• Applied Biological Chemistry
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• v.8
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• pp.11-20
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• 1967

In order to study the change of nitrogeneous compounds during the "Natto" preparation, the contents of insoluble protein, water soluble protein and amino nitrogen were determined and the pattern of peptides and amino acids was investigated by paper chromatography for the fractions resulting from molecular sieving. The results are summarized as follows: 1. Insoluble protein nitrogen which was increased to 84% by autoclaving the native soybean decreased to 44%, whereas the trichloroacetic acid soluble nitrogen increased from 8% to 45% during Natto preparation, But the soluble protein nitrogen showed a slight increase. 2. Fractionation of the peptides using Dowex-50 resins showed that they consisted mostly of lower molecular weight peptides which increased in accordance with the progress of fermentation, especially after 30-hour period. 3. Sixteen known and two unknown amino acids, and three peptides with different Rf values were identified during the Natto preparation. Their appearance showed some difference in that phenylalanine appeared after 10 hours, methionine, after 20 hours and proline, after 30 hours, respectively. The three peptides appeared at the different stage of fermentation.

• Korean Journal of Food Science and Technology
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• v.4 no.1
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• pp.36-43
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• 1972

A survey of the free amino acids and free sugars in tomato, watermelon, muskmelon, peach and plum was made by means of amino acid autoanalyzer and thin layer chromatography. The results of the survey are summarized as follows. 1) Fifteen amino acids found in fruit were aspartic acid, glutamic acid, alanine, serine, asparagine, lysine, valine, glycine, methionine, histidine, threonine, leucine, isoleucine, proline and arginine, and an unknown was found. 2) Ten kinds of amino acids were detected in tomato, peach and plum, thirteen amine acids in watermelon and muskmelon (edible part), and eleven amino acids in muskmelon (rind). 3) In general, these fruits contained similar amounts of these thirteen amino acids, and although they were not outstandingly high in any one acid they did contain a nutritionally well-balanced mixture. 4) Amino acids found in the greatest amount in fruit were following: glutamic acid and aspartic acid in tomato, asparagine and lysine in watermelon, alanine, serine and aspartic acid in musk-melon, and aspartic acid and serine in peach and plum. 5) Glucose, fructose, sucrose and maltose were detected in all fruit. The contents of glucose and fructose were high, and those of sucrose and maltose were low.

• Journal of Korean Society of Forest Science
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• v.43 no.1
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• pp.31-34
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• 1979

In this study, enzymatic hydrolysis of the substrate of the waste wood of Cortinellus edodes was investigated using crude cellulase preparation of Trichoderma viride Pers. ex. Fr. SANK 16374. The crude cellulase was produced by the submerged culture process and produced in the culture fluid was salted out quantitatively by the use of ammonium sulfate. Reducing sugar was determined by the dinitrosalisylic acid (DNS) method. 1. The chemical composition of the waste wood was crude protein 2.26%, c. fat 2.57%, c. fibre 44.60%, c. ash 5.58% and lignin 13.62%. In amino acid composition, no cystine and methionine was showed, but trace amount of Vitamin A, $B_1$, and $B_2$, niacine and chloride were detected. (Table 1) 2. As heat treatment of the substrate was found to produce the highest reducing sugar yield being reacted for 48hr. with T.v cellulase, the substrate was heated to $190{\pm}5^{\circ}C$. for 45 min. either before or immediately after milling. 3. The substrate heated and ball milled at $190{\pm}5^{\circ}C$. for 45 min. the reducing sugar yield reached to 11.5%. 4. The substrate without any treatment was found to produce the highest reducing sugar yield being reacted 72hr. with T. v cellulase, the reducing sugar yield reached to 10.1%. 5. The rate of reducing sugar per each treated substrate was decreased by the order of the substrated, heated and then ball milled at $190{\pm}5^{\circ}C$. for 45 min. (11.5%)> without any treatment (10.1)> ball milled and heated at $190{\pm}5^{\circ}C$. for 45 min. (6.9%). 6. Saccharification of waste wood has been shown to be possible by heat treated and milling the substrate in contact with cellulase. And it is likely to be recommended that the waste wood may be valuable for raw materials of saccharification.

• Korean Journal of Food Science and Technology
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• v.32 no.4
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• pp.902-907
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• 2000

Protamine-strong basic protein was prepared from salmon(chum salmon, Oncorhynchus keta) sperm by several pretreatment method. And there were determined yield, amino acid composition, antimicrobial and antioxidant activity of protamine on each pretreatment condition. The yield of protamine was different according to pretreatment, and ultrasonicating, homogenizing and microwaving pretreatment were about 16.0%, 15.5% and 10%, respectively. The main amino acid of P60(microwaving pretreatment for 10 min at $80^{\circ}C$) and UU6(ultrasonicating pretreatment for 60 min at $20^{\circ}C$) were arginine, proline and tryptophan, and arginine content of P60 and UU6 were 61%, 53%, respectively. On the other hand, main amino acid of M(homogenizing pretreatment by mixer) were methionine, proline and arginine, the content were 34%, 28% and 11%, respectively. Also MC(homogenizing pretreatment with $H_{2}SO_{4}$ soln. by mixer) was very different with P60, UU6 and M, the content of MC were proline 44.8% and arginine 39.7%. Prepared protamines showed antimicrobial activity to several gram(+) and gram(-) strain. In particular, the UU6 and P60 protamine has strong antimicrobial activity to Bacillus subtilis and Escherichia coli, and the activity was increased with concentration increasing. Regardless of pretreatment method, all protamine showed antioxidant activity and the $EDA_{50}$ of P60, UU6, M and MC were $101\;{\mu}g/mL$, $410\;{\mu}g/mL$, $523\;{\mu}g/mL$ and $490\;{\mu}g/mL$, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.12
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• pp.1708-1713
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• 2002

Endometrial explants obtained from does between days 13 and 21 of pregnancy were cultured in a modified minimum essential medium in the presence of [$^35S$]methionine and [$^3H$]-leucine. Proteins synthesized and secreted into medium were analyzed by fluorography of two-dimensional polyacrylamide gel electrophoresis and fluorography. No marked qualitative changes in patterns of protein production by caprine endometrium between days 13-21 of pregnancy. At least 11 proteins showed consistently a clear spot or a grouping of spots with characteristic location on two-dimensional gels. A major low molecular weight protein consisted of two major isoforms (pI 5.3-6.0) of similar molecular mass (21 kDa). Limited N-terminal sequence analysis of these two isoforms showed that the protein had complete homology with bovine placental and plasma retinol-binding protein (RBP) over the first 20 amino acids. Through use of the antiserum raised against bovine placental RBP, immunoreactive RBP was detected in cultures conditioned by uterine explants prepared at days 13, 15 and 21 of pregnancy. In the present study, proteins synthesized and secreted by caprine endometrium during periattachment period of early pregnancy were characterized. The pregnant endometrium secreted a number of neutral-to-acidic proteins which constituted, in part, the histotroph. A vitamin A-transport protein, RBP, was identified in cultures conditioned by endometrium of days 13-21 of pregnancy. The uterine endometrium is the only source of retinol for embryonic tissues. The uterine RBP appears to transport retinol locally toward embryonic tissues. Secretion of RBP by caprine endometrium of days 13, 15 and 21 of pregnancy suggested that retinol played an important role in conceptus development during periattachment period of early pregnancy.

• Korean Journal of Microbiology
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• v.29 no.1
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• pp.16-24
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• 1991

The yeast gene THR1 encodes the homoserine kinase (EC 2.7.1.39: HKase) which catalyses the first step of the threonine specific arm at the end of the common pathway for methionine and threonine biosynthesis. A recombinant plasmid pMC3 (12.6 kilobase pairs, vector YCp50) has been cloned into E. coli HB101 from a yeast genomic library through its complementing activity of a thr1 mutation in a yeast recipient strain M39-1D. When subcloned into pMC32 (8.6kbp, vector YRp7) and pMC35 (8.3 kbp, vector YIp5), the HindIII fragment (2.7 kbp) of pMC3 insery was positive in the thrI complementing activity in both yeast and E. coli auxotrophic strains. The linearized pMC35 was introduced into the original recipient yeast strain and the mitotically stable chromosomal integrant was identified among the transformants. Through the tetrad analysis, the integration site of the pMC35 was localized to the region of THR1 structural gene at an expected genetic distance of approximately 11.1 cM from the ARG4 locus on the right arm of the yeast chromosome VIII. When episomically introduced into the auxotrophic cells and cultured in Thr omission liquid medium, the cloned gene overexpressed the HKase in the order of thirteen to fifteenfold, as compared with a wildtype. HKase levels are repressed by addition of threonine at the amount of 300 mg/l and 1, 190 mg/l for pMC32 and pMC3, respectively. Data from genetic analysis and HKase response thus support that the cloned HindIII yeast DNA fragment contains the yeast thr1 structural gene, along with necessary regulatory components for control of its proper expression.

• Journal of Microbiology and Biotechnology
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• v.30 no.12
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• pp.1905-1911
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• 2020

Homoserine dehydrogenase (HSD) catalyzes the reversible conversion of ʟ-aspartate-4-semialdehyde to ʟ-homoserine in the aspartate pathway for the biosynthesis of lysine, methionine, threonine, and isoleucine. HSD has attracted great attention for medical and industrial purposes due to its recognized application in the development of pesticides and is being utilized in the large scale production of ʟ-lysine. In this study, HSD from Bacillus subtilis (BsHSD) was overexpressed in Escherichia coli and purified to homogeneity for biochemical characterization. We examined the enzymatic activity of BsHSD for ʟ-homoserine oxidation and found that BsHSD exclusively prefers NADP+ to NAD+ and that its activity was maximal at pH 9.0 and in the presence of 0.4 M NaCl. By kinetic analysis, Km values for ʟ-homoserine and NADP+ were found to be 35.08 ± 2.91 mM and 0.39 ± 0.05 mM, respectively, and the Vmax values were 2.72 ± 0.06 μmol/min-1 mg-1 and 2.79 ± 0.11 μmol/min-1 mg-1, respectively. The apparent molecular mass determined with size-exclusion chromatography indicated that BsHSD forms a tetramer, in contrast to the previously reported dimeric HSDs from other organisms. This novel oligomeric assembly can be attributed to the additional C-terminal ACT domain of BsHSD. Thermal denaturation monitoring by circular dichroism spectroscopy was used to determine its melting temperature, which was 54.8℃. The molecular and biochemical features of BsHSD revealed in this study may lay the foundation for future studies on amino acid metabolism and its application for industrial and medical purposes.

• KSBB Journal
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• v.14 no.5
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• pp.578-584
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• 1999

The lectin was purified through 0.15 M NaCl extraction, ammonium sulfate precipitation, sepharose 4B affinity chromatography and gel filtration using sephadex G-150 from the leaves of Visum album collected in Mt. Duk Yu. The final gel filtration step resulted in 11.64 folds purification with 0.14% of recovery yield. We also performed biochemical characterization of the purified Visum album lectin. HPLC analysis of lectin purified by gel filtration revealed a singel peak. The analysis of the purified lectin by SDS-PAGE showed a tetramer composed of two identical subunits with molecular weights of 32 and 30 kDa. The lectin was a glycoprotein containing 14.4% carbohydrate, which consist of glucose, fructose, arabinose and xylose, and the amino acids such as phenylalanine, lysine and tyrosine. The purified lectin agglutinated human red blood cell types with similar potency, but when tested against red blood cells from mouse, bovine, rabbit, chicken and porcine, significant difference in potency were observed. Hemaggluting activity was inhibited by D-galactose, D-mannose, D-lactose and D-raffinose, but not by D-glucose, D-glucosamine, D-mannosamine, L-fructose, D-xylose, D-arabinose, D-galacturonic acid, D-fructose, L-rhamnose and N-acetyl-D-galactosamine. The optimal pH and thermal stability of the purified lectin were pH 4.0-7.0 and 20-5$0^{\circ}C$, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.3
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• pp.247-252
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• 2002

To prepare the edible film based on fish protein, the optimal conditions for extracting soluble protein from Alaska pollack ( Theragra chalcogramma) and mackerel (Scomber japonious) muscle were defined. The effects of protein concentration, pH and temperature of protein solution on the physical properties of films were also investigated, Contents of moisture, crude protein, crude lipid and ash in Alaska pollack muscle were 79.6, 18.2, 0.6 and $1.2\%$, respectively. Contents of moisture, crude protein, crude lipid and ash in mackerel muscle were 69,1, 20.1, 9,5 and $1.3\%$, respectively. Both soluble protein contents extracted from Alaska pollack and mackerel were the highest at pH 12.0, and then un 2.0, 11.0. But they were extracted a little at neutral range. forward the recovery yield of protein by controlling isoelectric point was the highest at pH 4.8 ($79.8\%$) for Alaska pollack and at pH 5.0 ($64.1\%$) for mackerel, For the preparation of protein films from both Alaska pollack and mackerel, the most effective conditions of film forming solution were achieved, after supplied fish protein 4 g (glycerol 1,6 g) in 100 mL of distilled water, by adjusted to pH 10.0 and then heated at $90^{\circ}C$.

• Korean Journal of Organic Agriculture
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• v.11 no.1
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• pp.67-77
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• 2003

This study was conducted to established method of culture for Paecilomyces japonica using an egg. Mycelia grew favorably at the temperature of 22～26$^{\circ}C$ on eggs. 5.1g of dry matter basis(average 7.2cm of longer and 199.6 of numbers) of artificial fruiting bodies were harvested at 60 days after inoculation from one of egg. Commercial fruiting bodies of Paecilomyces japonica from silkworms was used for comparative nutriental contents. Cordycepin contents of fruit bodies of Paecilomyces japonica cultivated on eggs and silkworms were not significantly different. Crude fat contents of fruiting bodies of Paeilomyces japonica cultivated from eggs was significantly higher than from silkworms(P<0.05). Mn and Cu contents of fruiting bodies of Paecilomyces japonica cultivated from silkworms were significantly higher than from eggs(P<0.05), but Na, Mg, Fe and Zn contents were significantly higher from eggs(P<0.05). Glycine, Arginine and Proline contents in the fruiting bodies of Paecilomyces japonica cultivated from silkworms were tend to higher than from eggs, but Serine, cystein. methionine, isoleucine and phenylalanin were tend to higher from eggs. These results were made possible that possible mass production of artificial fruiting bodies of Paecilomyces Japonica cultivated on eggs.