• Journal of Microbiology and Biotechnology
• /
• v.11 no.1
• /
• pp.29-34
• /
• 2001

The mutant enzymes of N-carbamyl-D-amino aicd amidohydrolase (N-carbamylase) from Agrobacterium radiobacter NRRL B11291, showing a negligible activity, were selected from the library generated by random mutagenesis. From the sequence analysis, these mutants were found to contain the amino acids substitutions at Cys172, Glu47, and Glu146. Previously, Cys172 was reported to be necessary for the enzyme catalysis. The chemical modification of the N-carbamylase by carboxyl group specific chemical reagent, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide(EDC), resulted in a loss of activity. The replacement of glutamic acids with glutamines by site-directed mutagenesis led to aggregation of the enzymes. Mutant enzymes fused with maltose binding protein (MBP) were expressed in soluble form, but were inactive. These results indicate that two glutamic acid residues play an important role in structure and function of the N-carbamylase. Multiple sequence alignment of the related enzymes revealed that Glu47 and Glu146 are rigidly conserved, which suggests that tese residues are crucial for the structure and function of the functionally related C-N hydrolases.

• Food Science and Preservation
• /
• v.19 no.5
• /
• pp.645-651
• /
• 2012

The food functional properties of Pleurotus eryngii cultivated with different wavelengths of light-emitting diode (LED) light were analyzed in this study. The levels of total soluble solids of Pleurotus eryngii increased with all the LED lights, except mixed LED light ($B^*R$, $B^*G$ and $R^*G$). Thirty one kinds of components were detected by analyzing the free amino acids. The total free amino acid contents had a slightly higher tendency in the control group, but the ratios of eight essential amino acids among the total amino acids of Pleurotus eryngii cultivated under all the LED lights, including the blue light (blue, $B^*R$, $B^*G$ and $B^*R^*G^*U$) and the green light, were higher than that in the control group. K was the highest-content of mineral, and Mn was the lowest-content. The Ca content increased through cultivation under all the LED lights, except the blue light, but the Fe content (under the green and $B^*R$ lights), K content (under the red and UV-A lights) and Mg content (under the $R^*G$, UV-A and red lights) increased under the exclusive LED light. The total phenolic compounds increased by cultivation under all the LED lights, except the UV-A and mixed lights ($R^*G$ and $B^*R^*G^*U$). The DPPH radical scavenging activity was also improved by all the LED lights, except the mixed light ($R^*G$).

• Journal of Dairy Science and Biotechnology
• /
• v.26 no.2
• /
• pp.1-8
• /
• 2008

Human milk contains the nutrients for the growth and the development of the newborn. It contains specific proteins, lipids, and other components designed to be easily digestible and which play important roles in infant nutrition. However, when the lactation is failure or milk secretion is not enough, bovine milk based dried formulations, which is called infant formula, have been widely used for infant feeding. In this study, we investigated protein composition and amino acids profile related to easy digestion; fatty acids composition and LCPUFA(DHA and ARA) related to brain and eye development; synbiotics which take advantage of both probiotics and prebiotics; and colostrum-originated functional micronutrient as major issues in the recent infant formula. Domestic infant formulas, which are based on the research of human and bovine milk rich in functional components for immunity, growth, anti-allergenicity, digestion and brain development, have been developed to be similar to human milk.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.28 no.2
• /
• pp.333-341
• /
• 1999

This study was conducted to investigate physicochemical and functional properties of turnip. The concentrations of antocyanin in the rind of root was 3.24mg%, which was about 3.5 times higher than those in the flesh. Among free amino acids in each part of turnip, glutamic acid showed the highest concentrations(132.5mg%) in the root followed by alanine(25.0mg%), valine (23.3mg%), and serine (20.7mg%). Contents of minerals in the root of turnip were 395.7mg% for potassium, 187mg% for calcium, 53.6mg% for phosphate, and 40.7mg% for magnesium. According to dynamic heasdspace analysis, dimethyl disulfide was the most abundant flavor components from the juice of fresh turnip and other volatile components such as dimethyl trisulfide, 1 hexanal, 2 methyl 1 butamine, and 1 penten 3 ol were also identified. From the blanched turnip, however, 3 isothiocyanato 1 propene and 4 isothiocyanato 1 butene were mainly detected. Fresh and blanched turnips were extracted with water or 70% acetone to investigate percent yield. The concentrations of total polyphenols in the extracts of fresh turnip were higher than those of blanched turnip. The nitrite scavenging effects of water and 70% acetone extracts from fresh or blanched turnip were decreased as pH was increased. Between two water extracts, the 30oC water extracts showed the higher values of electron donating ability than 95$^{\circ}C$ water extracts.

• The Korean Journal of Physiology and Pharmacology
• /
• v.1 no.2
• /
• pp.185-193
• /
• 1997

The characteristics of $Na^+$-dependent cycloleucine uptake was investigated in OK cells with regard to substrate specificity and regulation by protein kinase C (PKC). Inhibition studies with different synthetic and natural amino acids showed a broad spectrum affinity to neutral amino acids regardless of their different side chains including branched or aromatic, indicating that the $Na^+$-dependent cycloleucine uptake in OK cells is mediated by System $B^o$ or System $B^o$-like transporter rather than the classical System A or ASC. Phorbol 12-myristate 13-acetate (PMA) and phorbol 12,13-dibutyrate, but not $4{\alpha}-PMA$ elicited a time-dependent biphasic stimulation of $Na^+$-dependent cycloleucine uptake, which produced early transient peak at 30 min and late sustained peak at 180min. Both the early and late stimulations by PMA were due to an increase in Vmax and not due to a change in Km. PKC inhibitors blocked both the early and late stimulation by PMA, while protein synthesis inhibitors blocked the late stimulation only. These results suggest the existence and regulation by PKC of System $B^o$ or System $B^o$-like broad spectrum transport system for neutral amino acids in OK cells.

• The Korean Journal of Community Living Science
• /
• v.28 no.2
• /
• pp.203-215
• /
• 2017

This study was carried out to compare the major nutrient components and antioxidant activities of Stachys sieboldii Miq leaf and root powders. For proximate compositions, crude protein and crude fat contents of leaf powder were higher than those of root powder, whereas contents of crude ash and carbohydrates were lower in leaf powder. The content of glutamic acid was greater in amino acids of leaf and root powders, and contents of total amino acids and essential amino acids were higher in leaf powder compared with root powder. Root powder contained a higher level of total unsaturated fatty acids than leaf powder. Total contents of organic acids were higher in leaf powder; tartaric acid was the major organic acid in leaf powder, and malic acid was the major organic acid in root powder. The content of vitamin A was higher in leaf powder than in root powder. However, vitamin E content was higher in root powder than in leaf powder. Total mineral contents of leaf powder were higher than those of root powder, and mineral contents of leaf and root powders were in the order of K>Ca>Mg. Extract yields of leaf and root powders were 27.21% and 58.51%, respectively. Total polyphenols and total flavonoids of leaf extract were 236.35 mg/g and 1.90 mg/g, respectively, which were higher than those of root extract. The $IC_{50}$ values of leaf and root ethanol extracts based on DPPH hydroxyl scavenging were 0.69 mg/mL and 5934.31 mg/mL, respectively, and antioxidative activities of ethanol extracts from all Stachys sieboldii Miq parts dose-dependently increased. These results suggest that Stachys sieboldii Miq can be recommended as an edible functional food material.

• KSBB Journal
• /
• v.13 no.5
• /
• pp.593-598
• /
• 1998

Biological deinking process of used papers was studied by the polymer modified cellulase. Cellulase was modified with copolymers which consist of polyoxyethylene derivative and maleic anhydride(MA). The MA functional groups of copolymer can react with amino acids groups of the cellulase without much loss of activity. Modified degree of amino acids was controlled by the added copolymer. The maximum modified degree was about 60% and it was obtained when the weight ratio of copolymer and cellulase was 4. The remained activity of the maximum modified cellulase(MMC) was higher than 80% of native cellulase. The MMC's concentration was 0.05-2.0 wt% relative to the dry paper. In mechanical pulping process, cellulase enhanced the detachment of the ink particle from the used paper by partial hydrolysis of the fiber. The polyoxyethylene of modified cellulase produced the forms which can float the separated ink particle. Compared to the convention deinking method with NaOH or organic chemicals, the new biological deinnking process improved the physical properties such as freeness, tearing strength and whiteness.

• Korean Journal of Food Science and Technology
• /
• v.50 no.6
• /
• pp.680-687
• /
• 2018

This study compared the nutritional value of quinoa cultivated in different regions, i.e., Peru (PQ), United States (UQ), and Korea (KQ), focusing on their proximate and nutrient compositions and functional components. Moisture, protein, lipid, and ash contents were highest in KQ, and the carbohydrate content was the highest in UQ. KQ had the highest amount of total amino acids, especially lysine. KQ had the lowest levels of Na but the highest levels of K, P, Fe, Mg, Zn, and Mn. The antioxidant compounds, quercetin and kaempferol were not detected in KQ, which consequently had the lowest total phenolic and total flavonoid contents (TPC and TFC, respectively). These values were comparatively higher in UQ. Meanwhile, PQ had the highest TPC and TFC values as well as kaempferol content, but lacking quercetin. These results demonstrate that the nutritional value of quinoa varies according to the region in which it is cultivated.

• Journal of Dairy Science and Biotechnology
• /
• v.41 no.1
• /
• pp.34-43
• /
• 2023

Hydrolysis of whey-derived proteins using lactic acid bacteria (LAB) utilizes the mass culture method and fermentation of LAB to produce effective bioactive peptides. Whey protein has the biological potential of its precursors, but the active fragments may not be released depending on the hydrolysis method. As an alternative to these problems, the nutritional and bioactive functionality of the hydrolysis method have been reported to be improved using LAB for whey protein. Peptide fractions were obtained using a sample fast protein liquid chromatography device. Antioxidant activity was verified for each of the five fractions obtained. In vitro cell experiments showed no cytotoxicity and inhibited nitric oxide production. Cytokine (IL [interleukin]-1α, IL-6, tumor necrosis factor-α) production was significantly lower than that of lipopolysaccharides (+). As a result of checking the amino acid content ratio of the fractions selected through the AccQ-Tag system, 17 types of amino acids were identified, and the content of isoleucine, an essential amino acid, was the highest. These properties show their applicability for the production of functional products utilizing dietary supplements and milk. It can be presented as an efficient method in terms of product functionality in the production of uniform-quality whey-derived peptides.

• Journal of Life Science
• /
• v.17 no.1 s.81
• /
• pp.125-131
• /
• 2007

Amino acid and fatty acid compositions of the physiological activity substance in the seed and pulpy substance of feral peach (Prunus persica Batsch var. davidiana Max.) were analyzed for the use as an biohealth functional processed products. The proximate compositions in the vacuum freeze dried seed and pulpy substance of feral peach were carbohydrate 63.92% and 75.11%, crude protein 27.85% and 12.77%, moisture 3.61% and 4.69%, crude fat 1.21% and 4.80%, crude ash 3.41% and 2.63%, respectively. Total amino acid contents in the protein of feral peach seed were 3,444.35 mg%, and the major amino acids were aspartic acid(681.10 mg%), glutamic acid(495.48 mg%), alanine(283.66 mg%), serine(251.36 mg%), proline(229.80 mg%), lysine(192.31 mg%) and leucine(191.34 mg%), respectively. Total amino acid contents in the protein of feral peach pulpy substance were 1,064.02 mg%, and the major amino acids followed aspartic acid(250.15 mg%), glutamic acid(129. 63 mg%), lysine, proline, leucine, alanine and serine, in a decreasing order. The richest total amino acid content contained in feral peach seed and pulpy substance was aspartic acid, followed by glutamic acid. The amount of free amino acids of feral peach seed were 6,215.34 ms%, and the major free amino acids were glutamic acid(827.25 mg%), threonine, valine and $\beta-aminobutyric$ acid, respectively. Free amino acid contents of pulpy substance were 683.82 mg%, and the major free amino acids were glutamic acid(339.49 mg%), serine proline, alanine and $\gamma-amino-n-butyric$ acid. Especially, in the case of glutamic acid, it was highest. The compositions of major total fatty acid in the lipid feral peach (Prunus persica Batsch var. davidiana Max.) seed and pulpy sabstance were linoleic acid($C_{18:2}$, n-6) and linolenic acid($C_{18:3}$, n-3), particularly.