• BMB Reports
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• v.33 no.1
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• pp.82-88
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• 2000

A homologous gene to alanine racemase was cloned from a hyperthermophilic bacterium, Aquifex pyrophilus. The cloned gene encodes a protein of 341 amino acids, which has a significant homology to alanine racemase of Bacillus stearothermophilus, Lactobacillus brevis, and E. coli. When the gene was expressed in Escherichia coli, it produced a 40 kDa protein. The purified protein contains one mole pyridoxal 5-phosphate per one mole of protein, which is essential for catalytic activity of alanine racemase. The purified protein catalyzed racemization of L-alanine to D-alanine, or vice versa, indicating that the cloned gene encoded alanine racemase. It also showed significant racemization activity against L-serine and ${\alpha}-aminobutylic$ acid. The A. pyrophilus alanine racemase showed strong thermostability, and it maintained catalytic activity in the presence of organic solvents.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.2
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• pp.296-304
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• 2009

The nutritional significance of essential amino acids, as well as non-essential amino acids, is well documented in poultry production with regards to growth performance and protein accretion. However, the function of amino acids in the stress response is still unclear. L-Pipecolic acid, a L-lysine metabolite in the brain, induced a hypnotic and sedative effect acting via the ${\gamma}$- aminobutyric acid receptors. L-Arginine also induced a sedative effect via its metabolism to L-ornithine. In addition, three-carbon nonessential amino acids like L-alanine, L-serine and L-cysteine also induced sedative effects. These facts suggest that the requirement for amino acids in both essential and non-essential types may require reconsideration to add the concept of stress amelioration in the future.

• The Korean Journal of Food And Nutrition
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• v.5 no.1
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• pp.49-54
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• 1992

In an attempt of develop composite flours, D. aimadoimo of yams in Korea was investigated with respect to its physicochemical properties and sensory analysis with baking bread. The results are summarized as follows ; 1. Yam had 73.21% of water, 21.65% of carbohydrate, 3.3% of crude protein, 0.25% of fat, 1.60% ash and 20.3%of starch. 2. Sucrose was 78% of the total free sugars in yam flour. It was contained which 67% of total free amino acids were serine, arginine & alanine and 23.6% of total amino acids was glutamic acid. 3. As the yam flour level in amylogram patterns (8% dry basis) was increased, the initial pasting temperature was increased and the viscosity decreased. 4. Replacement of yam flour with 10% wheat flour was the bests in sensory evaluation of the products.

• Applied Microscopy
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• v.23 no.2
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• pp.84-96
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• 1993

This study was to investigate the effects of maternal diabetes on the lung tissue of the fetal rat using lectin histochemistry and electron microscope technique. Maternal diabetes was induced by intraperitoneal injection of streptozotocin (75 mg/kg the body weight) into pregnant Sprague-Dawley rats on the 7th day of gestation. Fetuses of streptozotocin induced diabetic rats exhibited delayed lung maturation and reduced air space. In lectin histochemistry, the binding of Maclura pomifera (MPA) to fetal lungs from diabetic mothers was reduced, but no significant changes in the bindings of Concanavalin A (Con A), Wheat germ agglutinin (WGA), Ricinus communis I (RCA I) and Griffonia simplicifolia (GSI-$B_4$) were noted. Because the MPA has affinity to terminal N-acetyl-D-galactosamine residues constantly linked O-glycosidically to serine or threonine, the present findings may indicates that maternal diabetes interfere with the processes of O-linked glycosylation in fetal rat lung.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.314.1-314.1
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• 2002

Bacterial ${\beta}$-lactamases provide resistance to ${\beta}$-lactams by hydrolyzing the ${\beta}$-lactam bond, On the basis of their catalytic mechanisms. ${\beta}$-lactamases are divided into two major groups. Class A. C and D which belong to the first group require serine in the active site and class B which is the second group require Zn(II) for their activity. Among class B enzymes, Bacteroides fragilis ${\beta}$-lactamase (CcrA enzyme) require two Zn(II) ions per monomer for maximal enzymatic activities. (omitted)

• Journal of Microbiology and Biotechnology
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• v.31 no.3
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• pp.447-455
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• 2021

Strains of four Bacillus spp. were respectively inoculated into sterilized soybeans and the free amino acid profiles of the resulting cultures were analyzed to discern their metabolic traits. After 30 days of culture, B. licheniformis showed the highest production of serine, threonine, and glutamic acid; B. subtilis exhibited the highest production of alanine, asparagine, glycine, leucine, proline, tryptophan, and lysine. B. velezensis increased the γ-aminobutyric acid (GABA) concentration to >200% of that in the control samples. B. sonorensis produced a somewhat similar amino acid profile with B. licheniformis. Comparative genomic analysis of the four Bacillus strains and the genetic profiles of the produced free amino acids revealed that genes involved in glutamate and arginine metabolism were not common to the four strains. The genes gadA/B (encoding a glutamate decarboxylase), rocE (amino acid permease), and puuD (γ-glutamyl-γ-aminobutyrate hydrolase) determined GABA production, and their presence was species-specific. Taken together, B. licheniformis and B. velezensis were respectively shown to have high potential to increase concentrations of glutamic acid and GABA, while B. subtilis has the ability to increase essential amino acid concentrations in fermented soybean foods.

• Biomolecules & Therapeutics
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• v.31 no.2
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• pp.141-147
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• 2023

Antibiotic resistance has emerged as a global threat to modern healthcare systems and has nullified many commonly used antibiotics. β-Lactam antibiotics are among the most successful and occupy approximately two-thirds of the prescription antibiotic market. They inhibit the synthesis of the peptidoglycan layer in the bacterial cell wall by mimicking the D-Ala-D-Ala in the pentapeptide crosslinking neighboring glycan chains. To date, various β-lactam antibiotics have been developed to increase the spectrum of activity and evade drug resistance. This review emphasizes the three-dimensional structural characteristics of β-lactam antibiotics regarding the overall scaffold, working mechanism, chemical diversity, and hydrolysis mechanism by β-lactamases. The structural insight into various β-lactams will provide an in-depth understanding of the antibacterial efficacy and susceptibility to drug resistance in multidrug-resistant bacteria and help to develop better β-lactam antibiotics and inhibitors.

• Biomedical Science Letters
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• v.2 no.1
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• pp.21-30
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• 1996

MAP kinases are a family of serine/threonine specific protein kinases becoming activated in response to different proliferative stimuli by phosphorylation at both threonine and tyrosine residue. Present study shows that MAP kinase was purified from P388 murine leukema cells by SP sephadex C-50, phenyl superose and Mono Q column chromatography and identified with anti-ERKl antibody by western blotting. Immnublotting analysis to the crude extract of P388 cell lysate shows 44 kD and other minor bands but partial purified fraction eluted from phenyl supherose column have 44kD and 66 kD isoform. Subcloned GST-fusion protein from N-terminal of $p56^{kk}$ was tested as a substrate for MAP kinase phosphorylation. It was showed that the wild type and mutant forms(S42A) were fully phosporylated by purified MAP kinase fraction as com-pare with the other mutant form(S59A). This finding suggest that those GST-fusion proteins may be used as substrate for the in vitro test of MAP kinase.

• Microbiology and Biotechnology Letters
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• v.5 no.1
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• pp.36-45
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• 1977

A piscicidal substance was isolated from the culture medium of Streptomyces umbrosus by avicel column chromatography and avicel thin layer chromatography after extration with chroloform. Bluegreen fluorescence was emitted under UV irradiation. Factors which govern toxin production and nutrition requirement for high toxin titres were observed. Nutritional uptake for toxin production was not curresponded with that for cell growth. Alanine, valine, serine asparagine, arginine, histidine, urea and sodium nitrate as a carbon source and glucose, mannose, rhamnose, xylose, arabitol and starch as a carbon source were recognized as a favorable nutrient for high toxin production. Magnesium was essential factor whereas vitamins were not of effective. Most of toxin was formed simultaneously with cell growth in esponential phase. Maximal production was observed for six day culture at 3$0^{\circ}C$. Tissues of gill, kidney and pnacreas in Cyprinus carpio were denatured extreamly after treating with the substance. Atrophied nucleous, indented membrane and degradated cytoplasm with necrotic affectness were noted on each tissue. The chemical formula of the substance was designated as $C_{38}$ $H_{66}$ $NO_4$.

• Journal of Microbiology and Biotechnology
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• v.29 no.2
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• pp.321-329
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• 2019

Hair loss, also known as alopecia, is a common dermatological condition of psychosocial significance; development of therapeutic candidates for the treatment of this condition is, hence, important. Silibinin, a secondary metabolite from Silybum marianum, is an effective antioxidant that also prevents various cutaneous problems. In this study, we have investigated the effect of silibinin on hair induction using three-dimensional (3D) cultured, human dermal papilla (DP) spheroids. Silibinin was found to significantly increase viability through AKT serine/threonine kinase (AKT) activation in 3D DP spheroids. This was correlated with an increase in the diameter of the 3D DP spheroids. The activation of the wingless and INT-1 (Wnt)/${\beta}$-catenin signaling pathway, which is associated with hair growth induction in the DP, was evaluated using the T cell-specific transcription factor and lymphoid enhancer-binding factor (TCF/LEF) transcription factor reporter assay; results indicated significantly increased luciferase activity. In addition, we were able to demonstrate increased expression of the target genes, WNT5a and LEF1, using quantitative real-time PCR assay. Lastly, significantly elevated expression of signature genes associated with hair induction was demonstrated in the 3D DP spheroids treated with silibinin. These results suggest that silibinin promotes proliferation and hair induction through the AKT and Wnt/${\beta}$-catenin signaling pathways in 3D DP spheroids. Silibinin can be a potential candidate to promote hair proliferation.