• Journal of Plant Biology
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• 제32권4호
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• pp.285-292
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• 1989

The intracellular localizations of polyamines and their related enzymes were investigated from young spinach leaves. Polyamines were present in all parts of plant cells, both in the subcellular organelles and in the soluble fraction of cytoplasm, however, polyamines were mainly located in the cytosolic fraction. Most activities of L-arginine decarboxylase(ADC) and L-ornithine decarboxylase(ODC), two important enzymes of putrescine and polyamine biosynthesis, were detected in cytosol fraction, while in subcellular organelles the activities were very low. Activities of diamine oxidase(DAO) and polyamine oxidase(PAO), the catabolic enzyme of diamine and polyamine, were not detected in spinach leaves. It was suggested that polyamines and their related synthetic enzymes were located in the soluble fraction of cytoplasm.

• Journal of Plant Biology
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• 제33권4호
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• pp.243-251
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• 1990

Polyamine titers and the activities of arginine decarboxylase(ADC) and ornithine decarboxylase (ODC), enzymes which catalyze rate-limiting steps in polyamine biosynthesis, were investigated during polar regeneration of Populus leaf segments. The polar regeneration occurred at the basal cut end of Populus leaf segments through cell division around the vascular bundle. In the process of polar regeneration, the titers of putrescine and spermidine increased rapidly but the content of spermine remained constant. The leaf segments were then divided into three separte part ; the proximal, middle and distal. Spermidine titers showed an increase mainly in the proximal parts where polar regeneration occurred. On the other hand, putrescine titers showed an increase in the other two parts. In the course of polar regeneration, the activities of ADC and ODC increased, the ADC activities being higher than those of ODC. However, ODC activity was higher in the proximal part. Therefore, the spermidine contents and ODC activities are suggested to be related to polar regeneration in Populus leaf segments.

• Bulletin of the Korean Chemical Society
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• 제19권2호
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• pp.189-193
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• 1998

Carboxypeptidase-B (CPB) is involved in the biosynthesis of numerous peptide hormones and neurotransmitters. CPB catalyzes hydrolysis of the basic amino acids from the C-terminal position in polypeptides during posttranslational prohormonal processing. Various peptides containing thiaarginine residue at C-terminal position were synthesized and tested for their hydrolysis by CPB. A colorimetric assay, employing Ellman's reagent to detect the thioguanidine released upon hydrolysis of the dipeptide substrates, showed that thiaarginine is a suitable mimetic for arginine. Kinetic studies on the four substrates, Z-L-Ala-DL-thia-Lys, Z-L-Ala-DL-thia-Arg, Z-L-Lys-DL-thia-Arg, and Z-L-Lys(Boc)-DL-thia-Arg, gave Km (mM) of 0.66, 5.08, 0.024, and 0.006 and kcat (min-1) of 340, 5200, 151 and 335, respectively.

• Applied Biological Chemistry
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• 제39권2호
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• pp.112-117
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• 1996

ADC는 diamine인 putrescine 생합성의 두가지 경로중에서 식물계에서 특히 중요한 효소이며, ADC 유전자는 E. coli, 귀리, 토마토 genome에서 이미 cloning된 바 있다. 벼 (Oryza sativa L.) 게놈 DNA의 PCR 증폭을 위해서 토마토와 E. coli의 ABC cDNA의 보존된 부분과 일치하는 두개의 degenerate oligonucleotides (17mer)를 인위 합성하였으며, 증폭의 결과 약 1 kbp 크기의 DNA가 관찰되었다. 증폭된 DNA 절편은 1,022bp 염기서열을 포함하고 있는 ORE (open reading frame)으로 확인되었다. 이 PCR product는 POEM-originated T vector에 재조합하였으며 PstI 제한효소로 약 500bp 크기로 절단하여 pGEM-3Zf(+/-) vector에 subcloning하였다. 벼 ADC clone의 염기서열은 귀리와 토마토 ADC cDNA 서열의 같은 부분과 각각 74%와 70%의 동질성을 갖는 것으로 나타났으며, 예상되는 아미노산 서열은 귀리와 토마토 ADC 단백질과 각각 45%와 62%의 동질성이 관찰되었다. 귀리와 E. coli, 토마토와 귀리 그리고 토마토와 E. coli ADC 아미노산 서열에서 각각 34%, 47%, 그리고 38%의 유사성 정도가 보고된 것을 비교하여 볼 때, 벼와 귀리 및 토마토 사이의 유사성 정도는 다른 비교 보다도 월등히 높았다. 벼 유묘기 잎조직에서 추출한 RNA를 이용한 Northern blot 분석에서 ADC는 약 2.5kbp의 전사체로 발현됨이 확인되었다.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1996년도 춘계학술대회
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• pp.217-217
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• 1996

The putative role of vasoactive intestinal polypeptide (VIP) as non-adrenergic non-cholinergic (NANC) neurotransmitter has been studied in rabbit corpus cavernosum. In the presence of atropine and guanethidine the short and prolonged electrical field stimulation (EFS, 2～16 ㎐) induced a frequency-dependent relaxation which was abolished by tetrodotoxin (0.3 ${\mu}$M), a nerve conductance blocker. The neurogenic relaxant reponses were not affected in the presence of VIP-inactivating peptidase, ${\alpha}$-chymotrypsin (2 units/$m\ell$), whereas VIP-induced relaxation were completely abolished. Inhibition of nitric oxide synthase by N$\^$G/-nitro-L-arginine (10～100 ${\mu}$M) caused concentration-dependent inhibition to the neurogenic relaxant responses and at 100 ${\mu}$M the relaxations were virtually abolished. In contrast NO (3～30 ${\mu}$M) and VIP (0.001～l ${\mu}$M)-induced relaxation were unaffected. The inhibitory effect of L-NNA was reversed in the presence of L-arginine (5 mM), the precursor of the NO biosynthesis. Hemog1obin (20～60 ${\mu}$M), sequestering NO in the extracellular space, abolished the NO-evoked relaxation and also caused a concentration-dependent inhibition to the neurogenic relaxation. These observation indicate that NANC relaxation induced by prolonged EFS of rabbit corpus cavernosum is also mediated mainly by nitric oxide as same as that of short EFS, and suggest that VIP is not involved in NANC relaxation of rabbit corpus cavernosum and NO would not be produced by VIP in this tissue.

• 한국미생물·생명공학회지
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• 제50권4호
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• pp.522-532
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• 2022

Cheonggukjang is a traditional fermented food in Korea, which is known to exert beneficial effects on health. In this study, we evaluated the effects of cheonggukjang fermented by Bacillus subtilis SCGB 574 (B574) on high fat diet (HFD)-deteriorated large intestinal health. Rats were fed with HFD or HFD supplemented with 10.1% cheonggukjang (B574). Fecal microbiota was analyzed based on 16S rRNA gene sequences, and the fecal and serum metabolome were measured using GC-MS. Our results showed that SCGB574 intake significantly reduced body weight, restored tight junction components, and ameliorated inflammatory cell infiltration. SCGB574 also shifted gut microbiota by increasing the abundance of short chain fatty acid producers such as Alistipes and Flintibacter, although it decreased the abundance of Lactobacillus. Serum and fecal metabolome analyses showed significantly different metabolic profiles between the groups. The top five metabolites increased by SCGB574 were i) arginine biosynthesis, ii) alanine, aspartate, and glutamate metabolism; iii) starch and sucrose metabolism; iv) neomycin, kanamycin, and gentamicin biosynthesis; and v) galactose metabolism. These results showed that cheonggukjang fermented by SCGB574 ameliorates adverse effects of HFD through improving intestinal health.

• 한국동물학회지
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• 제39권3호
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• pp.299-306
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• 1996

항 대사물질 6-aminonicotinamide가 메추리 조직의 수용성 단백질, 유리 아미노산 및 단백질 가수분해효소에 미치는 영향을 조사하였다. 간(P<0.05), 심장(P<0.01), 흉부근육 조직(P<0.05)의 수용성 단백질의 함량은 대조군에 비해 현저히 감소하였다. 신장과 흉부근육 조직의 단백질 가수분해효소의 비활성도는 대조군에 비하여 현저히 감소하였다. 신장과 흉부근육 조직의 단백질 가수분해효소의 비활성도는 대조군에 비해 현저히 증가하였다. (P<0.05). 간(P<0.05)의 aspartic acid / asparagine, alanine, valine, methionine, isoleucine, leucine, lysine의 농도는 대조군에 비해 증가하였다. 신장(P<0.05)의 acid / asparagine, alanine, threonine, alanine, proline과 lysine은 증가하였으나 glutamic acid / glutamine의 농도는 감소하였다. 심장에서는 glycine과 methionine 농도는 증가하였으나 glutamic acid / glutamine의 농도는 감소하였다. 흉부근육 조직에서는 arginine의 농도는 감소하였으나 (P<0.05) alanine과 threonine의 농도는 증가하였다 (P<0.05). 본 연구 결과는 항 대사물질인6-aminonicotinamide가 유리 아미노산의 농도를 증가시키므로써 기포 물질 대사에 필요한 에너지를 유지하는 것으로 사료된다.

• Journal of Microbiology and Biotechnology
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• 제13권4호
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• pp.560-563
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• 2003

During our previous studies on the relationship between nutrient requirements of S. hygroscopicus C9 and rapamycin biosynthesis, we developed chemically-defined media containing among other nutrients, aspartic acid, arginine, histidine, or ammonium sulfate. However, these media (“Cheng et al. medium” and “Lee et al. medium”) showed very slow growth characterized by a very long lag phase of growth. In an attempt to develop a chemically-defined or semi-defined medium to support more rapid growth and increased cell production, we have carried out studies to shorten the lag phase. Of the various additives tested, vitamin-free casein acid hydrolysate was the most significant by shortening the lag phase by 2-3 days. Mixtures of amino acids failed to replace casein acid hydrolysate. The active principle passed through an ultrafilter with a molecular weight cutoff of 1,000 and thus may be a peptide. The present work has yielded a semi-defined medium which should be useful for further growth studies on S. hygroscopicus C9.

• BMB Reports
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• 제43권6호
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• pp.419-426
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• 2010

Aeromonas hydrophila is a bacterial pathogen that infects a large number of eukaryotes, including humans. The UDP-galactose 4'-epimerase (GalE) catalyzes interconversion of UDP-galactose to UDP-glucose and plays a key role in lipopolysaccharide biosynthesis. This makes it an important virulence determinant, and therefore a potential drug target. Our earlier studies revealed that unlike other GalEs, GalE of A. hydrophila exists as a monomer. This uniqueness necessitated elucidation of its structure and active site. Chemical modification of the 6xHis-rGalE demonstrated the role of histidine residue in catalysis and that it did not constitute the substrate binding pocket. Loss of the 6xHis-rGalE activity and coenzyme fluorescence with thiol modifying reagents established the role of two distinct vicinal thiols in catalysis. Chemical modification studies revealed arginine to be essential for catalysis. Site-directed mutagenesis indicated Tyr149 and Lys153 to be involved in catalysis. Use of glycerol as a cosolvent enhanced the GalE thermostability significantly.

• 약학회지
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• 제41권3호
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• pp.389-398
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• 1997

Non-adenergic non-cholinergic (NANC) innervation on the circular muscle of the rabbit gastric body was investigated by observing the magnitudy of relaxations induced by the elec trical field stimulation (EFS). Strips were cut from the greater curvature of the gastric body and stimulated with 5s trains of 0.5 ms pulses at 1-20 Hz, 40 V. The EFS induced transient frequency-dependent contractons, followed by a slowly recovering relaxation ewpecially at higher frequency of the EFS. In the presence of atropine and guanethidine, the contractions were virtually abolished, while the frequency-dependent relaxations by the EFS remained unaffected. The magnitude of relaxations progressively decreased as the location of the strips gets closer to the bottom of the gastric body. The relaxations were ablished by tetrodotoxin, indicating that their orgin is the NANC nerve stimulation. NG-nitro-L-arginine (L-NNA, 10-$100{\mu}M$), the inhibitor of nitric oxide (NO)-synthase, caused a concentration-dependent inhibition of the NANC relaxations. The inhibitory effects of L-NNA were not affected gy the location of the strips and were reversed by L-arginine, the precursor of NO-biosynthesis. Hemoglobin (20-$60{\mu}M$), a NO scavenger, inhibited the NANC relaxation s in a concentration-dependent manner. This inhibition was more prominent in the NANC relaxations observed in the lower portion of the gastric body and the relaxations induced ly lower frequencies of the EFS. Methyelne blue (10-$100{\mu}M$), an inhibitor of cytosolic guanylate cyclase, markedly inhibited the NANC relaxations, almost abolishing the response at a higher dose ($100{\mu}M$). These results suggest that NANX innervation of the rabbit gastric body progeressively decrease as he location of the strips gets closer to the bottom of the gastric body, and that the NANC relaxation is primarily mediated by NO-guanosine 3',5'-cyclic monophophate (cyclic GMP).