• BMB Reports
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• 제34권4호
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• pp.299-304
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• 2001

The 3-Deoxy-D-arabinoheptulosonate 7-phosphate (DAHP) synthase is the first enzyme of aromatic amino acid-, folic acid-, and phenazine-1-carboxylic acid biosynthetic pathways. DAHP synthase of Bacillus sp. B-6 that produces phenazine-1-carboxylic acid was feedback inhibited by two intermediary metabolites of aromatic amino acid biosynthetic pathways, prephenate and chorismate, but not by other metabolites, such as anthranilic acid, shikimic acid, p-aminobenzoic acid, and 3-hydroxyanthranilic acid. DAHP synthase of Bacillus sp. B-6 was not inhibited by end products, such as aromatic amino acids, folic acid, and phenazine-1-carboxylic acid. The inhibition of DAHP synthase by prephenate and chorismate was non-competitive with respect to erythrose 4-phosphate and phosphoenolpyruvate. Prephenate and chorismate inhibited 50% of the DAHP synthase activity at concentrations of $2{\times}10^{-5}\;M$ and $1.2{\times}10^{-4}\;M$, respectively The synthesis of DAHP synthase of Bacillus sp. B-6 was not repressed by exogenous aromatic amino acids, folic acid, and phenazine 1-carboxylic acid, single or in combinations.

• 한국미생물·생명공학회지
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• 제22권6호
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• pp.636-642
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• 1994

Essential amino acids involving in the catalytic mechanism of the $\beta$-D-xylosidase of Bacillus stearothermophilus were determined by chemical modification studies. Among various che- mical modifiers tested N-bromosuccinimide (NBS), $\rho$-hydroxymercurybenzoate (PHMB), N-ethylma- leimide, 1-[3-(di-ethylamino)-propyl]$-3-ethylcarbodi-imide (EDC), and Woodward's Reagent K(WRK)inactivated the enzyme, resulting in the residual activity of less than 20%. WRK reduced the enzyme activity by modifying carboxylic amino acids, and the inactivation reacion proceeded in the form of pseudo-first-order kinetics. The double-lagarithmic plot of the observed pseudo-first- order rate constant against the modifier concentration yielded a reaction order of 2, indicating that two carboxylic amino acids were essential for the enzyme activity. The $\beta$-D-xylosidase was also inactivated by N-ethylmaleimide which specifically modified a cysteine residue with a reaction order of 1, implying that one cysteine residue was important for the enzyme activity. Xylobiose protected the enzyme against inactivation by WRK and N-ethylmaleimide, revealing that carboxylic amino acids and a cysteine residue were present at the substrate-binding site of the enzyme molecule.

• 대한화학회지
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• 제14권2호
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• pp.161-168
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• 1970

In order to obtain the more effective evidence, supporting the hypothesis which have been previously described by former report that pepsin (EC 3.4. 4.1) forms a hydrophobic bond with the nonpolar side chain of its substrate, the inhibitory effect of carboxylic acids(from formic acid to iso-butyric acid) on the activity of pepsin to the synthetic dipeptide, N-Carbobenzoxy-L-glutamyl-L-tyrosine, was discussed. The kinetic study showed that the inhibition by carboxylic acids was competitive. The Kidecreased with increasing size of the inhibitor molecule. The $-{\Delta}F^{\circ}$increased linearly with increasing number of carbon atoms in the hydrocarbon chain of the inhibitor. It was confirmed that the hydrophobic bond between more than one side chain of amino acid residues(phenylalanine) in the binding region of the active center of pepsin and the side chain of amino acid residues in the substrate was formed as the first step of its enzymic mechanism. The inhibitory effect of carboxylic acids was due to the competition of the hydrocarbon group of the carboxylic acids with the side chain of the substrate for the hydrophobic binding site(the side chain of phenylalanine) of the pepsin.

• Journal of Microbiology and Biotechnology
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• 제9권4호
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• pp.381-385
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• 1999

Taq DNA polymerase from Thermus aquaticus has been shown to be very useful in a polymerase chain reaction. Taq DNA polymerase has a domain at the amino terminus (residues 1 to 290) that has 5'-3' exonuclease activity and a domain at the C-terminus that catalyzes the polymerase reaction. Taq DNA polymerase is classified into the Pol I family, which is represented by E. coli DNA polymerase I. The alignment of amino acid sequences for the 5'-3' exonuclease domains of the Pol I family DNA polymerases shows ten highly conserved carboxylic amino acids. Crystallographic studies suggested that six of the carboxylic amino acids are clustered within a 7 $\AA$ radius by chelating three metal ions in the active site. Those six carboxylic residues are mutagenized to alanines in order to better understand their function. All six carboxylic residues, Asp l8, Glu1l7, Asp1l9, Asp120, Asp142, and Aspl44, are crucial for catalysis of 5'-3' exonuclease.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.241-241
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• 2006

Absolute configuration of carboxylic acids, including amino acids can be determined by circular dichroism (CD) exciton chirality method. This method employs cyclic oligopyrroles able to form stable complexes with carboxylic acids. Addition of carboxylic acids to the oligopyrroles induce CD spectrum at the macrocycle absorption region and in which the sign of the $1^{st}$ Cotton effect is determined solely by the absolute configuration of the carboxylic acid. The basicity of the pyrrole nitrogen can be controlled by macrocycle substitution thus yielding more sensitive chirality sensors.

• 약학회지
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• 제27권4호
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• pp.289-293
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• 1983

Twelve new N-piperoyl amino acids were synthesized by acylation of amino acids with piperoylchloride in order to develop the new central nervous depressants. Silylation of the carboxylic group of amino acids not only precluded side reactions but-also facilitated acylation at room temperature without catalysts. The acute toxicity of all the synthesized compounds were lower than that of piperine itself, whereas they showed strong protective effect against the strychnine-induced mortality.

• 생명과학회지
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• 제13권6호
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• pp.943-949
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• 2003

7번 위치에 하롤겐이 치환된 여로종류의 퀴놀론 모핵과 시스 또는 트란스-3-아미노-4-메틸오메틸피롤리딘을 반응시켜 7-(시스 또는 트란스-3-아미노-4-메틸티오메틸피롤리디닐) 퀴롤론-3-카르복실산의 신규 항균제를 합성하였다. 새롭게 합성된 퀴놀론의 약효는 그람양성균에 대해 대조물질인 시프로플로삭신보다 매우 탁월하였고, 녹농균이외의 그람음성균에 대해서도 대조물질과 거의 유사하였다. 그리고 임상에서 문제가 되고 있는 메티실린 내성 포도상구균(MRSA)에 대한 신규 퀴놀론의 약효는 더욱더 향상되어진 것으로 나타났다.

• 대한화학회지
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• 제41권4호
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• pp.214-218
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• 1997

• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book II
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• pp.145-148
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• 2003

Previously, we reported that L-PCA enhanced blood circulation by modulating constitutive NO production. It was that L-PCA increased L-Arg uptake into endothelial cell, followed by the enhancement of NO production. Then we recommended the use of L-PCA for cosmetics, not only as humectants but also as enhancer of blood circulation. Since L-Arg is transported into endothelial cells by CAT (cationic amino acid transporter), it is expected that L-PCA also increase the uptake of basic amino acid, L-Lys. In this study, the uptakes of some amino acids into cells were evaluated by using 3H-labelled amino acid. Then we found the tendency that the uptake of L-Lys into endothelial cells was also enhanced by L-PCA. And the evident effect was observed in the epidermal fibroblasts, which had also CAT. Furthermore, it was found that the transportation of the other type of amino acids were not enhanced by L-PCA. That is to say, a famous moisturizer, L-PCA, has some effects on basic amino acid transport into cells.

• Korean Chemical Engineering Research
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• 제58권3호
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• pp.474-479
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• 2020

유리기판의 박막화를 위한 식각액을 제조하였고, 습식 식각액의 주성분으로 HF를 사용하였다. HF를 기본으로 한 식각액에 HCl, HNO₃, H₂SO₄와 같은 강산과 구연산과 같은 카르복실산 그리고 여러 종류의 아미노산을 첨가물로 각각 사용한 식각액으로 유리의 식각속도와 표면형상의 변화를 측정하였다. 강산의 종류와 상관없이 첨가량이 증가함에 따라 선형적으로 유리의 식각속도가 증가하였으며 유리표면의 슬러지 제거효과도 나타내었다. HCl이 함유된 식각액이 식각속도의 증가율과 슬러지 제거 효과에서 다른 강산보다 효율적인 결과를 보였다. 카르복실산의 첨가는 식각속도에 영향을 크게 주지 않으나 슬러지 제거효과를 보였다. 하지만 아미노산을 첨가한 경우에는 식각속도의 변화와 슬러지 제거 효과가 크지 않았다.