• 생명과학회지
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• 제21권3호
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• pp.368-374
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• 2011

식물의 저온 적응 메카니즘에서 아스코브산과 관련된 효소 중 MDHA 환원효소의 활성도와 과산화수소, 아스코브산의 함량, mRNA의 발현수준과의 연관성을 연구한 결과는 다음과 같다. MDHA 환원효소의 활성도 변화는 저온에 노출되는 시간이 길어질수록 증가하였으며 6시간 이후에 엽록체분획과 세포질분획에서 급격하게 증가하는 경향을 보였으나 실온으로 회복시켰을 때 효소의 활성도가 상대적으로 감소하는 경향을 보였다. 저온에 노출된 동안 아스코브산의 함량은 비교적 일정한 경향을 보이다가 실온으로 회복시키면 그 이후에는 급격하게 증가하는 경향을 보였다. 반면 저온에 노출되는 동안 급격히 dehydroascorbate 함량이 감소하였다가 실온으로 회복되면 약간 증가하는 경향을 보였다. 아스코브산의 함량과 엽록체분획과 세포질분획의 MDHA 환원효소의 활성도와의 상관관계는 각각 정의 상관($R^2$=0.9240, 0.9108)을 나타내었으나 디하이드로아스코브산의 함량과 MDHA 환원효소의 활성도 사이에는 각각 부의 상관($R^2$=0.8638, 0.8980)을 나타내었다. MDHA 환원효소 활성도와 과산화수소의 함량과의 상관관계를 과산화수소의 생성량이 증가하면 MDHA 환원효소의 활성도가 증가하는 정의 상관($R^2$=0.9443, 0.9647)을 나타내었다. 저온스트레스 처리 시간이 증가할수록 MDHA 환원효소의 mRNA의 발현 수준과 총 MDHA 환원효소의 활성도가 증가하는 경향을 나타내었다.

• Archives of Pharmacal Research
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• 제19권6호
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• pp.486-489
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• 1996

A simple, rapid, specific and sensitive method for the detection of serum hepatitis C virus (HCV) RNA using the reverse transcription-polymerase chain reaction (RT-PCR) technique without conventional RNA extraction was developed. HCV template RNA from serum was obtained by boiling the serum at $95^{\circ}C$ for 2 min, cooling rapidly in ice and removing the proteins by cetrifugation. RT-PCR amplifications including the reverse transcription and first PCR amplification were performed in one vessel containing both of reverse transcriptase and Taq DNA polymerase. The detection of HCV RNA from $10^{-3}{\mu}l$. serum was possible with this method. The suitability of this method for clinical analysis was evaluated by assaying HCV RNA in 225 patient samples including anti-HCV antibody negatives (13 samples) and positives (212 samples) by enzyme-linked immunosorbent assay test (ELISA). Detections of HCV RNA with this method were in 4 of 13 anti-HCV antibody negative samples (30.8%) and 95 of 212 positive samples (44.8%). The present method can be completed in 1 hr and has a wide range of application for the clinical utilities to determine the viral RNAS.

• Food Science and Biotechnology
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• 제17권4호
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• pp.892-894
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• 2008

During dongchimi fermentation at 5 and $25^{\circ}C$, the pH lowered slowly and reached 4.03 at $5^{\circ}C$ after 30 days, whereas it lowered dramatically and reached 3.59 at $25^{\circ}C$ after 2 days. The predominant bacteria were Leuconostoc (Leu.) mesenteroides at $25^{\circ}C$ until day 2 which changed into Lactobacillus (Lb.) plantarum at day 3, analyzed by a culture dependent method with partial 16S rRNA gene sequencing, whereas Leu. mesenteroides occupied predominantly at $5^{\circ}C$ until day 7. In a culture-independent method using a polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) with partial 16S rRNA gene sequencing, Lb. algidus was predominant at $5^{\circ}C$ until day 7 and Lb. plantarum occupied predominantly at $25^{\circ}C$ until day 3, which is different from the results of the culture based method, indicating the both methods need to be combined for accuracy. Based on the culture-dependent method, Leu. mesenteroides might be responsible for the early and mid-phase of dongchimi fermentation.

• 대한수의학회지
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• 제38권3호
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• pp.565-573
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• 1998

To study the specific tools for the diagnosis of Newcastle disease virus (NDV) in chicken, polymerase chain reaction (PCR) and its presumable conditions were evaluated for the detection of hemagglutinin-neuraminidase (HN) gene of NDV RNA. For these purposes, Kyojeongwon strain of the NDV was propagated in allantoic cavity of SPF embryonating chicken eggs, and viral RNA was extracted from fractionated virus after the allantoic fluids were ultracentrifuged with sucrose gradient. The first-strand cDNA was then made for the HN gene of NDV RNA by reverse transcription at $42^{\circ}C$ for 1 hour using specific primer complementary to the HN gene. The single-stranded cDNA was used as template in the PCR of the HN-DNA, and various conditions of the PCR were evaluated to set up method for the specific detection of the HN-DNA. The PCR conditions promising for the detection of HN gene consist of preheating at $94^{\circ}C$, 5 min, 30 cycles of denaturation at $94^{\circ}C$, 1 min, annealing at $55^{\circ}C$, 1 min and polymerization at $72^{\circ}C$, 2 min, and a cycle of extension at $72^{\circ}C$, 5 min. when NDVs of allantoic fluids without fractionation were applied to the above PCR condition, the HN genes were detected effectively not only from Kyojeongwon but from other velogenic strains such as Herts and a field isolate.

• 미생물학회지
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• 제21권3호
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• pp.163-169
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• 1983

Effects of temperature on the gorwth characteristics and the chemical composition of pseudomonas cells grown under glucose-or methanol-utilizing continuous culture were studied. In a glucose-utilizing continuous culture, optimum dilution rate, agitation, pH, and temperature, for the higher biomass yield were $0.45hr^-$, 7000rpm, pH 7.5, and $30^{\circ}C$, respectively. But in a methanol-utilizing continuous culture, they were $0.125hr^-$, 600rpm, pH 8, and $30^{\circ}C$, respectively. In methanol-utilizing continuous culture, the maximum production rate of the cells was 1.48g, dry wt./1/hr at a dilution rate of $0.45hr^-$, and the cell yield was 0.46g. dry wt./g. glucose. In the methanol-utilizaing continuous culture, the maximum production rate of the cells was 0.33 7g. dry wt./1/hr. at a dilution rate of $0.125hr^-$ and the cell yield was 0.44g dry cell/g. methanol. The contents of protein of the cells increase with the increase ingrowing temperature (from 15 to $30^{\circ}C$), more or less, while the contents of RNA nad carbohydrate of the cells decreased. However, DNA contents of cells growth under the various temperature ranges didn't change. As the temeprature of cultivation rises at a constant dilution rate, the efficiency of RNA in protein synthesis was increased, showing the decreases in the ratio of RNA to protein.

• Clinical and Experimental Pediatrics
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• 제53권2호
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• pp.178-183
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• 2010

목 적 : 최근에 macrolide계 항균제에 내성인 M. pneumoniae 균주가 증가한다는 외국의 보고가 있었으며, 국내에서 수행된 한 연구에서도 M. pneumoniae의 macrolide 내성률을 49% 정도로 보고한 바 있다. 이에, 본 연구는 M. pneumoniae 폐렴으로 진단된 소아의 비인두 흡인물에서 M. pneumoniae의 macrolide 계항균제 내성에 연관된 것으로 알려진 유전자 변이 유무를 확인하고, M. pneumoniae의 macrolide계 항균제에 대한 최소억제농도를 측정하기 위한 기초 연구로 M. pneumoniae 배양법을 구축하고자 시행되었다. 방 법 : 2000년과 2003년 M. pneumoniae 감염의 유행기에 급성 호흡기 증상을 주소로 서울대학교 어린이병원과 분당서울대학교병원에서 치료받은 소아 중 혈청학적 검사와 M. pneumoniae PCR을 통해 M. pneumoniae 폐렴으로 진단받은 환아 62명으로 부터 채취하여 $-80^{\circ}C$에 보관되었던 비인두 흡인물을 대상으로 하였다. M. pneumoniae의 23S rRNA domain V의 peptidyl transferase 부위와 ribosomal protein L4를 M. pneumoniae 특이 PCR로 증폭한 후 염기서열분석을 시행하였다. 염기서열의 분석은 M. pneumoniae 표준 균주와 비교하여, 23S rRNA domain V의 A2063G, A2064G 변이와 ribosomal protein L4의 M144V변이 유무를 확인하였다. 또한, M. pneumoniae 표준 균주와 33개의 비인두흡인물($-80^{\circ}C$에 보관되었던 28검체와 1-2일간 냉장보관되었던 비인두흡인물 5 검체)을 Chanock's glucose 액체배지와 한천배지에 접종하고 $37^{\circ}C$의 5% $CO_2$ 항온기에서 6주간 관찰하여 배양을 확인하였다. 결 과 : 총 62 검체 중 23S rRNA gene에 대한 염기서열분석이 가능했던 61 검체 중 1검체(1.6%)에서 A2064G변이가 관찰되었고, 62 검체의 ribosomal protein L4에 대한 염기서열분석 결과 17검체(27.4%)에서 M144V 아미노산 변이가 확인되었다. M. pneumoniae 배양 결과, 표준 균주는 Chanock's glucose 액체배지와 한천배지 모두에서 배양되었고 2009년에 채취된 5검체 중 2검체에서 배양이 확인되었으나, $-80^{\circ}C$에 보관되었던 28검체는 모두 배양되지 않았다. 결 론 : 본 연구에서 23S rRNA gene의 유전자 변이 빈도는 매우 낮았고, ribosomal protein L4의 M144V 변이는 좀 더 많은 검체에서 확인되었다. Macrolide계 항균제에 내성인 M. pneumoniae의 분포와 M. pneumoniae의 23S rRNA gene과 ribosomal protein L4의 변이에 대한 추가적인 연구들을 통해 M. pneumoniae의 macrolide 항균제에 대한 내성기전을 이해하는데 도움을 줄 수 있을 것으로 생각된다.

• Applied Biological Chemistry
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• 제37권6호
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• pp.447-450
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• 1994

RNA의 가수분해시에 생성되는 cyclic phosphate 중간체의 모델 화합물인 ethylene phosphate의 P-O결합 분해속도 상수는 $100^{\circ}C$ 에서 $k=3{\times}10^{-7}s^{-1}({\Delta}H{\neq}=24\;kcal,\;{\Delta}S{\neq}=25.5\;eu)$이었으며 DNA모델 화합물인 dimethylphosphate는 $150^{\circ}C$에서 $1{\times}10^{-11}s^{-1}({\Delta}H{\neq}=36\;kcal,\;{\Delta}S{\neq}=25.5\;eu)$이었다. RNA모델 화합물인 hydroxyethylmethylphosphate의 가수분해는 dimethylphosphate의 C-O결합이 가수분해되는 반응속도와 비교될 만한 정도의 반응속도가 관측되었다.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 1986년도 추계학술대회
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• pp.521.1-521
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• 1986

B. sphaericus의 sporeless ts-D1216 돌연변이체의 유전학적 특성을 방사성 동위원소를 이용하여 DNA의 합성과 RNA의 합성을 측정하였고 일반적 특성을 연구하였다. ts-D1216 돌연변이체의 대수증식기 세포를 3$0^{\circ}C$에서 제한온도 (42$^{\circ}C$)로 이동시켰을 때 RNA의 합성은 4-5시간 정상적으로 합성이 계속 일어났고, DNA의 합성은 60-100분까지는 정상적인 율로 일어나다가 그 후에 결정적으로 감소되었다. 또한, DNA합성이 멈춘후에도 세포수는 증가했고, 4$0^{\circ}C$에서 성장기간이 더 길면 길수록 DNA합성에의 회복능력이 상실되었다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권1호
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• pp.23-34
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• 2004

Escherichia coli transcription termination factor Rho catalyzes the unwinding of RNA/DNA duplex in reactions that are coupled to ATP binding and hydrolysis. Fluorescence stopped-flow methods using ATP and the fluorescent 2'(3')-O-( N-methylanthraniloyl) derivatives (mant-derivatives) of ATP and ADP were used to probe the kinetics of nucleotide binding to and dissociation from the Rho-RNA complex. Presteady state nucleotide binding kinetics provides evidence for the presence of negative cooperativity in nucleotide binding among the multiple nucleotide binding sites on Rho hexamer. The binding of the first nucleotide to the Rho-RNA complex occurs at a bimolecular rate of 3.6${\times}$10$\^$6/ M$\^$-1/ sec$\^$-1/ whereas the second nucleotide binds at a slower rate of 4.7${\times}$10$\^$5/ M$\^$-1/ sec$\^$-1/ at 18$^{\circ}C$, RNA complexed with Rho affects the kinetics of nucleotide interaction with the active sites through conformational changes to the Rho hexamer, allowing the incoming nucleotide to be more accessible to the sites. Adenine nucleotide binding and dissociation is more favorable when RNA is bound to Rho, whereas ATP binding and dissociation step in the absence of RNA occurs significantly slower, at a rate ∼70- and ∼40-fold slower than those observed with the Rho-RNA complex, respectively.

• BMB Reports
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• 제29권5호
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• pp.393-397
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• 1996

Sprague-Dawley male rats (150 g) were chronically treated with 5 v/v % ethanol admixed with nutritionally complete liquid diet and fed ad libitum for 3 weeks. Controls were pair fed with the isocaloric sucrose liquid diet. One half of each group was exposed to cold stress at $4^{\circ}C$ either for 24 h (for determination of mRNA by in situ hybridization) or for 48 h (for determination of enzyme activity). Chronic ethanol treatment (ethanol) did not affect tyrosine hydroxylase (TH) mRNA level in locus coeruleus (LC) of brain and adrenal medulla (AM) compared to controls. Cold stress showed strong increase of TH mRNA level in LC and AM compared to controls. Pretreated ethanol reduced the increased TH mRNA level by cold stress in LC and AM. Ethanol did not affect TH activity in LC and adrenal glands (adrenals). Cold stress increased TH activity in LC but not in adrenals. Pretreated ethanol did not reduce the increased TH activity by cold stress in LC but this result was not shown in adrenals. It is suggested that ethanol does not affect the message level and enzyme protein level for TH in LC and AM in normal rat. It is also hypothesized that pretreated ethanol reduces the magnitude of acute cold stress response, that is induction of TH mRNA in LC and AM, and does not reduce the increased TH enzyme protein that is also acute cold stress response in LC.