-35hours. On hydrolysis, galactose's disappearence rate was faster than glucose's.

• Journal of Life Science
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• v.15 no.4 s.71
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• pp.633-640
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• 2005

The purified xylanase from Bacillus pumilus TX703 was modified with various chemical modifiers to determine the active sites of the enzyme. Treatment of the enzyme with group-specific reagents such as carbodiimide or N-bromosuccinimide resulted in complete loss of enzyme activity. These results assumed that these reagents reacted with glutamic acid or aspartic acid and tryptophan residues located at or near the active site. In each case, inactivation was performed by pseudo first-order kinetics. Inhibition of enzyme activity by carbodiimide and W-bromosuccinimide showed non-competitive and competitive inhibition type, respectively. Addition of xylan to the enzyme solution containing N-bromosuccinimide prevented the inactivation, indicating the presence of tryptophan at the substrate binding site. Analysis of kinetics for inactivation showed that the loss of enzyme activity was due to modification of two glutamic acid or aspartic acid residues and single tryptophan residue.

• International Journal of Industrial Entomology and Biomaterials
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• v.27 no.1
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• pp.203-208
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• 2013

Sericin is usually abandoned after the degumming process. However, it could be a valuable bioresource if an economically efficient recovery process could be set up. In this study, sericin was recovered directly from the degummed waste solution by adding calcium chloride, which induced the precipitation of the surfactant, sodium oleate, by charge interaction. The recovery yield was maximum when 10% of calcium chloride was added. Further increase in the calcium chloride concentration induced the precipitation of sericin. The recovered sericin had a molecular weight distribution similar to that of the hot-water-extracted sericin; but some highmolecular- weight sericin could not be recovered. The secondary structure and amino acid composition of the recovered sericin were similar to those of conventional hot-water-extracted sericin. We expect that sericin recovered from the degummed waste solution could be an alternative to the hot-water-extracted sericin, which is widely used in various applications.

• 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.

• Journal of the Korean Magnetic Resonance Society
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• v.9 no.2
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• pp.74-92
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• 2005

The high resolution solution structure of MCP-3 was determined using multinuclear, multidimensional NMR spectroscopy with an expressed and $^{13}C-\;and\;^{15}N-labeled$ protein. The MCP-3 has a typical chemokine fold including 3 anti-parallel $\beta-sheets$, and a C-terminal helix, but it exists as a monomer in solution under the conditions where the structure was determined (2 mM, pH 5.1 at $30^{\circ}C$). Based on the structure and the amino acid sequence compared to other chemokines we propose that Ile20 and Leu25 in MCP-3 play key roles in the formation of N-loop (residues between the $2^{nd}$ cysteine and the I sheet) which has been implicated as a determinant of chemokine specificity. Additional receptor binding surface is supplied by the 40s loop (residues between the 2 and the 3 sheet) and the binding interface of the acidic N-terminal region of chemokine receptor to MCP-3 would resemble the dimerization interface of CC type dimer.

• Bulletin of the Korean Chemical Society
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• v.19 no.1
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• pp.57-62
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• 1998

We have synthesized a 17-residue peptide with the amino acid sequence RQMKEDAKGKSEEELAD corresponding to residues 84-100 of chicken skeletal troponin C. This stretch of the protein sequence is in the middle one-third of the 32-residue 9-turn α-helix that connects the two globular domains of the dumbell-shaped molecule and includes the D/E linker helix. We describe here the solution conformation of the helix linker as studied by circular dichroism (CD) and two-dimensional nuclear magnetic resonance (2-D NMR) spectroscopy. The NOE connectivities together with the vicinal $^3J_{N{\alpha}}$ coupling constants suggest that the peptide exists in a fast conformational equilibrium among several secondary structure: a nascent helix near the N-terminus, a helix, and a substational population of extended and random coil forms. In addition, two interresidue α-α NOEs are observed suggesting a bent structure with a bend that includes the single glycine in position 92. These results are consistent with the ideas that in neutral solution the D/E linker region of the central helix in troponin C can adopt a helical conformation and the central helix may have a segmental flexibility around Gly 92.

• Food Science of Animal Resources
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• v.38 no.4
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• pp.679-692
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• 2018

The effects of high-pressure processing (HPP) treatment on the quality characteristics of low graded Hanwoo beef marinated with five different sauces (soy, fish, fish-soy, soy-fish and fish-soy-meat sauces) obtained from Asian countries were studied. The Hanwoo beef striploins were marinated with the aforementioned sauces (at ratio: 3:1 w/w) for 3 days at $4^{\circ}C$ before they were treated with HPP at 550 MPa for 5 min at $10^{\circ}C$. All the sauces used were equalized to a same salt level of 12.5%, and the samples marinated with a 12.5% brine solution were served as a control. After treating with the HPP, all the samples were stored for further 7 days at $4^{\circ}C$ for analyses. Results revealed that HPP treatments showed some effects on technological quality traits (pH, cooking loss and color) but had no effect on the collagen contents of the marinated beef. Noticeably, the HPP treatment led to the increases in amounts of free amino acids associated with monosodium glutamate-like taste and sweet taste in the samples marinated with fish sauce or soy-fish sauce, fish-soy sauce and fish-soy-meat sauce whereas, it only reduced these amino acids in the samples marinated with soy sauce or control. Furthermore, the total bacteria count in all the marinated beef samples treated with HPP were significantly (p<0.05) lower than those of the non-HPP-treated samples throughout the storage periods. It is concluded that HPP could be applied for enhancing the taste-active compounds production such as free amino acids, and improving the shelflife stability of the marinated beef.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.5
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• pp.433-441
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• 1995

A series of experiments was conducted to determine the influence of various pepsin-HCL pretreatment factor, hereby the factors of duration of washing for the retrieved bags, inherent to the mobile nylon bag technique (MNBT), on apparent ileal digestibility of crude protein (AIDCP) and apparent ileal digestibility of dry matter (AIDDM). At last, the AIDCP and apparent ileal digestibility of amino acids (AIDAA) in maize, barley, wheat, rapeseed meal, cottonseed meal and three mixed diets were determined with the MNBT and ileo-rectal anastomis pigs (IRAT). For the MNBT techniques, bag measuring $25{\times}40$ MM and containing 0.75 g feedstuff samples, after pre-digestion in vitro, were introduced into the ileo-rectal anastomis pigs (IRAT) gastrointestinal tract through a duodenal cannula and recovered in the ileal digesta between 6 and 12 h. later. 1. The apparent ileal digestibility of dry matter (AIDDM) and crude protein (AIDCP) of the tested samples, with the exception of fish meal, determined by MNBT were not affected by the different pepsin-HCL pretreatment times in vitro between 2.5 h. and 4 h. 2. There was no significant (p > 0.05) difference of the AIDCP and AIDDM of maize determined by the MNBT among different pepsin concentration (0.03%, 0.07% and 0.1 %) treatment in vitro. 3. The AIDCP determined with the MNBT was affected by the washed and unwashed recovered bags from the ileal digesta. 4. The AIDCP and AID amino acids (AIDAA) of maize, barley, wheat, rapeseed meal, soya-bean meal, cottonseed meal and three mixed diets from the MNBT, with a solution of 0.01N HCL (PH 2) and 0.1% of pepsin concentration, a pepsin-HCL pretreatment time in vitro or 4h. and a washing time of the recovered bag from the ileal digesta compared well with those from the IRAT. The linear regression analysis showed a significant correlation (p < 0.01) of AIDCP and AIDDA between the IRAT and MNBT.

• Journal of the East Asian Society of Dietary Life
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• v.16 no.1
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• pp.99-106
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• 2006

New application of rice was carried out by coating the rice with the mixture solution of ginseng and chungkukjang water extract The physicochemical characteristics of the coated rice were investigated. Moisture content of uncoated (15.26%) and coated rice$(15.57\sim15.66%)$ was not different significantly. The contents of crude protein, crude fat, and crude ash of the coated rice were higher as much as $4.28\sim11.82%\;8.47\sim47.46%$, and $11.54\sim42.31%$ than those of control, respectively. As total free amino acids in coated rice were increased by augmenting the amount of the extract, total free amino acids according to rate was increased to $3.1\sim7.8$ times. The major amino acids in the coated rice was alanine$(19.56\sim39.88\;mg%)$, leucine$(5.14\sim17.66\;mg%)$, and proline$(9.98\sim16.82\;mg%)$. Of those amino acids, alanine and $\gamma-aminobutyric$ acid in only coated rice were detected to the level of $19.56\sim39.88\;mg%$ and $7.78\sim12.36\;mg%$ respectively. The calcium amount of coated rice was increased to 15% to 20%. As increasing the coating rate, hardness, cohesiveness, chewiness, and brittleness of coated rice were decreased, but springiness was increased. Before cooking, the color of coated rice appeared yellow and after cooking turned to the light yellow. The color intensity was increased feasibly as increasing the coating rate. The sensory characteristic of rice coated manufactured by adding 15% of the extract was best and found to be similar to that of the control.