• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.42 no.4
• /
• pp.433-440
• /
• 2016

In this study, a poly (amino acid)s derivative grafted with retinoic acids, which could form self-assemblies in an aqueous solution, was successfully synthesized. The synthesized amphiphilic poly (amino acid)s were controlled with 5, 10, 30 mol% substitution of retinoic acid. Then, the amphiphilic poly (amino acid)s were self-assembled by inter/intra molecular stacking of retinoic acids in an aqueous solution. Also, the increasing the degree of substitution (DS) of retinoic acids decreased the size of self-assembled nanoparticles and induced structural transition to bilayer structure from spherical structure. The retinol was stably encapsulated into a core of self-assembled nanoparticle with 10 mol% of DS. This strategy to prepare the self-assemblies of amphiphilic polyaspartamide will serve to improve the efficiency of targeted delivery for a functional cosmetic with various biological modalities.

• Fisheries and Aquatic Sciences
• /
• v.18 no.1
• /
• pp.13-20
• /
• 2015

Calculated chemical scores (computed in relation to the FAO/WHO reference protein) for salmon liver protein hydrolysates indicated that all amino acids (other than methionine and threonine) were present in adequate or excess quantities; thus, the raw liver material is a good source of essential amino acids. The hydrophobic amino acids contents in hydrolysates prepared from Oncorhynchus keta and O. gorbuscha were 38.4 and 39.1%, respectively. The proportion of released peptides exceeding 500 kDa was reduced when hydrolysates were treated with the commercial enzyme Alcalase, although proportions in the following MW ranges were elevated: 100-500 kDa and <50 kDa. The optimal conditions for enzymatic hydrolysis were as follows: pH 7.0, $50^{\circ}C$, and a reaction time of 1 h. Of the different proteases tested, Alcalase was the most efficient for production of salmon liver hydrolysate with the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity. The hydrolysates prepared from salmon liver had a balanced amino acid composition. The liver protein hydrolysates contained low molecular weight peptides, some of which may be bio-active; this bio-active potential should be investigated. Inhibition of the DPPH radical increased with increased degree of hydrolysis (DH), regardless of protease type. DPPH radical scavenging abilities, antithrombotic effects and ${\alpha}$-glucosidase enzyme inhibition effects of O. keta liver hydrolysate increased in a dose-dependent manner. Thus, salmon liver hydrolysate may be useful in functional food applications and as a source of novel products.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.24 no.5
• /
• pp.816-828
• /
• 1995

During the industrial preparation and the storage of foods, the side chain of some protein-bound amino acids can react chemically each other or with other molecules present in the food. The following reactions have been described : destruction of amino acids, racemization, protein-protein interactions, reactions of proteins with reducing sugars, oxidizing agents, or polyphenols. Apart from total destruction, the main reacitons are the forming of Maillard reactions products(e.g. fructoselysine) and the crosslinking with other amino acids in the same or in another protein molecule(e.g. lysinoalanine). The most often involved amino acid is lysine because of its free functional ${\varepsilon}-amino$ acid group. Generally derivatives of amino acids or crosslinks in polypeptides influence the bioavailability and the overall digestibility of the protein. This work reviews the technological, analytical, nutritional, and physiological problems related to the formation of fructoselysine and lysinolalnine in human foods, and evaluates the possible health risk for humans. A summary of the available information is of help in considering whether or not the presence of fructoselysine/lysinoalanine in foods represents a danger to man. The reduction in protein quality through these reactions is not a problem for the general population, but it is extremely important in infant foods, since infants are often nourished with a limited number of food product(e.g. formular foods) which are sensitive to the Mailard reaction.

• Culinary science and hospitality research
• /
• v.20 no.3
• /
• pp.37-49
• /
• 2014

In order to elucidate the usefulness of Lycopene, a cherry tomato variety, as a food material, the compositions of free amino acids, amino acid metabolites and polyphenol compounds were analyzed using HPLC and LC-MS/MS method. Lycopene contained eighteen free amino acids except for L-Cys and L-Try. L-Glu was the most abundant free amino acid, followed by L-Gln and L-Asp. The percentages of L-Glu, L-Gln and L-Asp of total free amino acid were 55.5%, 15.9% and 9.9% respectively. Lycopene contained essential amino acids with the exception of tryptophan. The following amino acid metabolites were found : ${\gamma}$-aminobutyric acid(GABA), carnitine(L-Car), o-phosphoethanolamine(o-Pea), hydroxylysine(Hyl) phosphoserine (p-Ser), N-methyl-histidine(Me-His), ethanolamine($EtNH_2$). Especially, GABA known as a neurotransmitter was present at a high level(305.99 mg/100 g dry weight). We identified the following polyphenol compounds in the cherry tomatoes : caffeic acid-hexose isomer I (CH I), caffeic acid-hexose isomer II (CH II), 3-caffeoylquinic acid(3-CQA), 5-caffeoylquinic acid(5-CQA), caffeoylquinic acid isomer(CQAI), quercetin-hexose-deoxyhexose-pentose(QTS), quercetin-3-rutinoside(Q-3-R), di-caffeoylquinic acid(di-CQA), tri-caffeoylquinic acid(tri-CQA), naringenin chalcone(NGC). Large quantities of Q-3-R and NGC known as bioactive compounds were found. These results revealed that Lycopene variety contained various nutritional and bioactive compounds and would be a potent functional food material.

• Journal of Microbiology
• /
• v.44 no.1
• /
• pp.50-53
• /
• 2006

Cys-29 and Cys-251 of Streptomyces albus valine dehydrogenase(ValDH) were highly conserved in the corresponding region of $NAD(P)^+$-dependent amino acid dehydroganase sequences. To ascertain the functional role of these cysteine residues in S. albus ValDH, site-directed mutagenesis was performed to change each of the two residues to serine. Kinetic analyses of the enzymes mutated at Cys-29 and Cys-251 revealed that these residues are involved in catalysis. We also constructed mutant ValDH by substituting valine for leucine at 305 by site-directed mutagenesis. This residue was chosen, because it has been proposed to be important for substrate discrimination by phenylalanine dehydrogenase (PheDH) and leucine dehydrogenase (LeuDH). Kinetic analysis of the V305L mutant enzyme revealed that it is involved in the substrate binding site. However it displayed less activity than the wild type enzyme toward all aliphatic and aromatic amino acids tested.

• Journal of Microbiology and Biotechnology
• /
• v.18 no.6
• /
• pp.1050-1058
• /
• 2008

A gene encoding a dextransucrase (dsrBCB4) that synthesizes only ${\alpha}$-1,6-linked dextran was cloned from Leuconostoc mesenteroides B-1299CB4. The coding region consisted of an open reading frame (ORF) of 4,395 bp that coded a 1,465-amino-acids protein with a molecular mass of 163,581 Da. The expressed recombinant DSRBCB4 (rDSRBCB4) synthesized oligosaccharides in the presence of maltose or isomaltose as an acceptor, plus the products included ${\alpha}$-1,6-linked glucosyl residues in addition to the maltosyl or isomaltosyl residue. Alignments of the amino acid sequence of DSRBCB4 with glucansucrases from Streptococcus and Leuconostoc identified conserved amino acid residues in the catalytic core that are critical for enzyme activity. The mutants D530N, E568Q, and D641N displayed a 98- to 10,000-fold reduction of total enzyme activity.

• Fisheries and Aquatic Sciences
• /
• v.22 no.5
• /
• pp.10.1-10.14
• /
• 2019

Fish skin waste accounts for part of the solid waste generated from seafood processing. Utilization of fish skin by bioconversion into high-grade products would potentially reduce pollution and economic cost associated with treating fish processing waste. Fish skin is an abundant supply of gelatin and collagen which can be hydrolyzed to produce bioactive peptides of 2-20 amino acid sequences. Bioactivity of peptides purified from fish skin includes a range of activities such as antihypertensive, anti-oxidative, antimicrobial, neuroprotection, antihyperglycemic, and anti-aging. Fish skin acts as a physical barrier and chemical barrier through antimicrobial peptide innate immune action and other functional peptides. Small peptides have been demonstrated to possess biological activities which are based on their amino acid composition and sequence. Fish skin-derived peptides contain a high content of hydrophobic amino acids which contribute to the antioxidant and angiotensin-converting enzyme inhibitory activity. The peptide-specific composition and sequence discussed in this review can be potentially utilized in the development of pharmaceutical and nutraceutical products.

• Molecules and Cells
• /
• v.42 no.5
• /
• pp.386-396
• /
• 2019

Labeling of a protein with a specific dye or tag at defined positions is a critical step in tracing the subtle behavior of the protein and assessing its cellular function. Over the last decade, many strategies have been developed to achieve selective labeling of proteins in living cells. In particular, the site-specific unnatural amino acid (UAA) incorporation technique has gained increasing attention since it enables attachment of various organic probes to a specific position of a protein in a more precise way. In this review, we describe how the UAA incorporation technique has expanded our ability to achieve site-specific labeling and visualization of target proteins for functional analyses in live cells.

• Horticultural Science & Technology
• /
• v.30 no.4
• /
• pp.409-416
• /
• 2012

The amount of cellular components including soluble sugars, amino acids, organic acids and glucosinolates (GLS) was investigated during radish root processing to develop a radish beverage. The radish root was divided into two parts, white and green tissue, and processed separately by extracting the juice from the fresh tissue and from the boiled tissue to compare differences in the components content among the preparations. The overall palatability of both the fresh and boiled extracts from the green part of the radish was higher than that of the same extracts from the white part. The sweetness of extract by boiling increased and its pungency decreased, thereby the palatability increased by being compared to the fresh radish extract. The sweetness was affected by sucrose not by glucose or fructose of monosaccharides by showing different sucrose contents according to treatment comparing palatability. Malic acid was identified as primary organic acid, and the content was higher in both the fresh and boiled extracts from the white part than in the extracts from the green part of the radish. The fresh extract from the green part of the radish contained more essential amino acids, such as threonine and valine, and more hydrophilic amino acids including glutamic acid, aspartic acid, and arginine than those of the fresh extract from the white part, suggesting the green fresh part is more palatable than the white fresh part. The main sulfur compound was ethylthiocyanate in radish, and others were butyl isothiocyanate, dimethyl-disulfide, and 4-methylthio-3-butylisothiocyanate. The four GLS were detected much more in the fresh green and fresh white parts of the radish because they evaporated during boiling. The contents of the four sulfur compounds were higher in the white fresh part than in the green fresh part, which is likely the reason the pungency was higher and the palatability was lower in the white fresh part than in the green fresh part of the radish. The ascorbic acid content was higher in the fresh extract compared to the boiled extracts from both the green and white parts. Taken together, these findings indicate that fresh radish extract is superior to obtain in terms of retaining desirable nutritional and functional components for health.

• Food Science and Preservation
• /
• v.13 no.3
• /
• pp.375-381
• /
• 2006

This study was carried out to analyze the nutritional component of Lepista nuda in order to estimate its nutritional and functional values. The content of moisture were $90.90{\pm}0.09%$ carbohydrate $4.34{\pm}0.07%$, crude protein $3.70{\pm}0.03%$, ash $0.55{\pm}0.04%$, and crude fat $0.47{\pm}0.01%$, respectively The reducing sugar was $636.17{\pm}7.50mg$. Total amount of free sugar was 97.32 mg, which were mainly composed of galactose (51.98 mg) and trehalose (22.48 mg). In the results of mined analysis, the content of K was the highest as $103.10{\pm}0.18mg$, followed by $56.01{\pm}0.20mg$ of Mg. The total content of hydrolyzed amino acid was 310.39 mg which consist of essential amino acids including valine (25.40 mg), leucine (22.52 mg), lysine (21.34 mg) and 198.89 mg of non-essential amino acids including glutamic acid (60.72 mg), aspartic acid (30.17 mg), and alanine (29.72 mg), as the major amino acids. free amino acids were 220.86 mg which were composed of essential amino acids (36.21 mg) inclusive of isoleucine (21.57 mg) and threonine (11.20 mg) and non-essential amino acids (184.65 mg) including glutamic acid (42.78 mg) and aspartic acid (32.44 mg) as major amino acids. Total content of amino acid derivatives was 187.85 me and that of hydroxyproline was highest as 121.50 mg.