• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.1
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• pp.35-39
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• 1991

Properties of a protease purified from Neungee[Sarcodon aspratus(Berk, ) S. Ito] have been investigated. The enzyme displays a glycosylated serine protease. The enzyme is able to hydrolyze alanine glycine methionine glutamine and cysteine of N-CBZ and N-t-BOC-L-amino acid derivatibes relatively strongly but splits valine proline and isoleucine derivatives with low affinity which means the enzyme has the broad substrate spectrum toward the amino acids. Interestingly the enzyme was inhibited by bromelain inhibitor. That is the active site environ-ment of the enzyme is believed to be similar to that of bromelain However peptide mapping studies show that the two enzymes have distinct different cleavage sites.

• BMB Reports
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• v.29 no.3
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• pp.236-240
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• 1996

A 23-kDa molecular mass of antioxidant protein was purified from human liver. This protein exhibited the preventive effect against the inactivation of glutamine synthetase by a metal-catalyzed oxidation system. This antioxidant activity was supported by a thiol-reducing equivalent such as dithiothreitol in a similar manner to that of the 25-kDa thiol-specific antioxidant protein (TSA) from human red blood cells (HR). However, a thioredoxin-linked peroxidase activity of thiol-specific antioxidant protein of human liver (HLTSA) (0.91 ${\mu}mol/min/nmol$ of HLTSA) was much lower than that of thiol-specific antioxidant protein of human red blood cells (HRTSA) (16.4 ${\mu}mol/min/nmol$ of HRTSA). This HLTSA is also immnologically distinct from HRTSA Amino acid sequences of the three tryptic peptides (P1, P2, P3) of HLTSA were found to be completely homologous to segments of the known Mer5-like protein, which belongs to the known TSA family.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2005.09a
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• pp.221-227
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• 2005

THEMATICS is a simple computational method for predicting functional sites in proteins. The method computes the theoretical titration curves of the ionizable residues of a protein using its 3D structure, determines the residues with perturbed, non-Henderson-Hasselbalch titration behavior, and identifies clusters of these perturbed residues in physical proximity. We have shown previously that this method is highly successful in predicting catalytic sites in enzymes. In the present study, we apply the method to non-catalytic ligand-binding proteins. It is shown that THEMATICS can predict non-catalytic binding sites. The success rate is better than 80 % for a set of 30 non-catalytic, ligand-binding proteins. The application of the method to Glutamine-binding protein from E. coli is discussed in detail.

• Korean Journal of Microbiology
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• v.26 no.2
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• pp.93-100
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• 1988

In order to understand the regulation of glutamate dehydrogenase(GDH) synthesis in Brevibacterium flavum, we have isolated a mutant lacking NADP-linked GDH activity by ethlmethane sulfonate treatment. The $gdh^-$ mutant was grown on the minimal plate with 1mM ammonium chloride and not that with 300mM ammonium chloride. The cell-free extracts from $gdh^-$ mutant and prototroph were also examined with glutamine synthetase(GS) and glutamate synthase (GOGAT) production by niteogen sources. The growth of $gdh^-$ mutant in presence of 20mM ammonium chloride means that GOGAT synthesis is sufficient to allow growth in this condition. GS production of $gdh^-$ mutant as well as parental strain was induced by 1mM urea and ammonium tartrate, but it was repressed by higher concentration of ammonia, and also induced by 20mM to 50mM glutamate as a substrate. It was special attention that GOGAT synthesis from $gdh^-$ strain was more repressed by higher concentration of ammonia than prototroph as described in E. coli system.

• Microbiology and Biotechnology Letters
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• v.21 no.6
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• pp.527-533
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• 1993

Aminolevulinic acid(ALA) was shown to be synthesized via active pathways of either C4 or C5 ALA biosynthesis in cells of a photosynthetic bacterium, Rhodocyclus gelatinosus KUP-74, where the C5 pathway was appeared to be preferntially expressed in the cells. It was strongly suggested that L-glutamine might be utilized more effectively than L-glutamate to synthesize ALA via C5 pathway in this bacterium from the fact of relationship between the cellular uptake rates of glutamate and its Gamma-derivaties and corresponded ALA productivities in vitro and in vivo.

• Journal of Plant Biology
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• v.32 no.4
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• pp.235-245
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• 1989

The contents and the compositions of total free amino acids were investigated in the rice(Oryza sativa L. cv. Chuncheong) seedlings under low temperatures. Activities of some enzymes associated with the markedly changed amino acid content were also investigaetd. Under low temperature, the contents of soluble protein and the total free amino acids increased, while the content of total nitrogen decreased. Although asparagine＋glycine were the most abundant amino acid speceis in the rice seedlings at the control temeprature, low temperature treatment for 3days brought about the decrease in their amount to about 60% level of the control plants. On the other hand, alanine showed the highest increase in the content among all the free amino acids, though glutamine, proline, asprtic acid, valine and tyrosine also increased after low temperature treatment. To eludicate the decrease of asparagine＋glycine level under low temperature, the activities of asparagine aminotransferase and asparaginase which metabolize asparagine were investigated in the rice seedlings under low temperature. The activity of asparaginase increased markedly, while that of asparagine aminotransferase decreased under low temperatures. Therefore, it was suggested that asparaginase metabolizes asparagine predominatly in the rice seedlings under low temperatures.

• Korean Journal of Microbiology
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• v.15 no.3
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• pp.131-138
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• 1977

The effects of various nitrogen soruces on the expression of nif gene were investigated using nif-lac fusants of Klebsiella pneumoniae. K. pneumoniae UK 2979 was infected with Mudl lysate prepared by heat induction of K. pneumoniae UK 4482. About 80 nif-lac fusants were greatly repressed. Amino acids, such as serine, glutamine and asparagine, were found to support the growth of K. pneumoniae M5al quite well, and showed a repressive effect on .betha.-galactosidase activities of nif-lac fusants LX-9 and LX-22 in NFHM. Glutamic acid, histidine and arginine rendered poor growth but high activities of .betha.-galactosidase. Good cell growth and high enzyme activity were observed when complex nitrogen sources, such as casitone, proteose pepone, were employed. .betha.-Galactosidase activities of LX-9 and LX-22 in nitrogen free minimal medium increased sharply within first 4 hours.

• Bulletin of the Korean Chemical Society
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• v.32 no.9
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• pp.3367-3371
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• 2011

An easy and convenient synthetic route to (S)-2-hydroxy-2'-(3-phenyluryl-benzyl)-1,1'-binaphthyl-3-carboxaldehyde (1), capable of recognizing tryptophan by fluorescence has been developed. The binol carboxaldehyde 1 exhibited a high selectivity to L-tryptophan over other examined L-${\alpha}$-amino acids such as alanine, phenylalanine, glutamine, arginine, lysine, serine, threonine, aspartat, valine, histidine and cysteine, with a fluorescence "turn-on" signal. In addition, 1 displayed chiral discrimination with good enantioselectivity toward L-tryptophan over D-tryptophan through different fluorescence enhancement factors.

• Environmental Mutagens and Carcinogens
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• v.8 no.1
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• pp.22-34
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• 1988

The biochemical changes of the hepatic tissues, induced by the carcinogen treatment such as diethylnitrosamine and acetamidofluorene in combination with the partial hepatectomy after Solt and Farber, were determined for the characterization of the induction of the proliferative capacity and the environmental adaptability of the carcinogenic tissues during the malignant transformation process. For the study of the proliferative capacity of the tissues, the activities of the enzymes, related with the nitrogen trapping mechanism, such as glutamine synthetase and gamma-glutamyltranspeptidase, were monitroed, while the cintents of cytochrome P450's and their isozymic patterns as well as the activities of the glutathione S-transferase were determined in the function of time after the hepatocarcinogenic stimuli.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.680-683
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• 2000

A cytochrome c-552 from a thermophilic hydrogen-oxidizing bacterium, Hydrogenobacter thermophilus, was amplified using PCR. The cytochrome c-552 gene was cloned into E. coli vector pAlter-1 and transferred to JM109. Glutamine of cytochrome c-552 protein was changed to cysteine through point mutation.