• Journal of Microbiology and Biotechnology
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• 제16권8호
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• pp.1285-1291
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• 2006

The proline utilization (put) operon of Vibrio vulnificus consists of the putAP genes encoding a proline dehydrogenase and proline permease. The result of put-lux transcriptional fusion analysis suggests that the V vulnificus putAP operon is not autoregulated by the PutA protein. A putR null mutation decreased proline dehydrogenase activity and the level of the put transcripts, indicating that transcription of putAP is under the positive control of PutR. The deduced amino acid sequence of the putR was similar to those reported from other bacteria with high levels of identity. Chromatin IP and GST pull-down assays revealed that PutR specifically binds to the putAP promoter region in vivo, and interacts with CRP in vitro. Taken together, the results suggested that PutR exerts its effect on putAP expression by directly interacting with CRP bound to the upstream region of P$_{put}$.

• BMB Reports
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• 제42권1호
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• pp.28-34
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• 2009

To understand the molecular mechanism underlying proline accumulation in Brassica napus, cDNAs encoding ${\Delta}^1$-pyrroline-5-carboxylate synthetase (BnP5CS), ornithine $\delta$-aminotransferase (BnOAT) and proline dehydrogenase (BnPDH) were isolated and characterized. Southern blot analysis of BnP5CSs in B. napus and its diploid ancestors suggested a gene loss may have occurred during evolution. The expression of BnP5CS1 and BnP5CS2 was induced, while the expression of BnPDH was inhibited under salt stress, ABA treatment and dehydration, prior to proline accumulation. The upregulation of BnOAT expression was only detected during prolonged severe osmotic stress. Our results indicate that stress-induced proline accumulation in B. napus results from the reciprocal action of activated biosynthesis and inhibited proline degradation. Whether the ornithine pathway is activated depends on the severity of stress. During development, proline content was high in reproductive organs and was accompanied by markedly high expression of BnP5CS and BnPDH, suggesting possible roles of proline during flower development.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2002년도 추계학술대회
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• pp.220.2-220.2
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• 2002

• Journal of Microbiology and Biotechnology
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• 제12권2호
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• pp.318-326
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• 2002

The pathogenic marine bacterium Vibrio vulnificus is the causative agent of food-borne diseases such as life-threatening septicemia. To better understand this organism's strategies to survive osmotic stress, a mutant that was more sensitive to high osmolarity was screened from a library of mutants constructed by a random transposon mutagenesis. By a transposon-tagging method, putAP genes encoding a proline dehydrogenase and a proline permease were identified and cloned from V. vulnificus. The amino acid sequences deduced from nucleotide sequences of putAP from V. vulnificus were 38 to $59\%$ similar to those of PutA and PutP reported from other Enterobacteriaceae. Functions of putAP genes were assessed by the construction of mutants, whose putAP genes were inactivated by allelic exchanges. When proline as the sole carbon or nitrogen source was used, the putA mutant was not able to grow to the substantial level, revealing the proline dehydrogenase is the only enzyme for metabolic conversion of proline into other amino acids. Although the growth rate of the putP mutant on proline as the sole carbon or nitrogen source was significantly reduced, the mutant still grew. This indicated that at least one more proline permease is produced by V. vulnificus. The putP mutant decreased approximately $2-log_10$ CFU/ml after a hyperosmotic challenge, while the parent strain decreased approximately $l-log_10$ CFU/ml. This result suggests that the gene product of putP contributes to the osmotic tolerance of V. vulnificus.

• 한국자원식물학회지
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• 제18권1호
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• pp.15-21
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• 2005

염류내성 식물은 염류농도의 변화에 따라 세포내의 삼투압을 유지하기 위한 화합물을 합성하는 기작을 가지고 있는데 이런 화합물은 주로 proline, glycine, betaine, polyols, sugar등으로 체내에 축적함으로서 고농도의 염류에 견디는 것으로 알려져 있다. Betaine은 미생물에서 2단계 반응을 통해 choline에서 합성되는데, 첫단계는 choline dehydrogenase (CDH)에 의해서 촉매되고(Bet A gene), bet B 유전자의 산물인 betaine aldehyde dehydrogenase(BADH)에 의해 수행된다. 본 실험에서는 Bet A, Bet B 유전자를 아그로박테리움에 도입하여 새로운 conjugants 2 종을 획득하였으며 (Agrobacterium tumefaciens MP90/pBet A, Agrobacterium tumefaciens MP90/pBet B), 먼저 재조합된 binary vector가 식물에서 발현 및 형질 전환되는지 여부를 조사하기 위해서 이미 담배에 형질전환을 시켰으며, 형질전환된 담배에서는 ,고농도의 kanamycin배지에서 생장이 가능하였고, PCR에 의하여 NPT II, Bet A, Bet B gene를 조사한 결과 담배 유식물체 모두 band가 형성되어 형질전환체임을 확인할 수 있었다. 인삼에 Beth, BetB gene의 도입은 1M의 mannitol이 함유된 식물호르몬 무첨가 MS 배지에서 단일배 발생방법에 형질전환체를 획득하였으나, 형질전환체의 발생빈도$(12\%)$가 매우 낮았다.

• Journal of Plant Biotechnology
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• 제5권3호
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• pp.173-179
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• 2003

The combination of a radiation technique with an in vitro culture system was appiled to develop submergence tolerant rice. The 3,000 $M_3$ lines with an average 80 percent of fertile grain were utilized for the selection of submergence tolerance. Salt tolerant lines were selected based on high plant height, root length and root number after submergence in plastic pots. Of the lines tested, the tolerant line (403-6) showed a dramatic difference in morphological traits under submergence compared to its original variety (Dongjinbyeo). It was suggested that genetic variations between the original variety and $M_3$-403-6 did exist. The levels of $\alpha$-amylase and alcohol dehydrogenase activities were significantly increased in the mutant line compared to its original variety. The mutant with greater tolerance showed less electrolyte leakage indicating a greater membrane integrity and better survival. Also, this line was much more resistant to a salt stress of $1.25\%$ than the original variety. The proline level of the line was significantly (p<0.01> higher than that of the original variety. The relationships between the inhibition of growth caused by stress and the physiological changes in the plant cell were discussed.

• 한국미생물·생명공학회지
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• 제14권5호
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• pp.427-432
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• 1986

The regulation of three ammonia assimilatory enzymes, GDH (glutamate dehydrogenase), GS (glutamine synthetase) and GOGAT (glutamate synthase), has been examined in C. glutamicum. Three kinds of arginine auxotrophs blocked in each step of arginine biosynthetic pathway from glutamate were selected as arg 5, arg 6, arg 8. Histidine and tryptophan auxotrophs were also selected because histidine and tryptophan repressed GS biosynthesis in E. coli. These strains were cultured on the media containing nitrogen-excess and limited conditions, to compare the specific activities of ${\alpha}$-ketoglutarate dehydrogenase(${\alpha}-KGDH$), GDH, GS, GOGAT from the cell-free extracts. These results showed that enzyme levels of ${\alpha}-KGDH$ and GDH from 3 kinds of arginine auxotrophs, histidine and tryptophan auxotrophs in nitrogen-excess condition and those of GS and GOGAT in nitrogen limited condition were increased compared with opposite condition. The tryptophan and histidine auxotrophs showed higher level of glutamate and glutamine than parental strains and other mutants. it is assumed that the higher levels of ${\alpha-KGDH}$ and GDH from mutants in nitrogen-excess condition promoted the accumulation of glutamate and glutamine in fermentation broth. The inhibition of GS activities by ADP suggested that GS is regulated by energy charge in C. glutamicum. The results with histidine, tryptophan, glycine, alanine, serine and GMP implied that a system of feedback inhibition were effective. The GDH, GS and GOGAT biosynthesis in culture broth was markedly repressed by the nature and kinds of available nitrogen sources such as tryptophan, proline, glycine, alanine, serine and tyrosine.

• 한국식품영양학회지
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• 제26권2호
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• pp.258-265
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• 2013

Home-made soy sauces with or without Hovenia dulcis Thunb (Hutgae) originated from different parts such as fruits, stems, and twigs were prepared according to the Korean traditional procedure. Soy sauces supplemented with Hutgae were evaluated for their activities of 2,2-diphenyl-1-picrylhydrazyl radical scavenging (DPPH) and alcohol dehydrogenase (ADH), free amino acid profiles, and sensory quality. All soy sauce types containing Hutgae had a strong DPPH activity as compared to the general type of soy sauce without Hutgae (GSC). Among Hutgae groups, DPPH activities of soy sauce supplemented with Hutgae stems was higher than that of soy sauces with either Hutgae fruits or twigs. ADH activities of soy sauces with Hutgae ranged from 14% to 55%, thus indicating that the functional activity of Hutgae was not altered during soy sauce preparations. Total free amino acid content of GSC was 295.5 mg%, and that of soy sauce with Hutgae fruits (346.8 mg%) was the highest when compared to Hutgae stems (272.3 mg%) and Hutgae twigs (225.6 mg%). In amino acid profiles, aspartate, arginine, histidine, and lysine levels were higher in soy sauces with Hutgae compared to GSC, whereas isoleucine, leucine, and phenylalanine levels were lower. Particularly, high levels of aspartate, glutamate, threonine, and lysine were presented in Hutgae twigs, whereas for Hutgae fruits and Hutgae stems, the levels of serine, glycine and arginine, and proline and methionine were high, respectively. According to sensory evaluations, Hutgae stems were preferred than GSC, due to the lower offensive smell and higher umami tastes. These findings demonstrate that soy sauce with Hutgae stems has potential protective effects against hangovers, improves the taste, and implies a possible functional ingredient.

• 한국식품영양과학회지
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• 제45권6호
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• pp.828-834
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• 2016

경남 합천 일대에서 재배된 보리수나무(Elaeagnus umbellata Thunb.)의 생리활성을 부위별(열매, 잎, 줄기)로 평가한 결과는 다음과 같다. 항산화 특성을 측정한 결과, 총폴리페놀 함량이 높게 나타난 줄기(829.6 mg/g) 에탄올 추출물에서 DPPH 라디칼 소거능($EC_{50}=54.04{\mu}g/mL$)이 가장 우수하였다. 유리 아미노산 분석에서는 잎(6,179.12 mg/100 g) 에탄올 추출물이 열매(378.88 mg/100 g)와 줄기(1,211.69 mg/100 g) 에탄올 추출물보다 유리 아미노산 함량이 높았으며, 열매의 proline, 잎의 asparagine 및 줄기의 GABA가 대표적인 유리 아미노산인 것을 확인하였다. LC-MS/MS를 이용한 주요 페놀 성분 분석에서는 잎 에탄올 추출물에서 gallic acid, 줄기 에탄올 추출물에서 catechin의 함량이 가장 높았으며, HepG2 cell과 Chang cell의 암세포 증식억제 효과를 측정한 결과 잎 에탄올 추출물이 HepG2에 특이적으로 높은 억제 활성이 나타났다. 향후 보리수나무를 국내 우수 자원으로 활용하기 위해서는 추가로 다양한 암세포에 대한 활성 차이, 부위별 활성 물질의 구명 및 작용 기전 등에 대한 계속된 연구가 수행되어야 할 것이다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권3호
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• pp.1635-1642
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• 2013

Helicobacter pylori antigen was prepared from an isolate from a patient with a duodenal ulcer. Serum samples were obtained from culture-positive H. pylori infected patients with duodenal ulcers, gastric ulcers and gastritis (n=30). As controls, three kinds of sera without detectable H. pylori IgG antibodies were used: 30 from healthy individuals without history of gastric disorders, 30 from patients who were seen in the endoscopy clinic but were H. pylori culture negative and 30 from people with other diseases. OFF-GEL electrophoresis, SDS-PAGE and Western blots of individual serum samples were used to identify protein bands with good sensitivity and specificity when probed with the above sera and HRP-conjugated anti-human IgG. Four H. pylori protein bands showed good (${\geq}$ 70%) sensitivity and high specificity (98-100%) towards anti-Helicobacter IgG antibody in culture-positive patients sera and control sera, respectively. The identities of the antigenic proteins were elucidated by mass spectrometry. The relative molecular weights and the identities of the proteins, based on MALDI TOF/TOF, were as follows: CagI (25 kDa), urease G accessory protein (25 kDa), UreB (63 kDa) and proline/pyrroline-5-carboxylate dehydrogenase (118 KDa). These identified proteins, singly and/or in combinations, may be useful for diagnosis of H. pylori infection in patients.