• Applied Biological Chemistry
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• v.12
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• pp.43-51
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• 1969

The purpose of this study was to determine protein amino acid contents of some Korean foods by gas-liquid chromatography, and to evaluate this technique as a procedure for the quantitative determination of amino acids in foods. The crude protein content of foods was also estimated from the nitrogen content. 1. Nitrogen content of each food sample was determined previously to adjust the amount of sample for GLC analysis 2. In the analysis of 17 known amino acids, a linear relationship was found between the weight of 13 amino acids of 17 amino acids, the internal standard as well as the injection volume of a mixture and the detector responses for the derivatives of the amino acids. No response for arginine, cystein, histidine, and tyrosine was observed. 3. The relative molar response (RMR) values for the 13 amino acids of standard solution relative to glutamic acid as '1.00' were obtained under normal operating conditions with a hydrogen flame ionization detector. 4. The recovery of amino acids from their mixtures with natural food materials was carried out. The recoveries were essentially quantitative except threonine and serine. An overall mean recovery of 11 amino acids was $101.4{\pm}8.4$ per cent before hydrolysis and $98.1{\pm}8.7$ per cent after hydrolysis of samples. 5. The comparative analysis of the acid hydrolysates of two food samples by gas-liquid and ion-exchange chromatographic analysis were carried out. In white-bait pemmican, only threonine and asparagine amounts by GLC analysis had similar values to those obtained by ion-exchange chromatography. The other seven amino acids gave higher values as measured by GLC than by ion-exchange. With the food sample, soybean, alanine, valine, asparagine, and glutamic acid were in good agreement in two analysis, while leucine, proline, threonine, phenylalanine, and lysine were found in slightly higher concentrations in the GLC analysis. 6. Grant variations of amino acid content were found among samples analyzed. The amino acid contents of each sample were compared with the values found in the literature.

• Korean Journal of Microbiology
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• v.29 no.4
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• pp.209-214
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• 1991

The PRD1 DNA polymerase is a small multi-functional enzyme containing conserved amino acid sequences shared by family B DNA polymerases. Thus the PRD1 DNA polymerase provides an useful model system with which to study structure-functional relationships of DNA polymerase molecules. In order to investigate the functional and structural roles of the highly conserved amino acid sequences, we have introduced three mutations into a conserved amino acid of the PRD1 DNA polymerase. Genetic complememtation study indicated that each mutation inactivated DNA polymerase catalytic activity.

• Journal of Sericultural and Entomological Science
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• v.4
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• pp.85-95
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• 1965

This report is to observe the amino acid composition at silk fibroins among varieties by using paper chromatography method and to study how they may concern with the genetical problem and the biochemical synthesis of the fibroin in silkgland. The results reached are as follows: 1. The amino acid composition of silk fibroin among varieties were observed as similar with each other on the paper chromatogram pictures. 2. In spite of the results of the amino acid composition analysis was similar with other workers results, there was some difference among varieties in numerical analysis. 3. The amino acid composition was considered to concern somewhat with the genetic problem of silkworm. 4. Some nutritive amino acids are considered to related with the worm growth more than the silk fibroin. 5. The paper chromatography of this report showed an unknown amino acid which was not found before in specific species silk fibroin and it is imagined as Hydroxyproline in view of other worker's graphy result. 6. The biochemical synthesis mechanism of silk fibroin in the silk gland, neither Stepwise process nor Template, could stand with the results of this paper satisfactory one side.

• Journal of Marine Bioscience and Biotechnology
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• v.10 no.1
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• pp.18-25
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• 2018

Chlorella is quantitatively and qualitatively high in protein with balanced essential amino acid profiles, vitamins and minerals. ${\gamma}-Aminobutyric$ acid (GABA) is broadly distributed in nature and fulfills multi-physiological functions including effect such as a health-promoting functional compound. To improve the GABA production, Chlorella protothecoides were grown through the modified mixtrophic culture medium containing 2L of sterilized bristol medium with 0.01% urea and 4.0% glucose in a 5L fermenter. The results showed that nineteen kinds of amino acid including GABA at C. protothecoides sample were analyzed using high performance liquid chromatography (HPLC). Glutamic acid in total concentration (%) of amino acid is the most abundant amino acid (33.10%), followed by alanine (20.48%) and GABA (17.48%). Three amino acids including GABA were responsible for more than 70% total concentration in C. protothecoides sample including eight essential and nine non-essential amino acids: aspartic acid, asparagine, serine, glutamine, histidine, glycine, threonine, arginine, tyrosine, valine, methionine, tryptophan, phenylalanine, isoleucine, leucine, lysine. As a result of this experiment, it is expected that Chlorella will be developed to a critical product having high value as, GABA, functional food materials.

• Journal of the Korean Chemical Society
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• v.54 no.5
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• pp.506-514
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• 2010

A new series of ligands N-[(benzoylamino)-thioxomethyl]-amino acid (HL) were synthesized by reaction of benzoylisothiocyanate with various amino acids namely aspartic acid [BATA] (1), glutamic acid [BATG] (2), methionine [BATM] (3), leucine [BATL] (4), and tryptophan [BATT] (5). The ligands were characterized by elemental analysis, IR and NMR spectra. Some transition metal complexes ($ML_2$) for these ligands (6-8) were prepared; [M=Cu(II), Co(II), or Ni(II)], and characterized by elemental analysis, IR and $^1H$ NMR spectra. Antibacterial study showed that all the ligands have no antibacterial activity, whereas ($ML_2$) complexes; [M = Cu(II), Co(II), or Ni(II)] have antibacterial activity towards (Gram -ive) Escherichia (NCTC5933) and (Gram +ive) Staphylococcus (NCTC6571) and have no toxicity on (BALB/C) Albino mice.

• Journal of the Korean Data and Information Science Society
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• v.16 no.4
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• pp.745-758
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• 2005

This paper presents a statistical analysis on the position-specific distributions of amino acid residues in transmembrane proteins. A hidden Markov model segments membrane proteins to produce segmented regions of homogeneous statistical property from variable-length amino acids sequences. These segmented residues are analyzed by using chi-square statistic and relative-entropy in order to find position-specific amino acids. This analysis showed that isoleucine and valine concentrated on the center of membrane-spanning regions, tryptophan, tyrosine and positive residues were found frequently near both ends of membrane.

• Interdisciplinary Bio Central
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• v.6 no.4
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• pp.3.1-3.10
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• 2014

Amino acid substitution matrices are essential tools for protein sequence analysis, homology sequence search in protein databases and multiple sequence alignment. The PAM matrix was the first widely used amino acid substitution matrix. The BLOSUM series then succeeded the PAM matrix. Most substitution matrixes were developed by using the statistical frequency of substitution between each amino acid at blocks representing groups of protein families or related proteins. However, substitution of amino acids is based on the similarity of physiochemical properties of each amino acid. In this study, a new approach was used to obtain major physiochemical properties in multiple sequence alignment. Frequency of amino acid substitution in multiple sequence alignment database and selected attributes of amino acids in physiochemical properties database were merged. This merged data showed the major physiochemical properties through principle components analysis. Using factor analysis, these four principle components were interpreted as flexibility of electronic movement, polarity, negative charge and structural flexibility. Applying these four components, BAPS was constructed and validated for accuracy. When comparing receiver operated characteristic ($ROC_{50}$) values, BAPS scored slightly lower than BLOSUM and PAM. However, when evaluating for accuracy by comparing results from multiple sequence alignment with the structural alignment results of two test data sets with known three-dimensional structure in the homologous structure alignment database, the result of the test for BAPS was comparatively equivalent or better than results for prior matrices including PAM, Gonnet, Identity and Genetic code matrix.

• Journal of Plant Biotechnology
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• v.48 no.4
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• pp.228-235
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• 2021

The amino acids found in plants play important roles in protein biosynthesis, signaling processes, and stress responses, and as components in other biosynthesis pathways. Amino acid degradation helps maintain plant cells' energy states under certain carbon starvation conditions. Branched-chain amino acid transferases (BCATs) play an essential role in the metabolism of branched-chain amino acids (BCAAs) such as isoleucine, leucine and valine. In this paper, we performed genome-wide RNA-seq analysis using CsBCAT7-overexpressing Arabidopsis plants. We observed significant changes in genes related to flowering time and genes that are germination-responsive in transgenic plants. RNA-seq and RT-qPCR analyses revealed that the expression levels of some BCAA catabolic genes were upregulated in these same transgenic plants, and that this correlated with a delay in their senescence phenotype when the plants were placed in extended darkness conditions. These results suggest a connection between BCAT and the genes implicated in BCAA catabolism.

• Korean journal of food and cookery science
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• v.30 no.5
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• pp.564-572
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• 2014

This study was conducted to analyze the contents in the dietary fiber and amino acid compositions of 23 vegetables and 6 fruits and to identify the current contents. We generated data on the contents of total, insoluble and soluble dietary fiber (TDF, IDF and SDF), respectively. The TDF and IDF contents were lowest (0.56 g/100 g and 0.44 g/100 g) in wild garlic and highest (5.87 g/100 g and 5.66 g/100 g) in perilla leaves. A total of 18 kinds of amino acids were found in most samples. Essential and non-essential amino acid contents ranged from 53.16-2107.54 mg/100 g and 191.66-2892.28 mg/100 g, respectively. The highest essential and non-essential amino acid content was hot pepper leaves followed by perilla leaves and aralia. They had higher contents of both TDF and amino acids. The results of the study can serve as a fundamental source of information in DF and amino acids for diet planning.

• Journal of Life Science
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• v.34 no.3
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• pp.145-152
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• 2024

Seaweeds represent a widely harnessed marine resource that are valued for their abundant supply of essential nutrients, particularly proteins and amino acids. In Korea, where over 500 species of seaweed thrive and more than 50 are utilized for culinary purposes, seaweed has become a staple in regular diets. In this study, we focused on five of the most commonly consumed seaweed species in Korea: Capsosiphon fulvescens, Hizikia fusiforme, Porphyra yezoensis, Saccharina japonica, and Undaria pinnatifida. We closely examined the amino acid compositions of these five species. High-performance liquid chromatography showed that aspartic acid, glutamic acid, alanine, and leucine were the most abundant amino acids in the seaweeds. Principal component analysis revealed that the five seaweed species could be classified into three clusters according to their amino acid composition, partially corroborating findings from the phylogenetic analysis. Among various amino acids, glutamic acid, aspartic acid, and alanine were the primary amino acids driving differentiation. Notably, U. pinnatifida and C. fulvescens, which demonstrated close phylogenetic proximity, exhibited remarkably similar amino acid profiles. Conversely, although P. yezoensis and S. japonica shared a phylogenetic relationship, they displayed distinctly different amino acid compositions. H. fusiforme emerged as a distinct group in both analyses.