• 약학회지
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• 제36권5호
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• pp.469-473
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• 1992

Yeast alcohol dehydrogenase (YADH) has an acidic residue that interacts with the 2'- and 3'-hydroxyl groups of the adenosine ribose of the $NAD^+$ coenzyme. The acidic residue of Asp-223 (according to horse liver alcohol dehydrogenase amino acid sequence) is supposed to determine the coenzyme specificity for $NAD^+$ rather than $NADP^+$. We mutated Asp-223 to leucine and the mutant YADH was expressed in yeast and characterized for the coenzyme specificity. The turnover numbers of mutant enzyme for $NAD^+$ and ethanol were decreased 3.5- and 4.8-fold compared to wild-type enzyme, respectively. Contrastively, catalytic specificity for $NADP^+$ was increased 13-fold. As a result, the mutant YADH also employed $NADP^+$ as a coenzyme.

• Bulletin of the Korean Chemical Society
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• 제29권12호
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• pp.2499-2501
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• 2008

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2001년도 학술 발표회 진행표 및 논문초록
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• pp.33-33
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• 2001

Bacterial Δ$\^$5/-3-ketosteroid isomerase (KSI) is one of the most proficient enzymes catalyzing the isomerization of a variety of Δ$\^$5/-ketosteroids to Δ$^4$-ketosteroids at a diffusion-controlled rate. Because of the simplicity of the reaction, the enzyme mechanism has been intensively studied as a prototype to understand enzyme-catalyzed C-H bond cleavage.(omitted)

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 1999년도 학술발표회 진행표 및 논문초록
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• pp.35-35
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• 1999

Amylases catalyze the hydrolysis of starch material and play central roles in carbohydrate metabolism. The structure and a size exclusion column chromatography proved that the enzyme is a dimer in solution. The N -terminal segment of the enzyme folds into a distinct domain and comprises the enzyme active site together with the central (${\alpha}$/ ${\beta}$)$\sub$8/ barrel of the adjacent subunit.(omitted)

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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• pp.475-479
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• 1996

At present studies, we are going to suggest the new type of Perovskite derived catalysts which modify the defects of transition metals impregnated. Perovskite type catalyst is a typical mixed metal oxides, and there are "defect"s (from like that oxygen, cation, crystallic structure) were made by difference from composition, preparing method and so forth. And because this, its electro-magnetic character could be much changed. By using this phenomena, it could utilize the modification of adsorption/desorption characters as well as the catalytic activities in NOx reduction. Because perovskite type catalyst can exchange the metal of the each lattice site freely and it is possible to represent the peculiar.

• Molecules and Cells
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• 제39권1호
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• pp.1-5
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• 2016

Peroxiredoxins (Prxs) are a very large and highly conserved family of peroxidases that reduce peroxides, with a conserved cysteine residue, designated the "peroxidatic" Cys ($C_P$) serving as the site of oxidation by peroxides (Hall et al., 2011; Rhee et al., 2012). Peroxides oxidize the $C_P$-SH to cysteine sulfenic acid ($C_P$-SOH), which then reacts with another cysteine residue, named the "resolving" Cys ($C_R$) to form a disulfide that is subsequently reduced by an appropriate electron donor to complete a catalytic cycle. This overview summarizes the status of studies on Prxs and relates the following 10 minireviews.

• Bulletin of the Korean Chemical Society
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• 제16권5호
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• pp.398-400
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• 1995

Selective oxidation of cyclohexane in acetone solution has been studied using iron catalysts with hydrogen peroxide in-situ produced by palladium catalyst. Iron tetraphenylporphyrin chloride shows the highest activity among the tested chlorides and porphyrin complexes of some metals of the first transiton series. Iron chloride and iron tetraphenylporphyrin chloride were supported on four kinds of 4-vinylpyridine copolymer with styrene or divinyl-benzene. Nitrogen 1s photoelectron spectra give the evidence that pyridyl nitrogens of the 4-vinyl pyridine copolymer act as ligands to bind iron species. The copolymer with styrene is the most efficient support for the binding because its solubility in catalyst preparation solvent (methylene chloride) gives the pyridyl group advantage to contact with the iron catalysts. However, better catalytic activity per iron atom could be obtained with a rigid crosslinked polymer due to active site isolation.

• 한국표면공학회지
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• 제52권3호
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• pp.150-155
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• 2019

The carbon electrode was modified through manganese-catalyzed hydrogenation method for high energy density vanadium redox flow battery (VRFB). During the catalytic hydrogenation, the manganese oxide deposited at the surface of the carbon electrode stimulated the conversion reaction from carbon to methane gas. This reaction causes the penetration of the manganese and excavates a number of cavities at electrode surface, which increases the electrochemical activity by inducing additional electrochemically active site. The formation of the porous surface was confirmed by the scanning electron microscopy (SEM) images. Finally, the electrochemical performance test of the electrode with the porous surface showed lower polarization and high reversibility in the cathodic reaction compared to the conventional electrode.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.187.2-187.2
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• 2003

The cyclin-dependent kinases (CDKs), a group of serine/threonine kinases that form active heterodimeric complexes binding to cyclins, are key regulators of the cell cycle. The role of cyclin dependent kinases(CDKs) in cell cycle regulation has stimulated an interest in them as potential targets for proliferative diseases such as cancer, psoriasis, and chemotherapeutic agent-induced alopecia. Indirubin, an active ingredient of a traditional Chinese recipe Danggui Longhui Wan, are potent CDK inhibitors competing with ATP for binding to the catalytic site of the CDKs. (omitted)

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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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)