• Journal of Life Science
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• v.27 no.12
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• pp.1410-1414
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• 2017

Escherichia coli tryptophan synthase (TS) contains ${\alpha}_2{\beta}_2$, which catalyzes the final two steps in Trp biosynthesis. A molecular tunnel exists between the two active sites of ${\alpha}$ and ${\beta}$ subunits in TS. Via intersubunit communication, TS increases catalytic efficiency, including substrate channeling. The ${\beta}$ subunit of TS is composed of two domains, one of which, the COMM (communication) domain, plays an important role in intersubunit communication. The ${\alpha}$ subunit has a TIM barrel structure. This protein has functional regions at the C terminal of ${\beta}$ pleated sheets and in its loop regions. Three regions of the ${\alpha}$ subunit (${\alpha}L6$ [${\alpha}-loop$ L6], ${\alpha}L2$, and ${\alpha}L3$) are implicated in intersubunit communication. In the present study, conformational changes in ${\alpha}L6$ were monitored by measuring the sensitivity of mutant proteins in these regions to trypsin. The addition of a ${\alpha}$ subunit-specific ligand, D,L-${\alpha}$-glycerophosphate (GP), partially restored the sensitivity of mutant proteins to trypsin. In contrast, the addition of the ${\beta}$ subunit-specific ligand L-serine (Ser) resulted in varied sensitivity to trypsin, with an increase in PT53 (substitution of Pro with Thr at residue 53) and DG56, decrease in NS104 and wild type, and no change in GD51 and PH53. This finding may be related to several reaction intermediates formed under this condition. The addition of both GP and Ser led to a highly stable state of the complex. The present results are consistent with the current model. The method used herein may be useful for screening residues involved in intersubunit communication.

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.198-201
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• 2003

양모와 견과 같은 동물성 섬유는 주성분이 단백질로 구성되어 있으며 그 기본성분은 아미노산이다. 단백질섬유는 모두 동물에서 형성된 생체고분자의 일종으로서 우리 인간의 세포조성물질과 유사하여 가장 친화성이 있는 섬유라고 할 수 있다. $^{1)}$ 아미노산을 구성물질로 하는 이들의 섬유 중에는 -NH2 등의 염기성기, -COOH 등의 산성기, 그 외 -SH 등을 가지고 있으므로 광범위한 염료가 염착한다. 즉, 산성, 크롬착염, 반응, 직접, 염기성, 그리고 배트염료 등이 적용가능하다. (중략)

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2003.04a
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• pp.56-59
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• 2003

방향족 화합물이나 방향족 이종원자 고리화합물은 오각형 이종원자 고리의 이중결차에 접합되어 indole과 같은 접합된 분자가 될 수 있다. 중요한 천연물로 널리 퍼져 있는 indole 고리화합물은 생체에서 아미노산인 tryptophan으로부터 생합성된다. 양모와 견과 같은 동물성 섬유도 그 기본성분이 아미노산이며, 모두 동물에서 형성된 생체고분자의 일종으로서 우리 인간의 세포조성물질과 유사하여 가장 친화성이 있는 섬유라고 할 수 있다. (중략)

• Biomolecules & Therapeutics
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• v.8 no.4
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• pp.311-317
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• 2000

In this study we fed control diet and tryptophan supplemented diets containing 0.1,0.2,0.35% tryptophan to ICR mice for 1∼3 weeks to investigate the effects of tryptophan supplemented diet on pain sensitivity and the analgesic mechanism of serotonin. Animals fed tryptophan supplemented diets displayed increased antinociception when measured with hot plate and phenylquinone-writhing tests. And animals with typtophan supplemented diet had higher brain serotonin and 5-HIAA concentration than the control animals.

• Journal of Life Science
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• v.11 no.1
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• pp.43-47
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• 2001

A mutant tryptophan synthase $\alpha$-subunit, where Pro28 was replaced with Leu, tends to be expressed in recombinant E. coli. CD and fluorescence spectra of this protein indicate some changes in secondary and tertiary structure. Wild type protein was more or less affected by {TEX}$Ca^{2+}${/TEX} ion in regards of the fluorescent properties of its native, unfolded and intermediate forms, but the mutant protein was not at all. The dramatic structural changes may be related to the aggregation of this mutant protein.

• Korean Journal of Microbiology
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• v.23 no.1
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• pp.9-12
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• 1985

As a part of the host cell development for a amplified recombinant trp operon, $aroP^-$ mutation was introduced in a E. coli host strain. $aroP^-$ mutation was induced by transposon Tn10 and transduced into the E. coli host cell by bacteriophage P1Kc. The effect of $aroP^-$ mutation on the excretion of tryptophan in E. coli $trpR^{-ts}/ColE_1 -trp^+$ cells was investigated. Mutant lacking the general aromatic transport system was resistant to ${\beta}-2-thienylalanine\;(2{\times}10^{-4}\;M)$, p-fluorophenylalanine $(2{\times}10^{-4}M)$, or 5-methyltryptophan $(2{\times}10^{-4}\;M.)[^3H]-tryptophan$ uptake of the $aroP^-$ mutant strain was reduced considerably as compared with $aroP^+$ counterpart. The rate of $[^3H]-tryptophan$ uptake of the $aroP^-$ mutant strain treated with $NaN_3(3{\times}10^{-2}\;M)$ was much less affected than that of $aroP^+$ counterpart. The $aroP^-$ transductants increased the tryptophan excretion from E. coli $trpR^{-ts}/ColE_1 -trp^+$ four times more than $aroP^+$ counterpart.

• Korean Chemical Engineering Research
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• v.43 no.5
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• pp.603-608
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• 2005

The molded macroporous poly (glycidyl methacrylate-co-ethylene glycol dimethacrylate) rods produced by a facile molding process were polymerized in situ within a tubular mold, chromatographic column ($4.6{\times}100mm$) by free radical polymerization. It was complemented by epoxy derivatized monolithic column and chemical modification of the epoxide groups with the sulphuric acid. By variation of the polymerization conditions, such as the ratio of the monomers, the porogen (pore generating material), and the temperature, the pore size could be varied, so the retention time of the samples may be adjusted. For the mixture of caffeine and tryptophan in the prepared monolithic column, the influences of polymerization material compositions to the efficiency, selectivity, and resolution of the monolithic column were investigated.

• Korean Journal of Biological Psychiatry
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• v.11 no.2
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• pp.136-145
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• 2004

Objectives:Genetic variations of the tryptophan hydroxylase(TPH) gene and the serotonin transporter linked polymorphic region(5-HTTLPR) polymorphism have been associated with its functional capacity. The authors investigated whether the allelic constitution of the TPH gene and 5-HTTLPR are associated in Korean panic patients. Methods:244 Korean patients with panic disorder and 227 normal healthy controls were tested for a genetic polymorphism of TPH A218C and 5-HTTLPR polymorphism. To assess the severity of panic disorder during the last one month, anticipatory anxiety, panic difficulty, panic distress, agoraphobic difficulty and agoraphobic distress were measured with visual analogue scale(VAS) score, STAI-S & T, BDI, SCL-90-R, ASI-R, CGI, PDSS, and HAMD. Results:There was no significant difference in genotype and allele frequencies of TPH A218C and 5-HTTLPR polymorphism between panic patients and controls. Although we observed some differences in genotype and allele frequencies of TPH A218C polymorphism among male subjects, these differences disappeared after Bonferroni correction. And there were no significant differences in clinical variables. Conclusion:Our results suggested that there are no association between the genetic polymorphism of TPH gene and 5-HTTLPR with panic disorder.

• Journal of the Korean Chemical Society
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• v.31 no.5
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• pp.400-405
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• 1987

The two dissociation constants of three amino acid, glycine, alanine, and tryptophan were measured by the conductometric method in the temperature from 15 to 35$^{\circ}$C and pressure up to 2,500bar in aqueous solution. The both dissociation constants were increased as the temperature increased but the pressure effect were not same as the temperature effect. The first constants were increased as the pressure increased but second constants were decreased except tryptophan. The characteristic properties of these amino acids were discussed from the thermodynamic properties of the dissociation reaction. The substituted effects of the reaction were deduced from Hammett reaction and substituted constants which were calculated from the dissociation constants.

• Journal of Life Science
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• v.14 no.2
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• pp.252-254
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• 2004

The mutant tryptophan synthases at $\alpha$Asp$^{56}$ have low catalytic activities. The enzymes were treated with $\alpha$ and $\beta$ subunit-specific ligands in the presence of L-serine and indoline. It was shown that the cations resulted in changes of absorbance patterns among the proteins, while glycerophosphate showed similar pattern of absorbance. The glycerophosphate binds to the active site of $\alpha$ subunit so that $\alpha$Asp$^{56}$ may not be involved in the allosteric control with the active site of $\alpha$ subunit occupied by substrate. The results suggest that $\alpha$Asp$^{56}$ may playa role in the step of a series of reaction occurring without bound substrates in the active site of asubunit.