• Journal of Microbiology and Biotechnology
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• v.26 no.5
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• pp.959-966
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• 2016

Chlorophyll synthase (ChlG) and bacteriochlorophyll synthase (BchG) have a high degree of substrate specificity. The BchG mutant of Rhodobacter sphaeroides, BG1 strain, is photosynthetically incompetent. When BG1 harboring chlG of Synechocystis sp. PCC 6803 was cultured photoheterotrophically, colonies arose at a frequency of approximately 10^-8. All the suppressor mutants were determined to have the same mutational change, ChlG_I44F. The mutated enzyme ChlG_I44F showed BchG activity. Remarkably, BchG_F28I, which has the substitution of F at the corresponding 28^th residue to I, showed ChlG activity. The K_m values of ChlG_I44F and BchG_F28I for their original substrates, chlorophyllide (Chlide) a and bacteriochlorophyllide (Bchlide) a, respectively, were not affected by the mutations, but the K_m values of ChlG_I44F and BchG_F28I for the new substrates Bchlide a and Chlide a, respectively, were more than 10-fold larger than those for their original substrates, suggesting the lower affinities for new substrates. Taken together, I44 and F28 are important for the substrate specificities of ChlG and BchG, respectively. The BchG activity of ChlG_I44F and the ChlG activity of BchG_F28I further suggest that ChlG and BchG are evolutionarily related enzymes.

• Journal of applied mathematics & informatics
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• v.22 no.1_2
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• pp.403-410
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• 2006

For a finite group G, #Cent(G) denotes the number of centralizers of its elements. A group G is called n-centralizer if #Cent(G) = n, and primitive n-centralizer if #Cent(G) = #Cent($\frac{G}{Z(G)}$) = n. The first author in [1], characterized the primitive 6-centralizer finite groups. In this paper we continue this problem and characterize the primitive 7-centralizer finite groups. We prove that a finite group G is primitive 7-centralizer if and only if $\frac{G}{Z(G)}{\simeq}D_{10}$ or R, where R is the semidirect product of a cyclic group of order 5 by a cyclic group of order 4 acting faithfully. Also, we compute #Cent(G) for some finite groups, using the structure of G modulu its center.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.17 no.1
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• pp.53-58
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• 2024

This study is about the technology convergence analysis of e-commerce related patents containing Artificial Intelligence applied for in Korea. The relationships between core technologies were analyzed and visualized using social network analysis. As a result of social network analysis, the core IPC codes that make up the mutual technology network in e-commerce related patents containing Artificial Intelligence were found to be G06Q, G06F, G06N, G16H, G10L, H04N, G06T, and A61B. In particular, it can be confirmed that there is an important convergence of data processing-related technologies such as [G06Q-G06F], [G06Q-G06N], and voice and image signals such as [G06Q-G10L], [G06Q-H04N], and [G06Q-G06T]. Using this research method, it is possible to identify future technology trends in e-commerce related patents and create new Business Models.

• Journal of applied mathematics & informatics
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• v.42 no.3
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• pp.511-520
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• 2024

In this paper, we introduce the concept of split and non-split tree (D, C)- set of a connected graph G and its associated color variable, namely split tree (D, C) number and non-split tree (D, C) number of G. A subset S ⊆ V of vertices in G is said to be a split tree (D, C) set of G if S is a tree (D, C) set and ⟨V - S⟩ is disconnected. The minimum size of the split tree (D, C) set of G is the split tree (D, C) number of G, γ_χST (G) = min{|S| : S is a split tree (D, C) set}. A subset S ⊆ V of vertices of G is said to be a non-split tree (D, C) set of G if S is a tree (D, C) set and ⟨V - S⟩ is connected and non-split tree (D, C) number of G is γ_χST (G) = min{|S| : S is a non-split tree (D, C) set of G}. The split and non-split tree (D, C) number of some standard graphs and its compliments are identified.

• Toxicological Research
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• v.29 no.3
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• pp.149-155
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• 2013

G protein-coupled receptors (GPCRs) are membrane receptors; approximately 40% of drugs on the market target GPCRs. A precise understanding of the activation mechanism of GPCRs would facilitate the development of more effective and less toxic drugs. Heterotrimeric G proteins are important molecular switches in GPCR-mediated signal transduction. An agonist-activated receptor interacts with specific sites on G proteins and promotes the release of GDP from the $G{\alpha}$ subunit. Because of the important biological role of the GPCR-G protein coupling, conformational changes in the G protein upon receptor coupling have been of great interest. One of the most important questions was the interface between the GPCR and G proteins and the structural mechanism of GPCR-induced G protein activation. A number of biochemical and biophysical studies have been performed since the late 80s to address these questions; there was a significant breakthrough in 2011 when the crystal structure of a GPCR-G protein complex was solved. This review discusses the structural aspects of GPCR-G protein coupling by comparing the results of previous biochemical and biophysical studies to the GPCR-G protein crystal structure.

• BMB Reports
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• v.30 no.5
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• pp.326-331
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• 1997

To construct a competitive ELISA standard curve for the detection of glucose-6-phosphate debydrogenase (G6PD), we used highly purified native G6PD (nG6PD) as both immobilized and soluble antigens and anti-G6PD serum raised against nG6PD as antibody. The polystyrene cuvettes coated with nG6PD were challenged with a mixture of a limiting amount of anti-G6PD serum and various doses of nG6PD as competitors followed by incubation with alkaline phosphatase-anti-IgG conjugate. The competitive ELISA did not exhibit the typical sigmoidal dose-response curve characteristic of competition immunoassays under the optimal concentrations of antigen and antibody. The soluble nG6PD used as competitor failed to effectively inhibit the binding of antibodies to the immobilized nG6PD. The addition of NADP, a cofactor of G6PD enzyme, to coating buffer used for immobilizing nG6PD to the cuvettes and PBS-Tween-BSA buffer for diluting competitors did not improve the inhibition of antibody binding to immobilized nG6PD by soluble n/G6PD. The addition of BSA to coating buffer did not increase inhibition, either. Surprisingly, when partially active G6PD (paG6PD), obtained by repeated freeze-thawing, was used as competitor, the antibody binding to either immobilized nG6PD or immobilized paG6PD was inhibited 49-58%. We conclude that an effective competitive ELISA system with nG6PD enzyme and anti-G6PD serum for the detection of G6PD may not be established due to the poor inhibition of antibody binding to immobilized nG6PD by soluble nG6PD under the present assay conditions and that the inhibition may be improved by using an inactivated enzyme as competitor regardless of the type of immobilized antigen used. These results imply that the immobilized nG6PD may undergo denaturation upon binding to the polystyrene cuvettes and that our anti-G6PD serum may recognize denatured enzyme better than active enzyme.

• Korean journal of food and cookery science
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• v.18 no.2
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• pp.164-172
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• 2002

The objective of this study was to investigate the sensory and quality characteristics of Solsulgi containing different ratios of ingredients such as pine leaves power(1, 2, and 3%), sugar, and water. The results of sensory evaluation showed that Solsulgi containing 1% pine leaves powder had the higher scores in overall acceptability, color and flavor preference. In the textural analysis of Solsulgi, the springiness, chewiness, gumminess, and hardness were decreased by adding pine leaves powder. The hunter's color L value of Solsulgi was decreased by the increase of pine leaves powder. The more pine leaves powder was added, the redness and yellowness of Solsulgi were increased. The moisture content of Solsulgi was higher in the samples with 3% pine leaves powder than those with 1 %.

• Journal of applied mathematics & informatics
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• v.17 no.1_2_3
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• pp.217-227
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• 2005

Let G be a finite group and $\#$Cent(G) denote the number of centralizers of its elements. G is called n-centralizer if $\#$Cent(G) = n, and primitive n-centralizer if $\#$Cent(G) = $\#$Cent($\frac{G}{Z(G)}$) = n. In this paper we investigate the structure of finite groups with at most 21 element centralizers. We prove that such a group is solvable and if G is a finite group such that G/Z(G)$\simeq$$A_5$, then $\#$Cent(G) = 22 or 32. Moreover, we prove that As is the only finite simple group with 22 centralizers. Therefore we obtain a characterization of As in terms of the number of centralizers

• Journal of the Korean Mathematical Society
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• v.51 no.1
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• pp.55-65
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• 2014

A graph G is called a fractional (g, f, n)-critical graph if any n vertices are removed from G, then the resulting graph admits a fractional (g, f)-factor. In this paper, we determine the new toughness condition for fractional (g, f, n)-critical graphs. It is proved that G is fractional (g, f, n)-critical if $t(G){\geq}\frac{b^2-1+bn}{a}$. This bound is sharp in some sense. Furthermore, the best toughness condition for fractional (a, b, n)-critical graphs is given.

• Journal of Microbiology and Biotechnology
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• v.14 no.5
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• pp.1031-1037
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• 2004

The interaction of chemoattractant receptors and $G{\alpha}_{16}$ was studied to provide the molecular basis to elucidate the interaction of chemoattractant receptors with $G{\alpha}_{16}$ subunit, thereby possibly contributing to finding novel targets for designing new type of G protein antagonists with anti-inflammatory effects. Experiments were performed to characterize the $G{\alpha}_{16}$ subunit domains responsible for efficient coupling to chemoattractant receptors. Thus, a series of chimeric $G{\alpha}_{11}G{\alpha}_{16}$ and $G{\alpha}_{16}G{\alpha}_{11}$ cDNA constructs were expressed, and the ability of chimeric proteins to mediate C5a, IL-8, and fMLP-induced release of inositol phosphate in transfected Cos-7 cells was tested. The results showed that short stretches of residues 154 to residue 167 and from residue 174 to residue 195 of $G{\alpha}_{16}$ contribute to efficient coupling to the C5a receptor. On the other hand, a stretch of amino acid residues 220-240 of $G{\alpha}_{16}$ that is necessary for interacting with C5a receptor did not play any role in the interaction with IL-8 receptor. However, a stretch from residue 155 to residue 195 of $G{\alpha}_{16}$ was found to be crucial for efficient coupling to IL-8 receptor in concert with C-terminal 30 amino acid residues of this ${\alpha}$ subunit. Coupling profiles of a variety of chimeras, composed of $G{\alpha}_{11}G{\alpha}_{16}$ to fMLP receptor indicate that the C-terminal 30 amino acids are most critical for the coupling of $G{\alpha}_{16}$ to fMLP receptor. Taken together, $G{\alpha}_{16}$ subunit recruits multiple and distinctive coupling regions, depending on the type of receptors, to interact.