• Molecules and Cells
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• 제38권1호
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• pp.33-39
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• 2015

The correction of disease-causing mutations by single-strand oligonucleotide-templated DNA repair (ssOR) is an attractive approach to gene therapy, but major improvements in ssOR efficiency and consistency are needed. The mechanism of ssOR is poorly understood but may involve annealing of oligonucleotides to transiently exposed single-stranded regions in the target duplex. In bacteria and yeast it has been shown that ssOR is promoted by expression of $Red{\beta}$, a single-strand DNA annealing protein from bacteriophage lambda. Here we show that $Red{\beta}$ expression is well tolerated in a human cell line where it consistently promotes ssOR. By use of short interfering RNA, we also show that ssOR is stimulated by the transient depletion of the endogenous DNA mismatch repair protein MSH2. Furthermore, we find that the effects of $Red{\beta}$ expression and MSH2 depletion on ssOR can be combined with a degree of cooperativity. These results suggest that oligonucleotide annealing and mismatch recognition are distinct but interdependent events in ssOR that can be usefully modulated in gene correction strategies.

• Journal of Applied Biological Chemistry
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• 제44권4호
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• pp.163-166
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• 2001

Piezoelectric (PZ) crystal biosensor system was used to detect the DNA of food pathogenic Listeria monocytogenes. L. monocytogenes-specific DNA was multiplied via the polymerase chain reaction using LM1 oligonucleotide (5'-TTACGAATTAAAAAGGAGCG-3') and LM2 oligonucleotide (5'-TTAAATCAGCAGGGGTCTTT-3') as primers. DNA fragment of 161 bp, which was specific only for L. monocytogenes, was observed. To obtain a large amount of single-stranded DNA containing an SH group used for coupling to the gold electrode chemisorptively, LM1 oligonucleotide containing a mercaptohexyl group was utilized as a single strand PCR primer. The PCR product was immobilized onto the gold electrode of PZ crystal, and hybridization was monitored in quartz crystal microbalance (QCM) system by injecting the antisense single-stranded DNA of 161 nucleotides obtained via the single strand PCR using the unmodified LM2 primer. Approximately 70 Hz of frequency drop was observed in the QCM system in the case of two consecutive injections of $5{\mu}g$ of the antisense single-stranded DNA.

• Bulletin of the Korean Chemical Society
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• 제31권7호
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• pp.2011-2014
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• 2010

The fluorescence intensity of a single-stranded oligonucleotide containing a fluorene-labeled deoxyuridine $(U^{Fl})$ unit increases by only 1.5-fold upon formation of its perfectly matched duplex. To increase the fluorescence signal during hybridization, we positioned a quencher strand containing a deoxyguanine (dG) nucleobase, functioning as an internal quencher, opposite to the $U^{Fl}$ unit to reduce the intrinsic fluorescence upon hybridization with a probe. From an investigation of the optimal length of the quencher strand and the effect of the neighboring base sequence, we found that a short strand (five-nucleotide) containing all natural nucleotides and dG as an internal quencher was effective at reducing the intrinsic fluorescence of a linear beacon; it also exhibited high total discrimination factors for the formation of perfectly matched and single base-mismatched duplexes. Such assays that function based on clear changes in fluorescence in response to single-base nucleotide mutations would be useful tools for accelerating diagnoses related to various diseases.

• BMB Reports
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• 제32권6호
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• pp.529-534
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• 1999

Asymmetric PCR and single-strand conformation polymorphism (SSCP) methods were combined to analyze human leukocyte antigen (HLA)-DRB allele polymorphism. Asymmetric PCR amplification was applied to generate single-stranded DNA (ssDNA) using the nonradioactive oligonucleotide primers desinged for the polymorphic exon 2 region. The conformational differences of ssDNAs, depending on the allele type, were analyzed by nondenaturing polyacrylamide gel electrophoresis and visualized by ethidium bromide staining. The ssDNAs were clearly separated from double-stranded DNA without interference and obviously migrated depending on their allele type. This method was applied to the genomic DNA either from homozygous or from heterozygous cell lines containing the DR4 allele as template DNA using DR4-specific primers, and satisfying results were obtained. Compared to the standard PCR-SSCP method, this asymmetric PCR-SSCP method has advantages of increased speed, reproducibility, and convenience. Along with PCR-SSP or sequence-based typing, this method will be useful in routine typing of HLA-DRB allele.

• Biotechnology and Bioprocess Engineering:BBE
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• 제7권4호
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• pp.212-215
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• 2002

Tyrosinase transcript In the blood Is known as the marker of malignant melanoma and it has been often determined by using reverse transcription-polymerase chain reaction (RT-PCA) . However, after the PCR process, the quantification of amplified CDMA by the gel electrophoresis is not reliable and time-consuming. for this reason, we tried to quantify the PCR product using a cuvette-type biosensor, where the oligonucleotide probe was immobilized on the cuvette surface and the single strand CDMA, the denatured PCH product, was then hybridized onto the immobilized probe to give a response signal. The response was Immediate and takes 15 min to obtain a stable signal. The biosensor was much more sensitive comparing to the gel electrophoresis method. The quantification of PCR product using a cuvette-type biosensor was feasible and rapid.

• 한국미생물·생명공학회지
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• 제45권4호
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• pp.358-364
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• 2017

Asymmetric PCR preferentially amplifies one DNA strand for use in DNA hybridization studies. Linear-After-The-Exponential-PCR (LATE-PCR) is an advanced asymmetric PCR method which uses innovatively designed primers at different concentrations. This study aimed to optimise LATE-PCR parameters to produce single-stranded DNA of Candida spp. and Aspergillus spp. for detection via probe hybridisation. The internal transcribed spacer (ITS) region was used to design limiting primer and excess primer for LATE-PCR. Primer annealing and melting temperature, difference of melting temperature between limiting and excess primer and concentration of primers were optimized. In order to confirm the presence of single-stranded DNA, the LATE-PCR product was hybridised with digoxigenin labeled complementary oligonucleotide probe specific for each fungal genus and detected using anti-digoxigenin antibody by dot blotting. Important parameters that determine the production of single-stranded DNA in a LATE-PCR reaction are difference of melting temperature between the limiting and excess primer of at least $5^{\circ}C$ and primer concentration ratio of excess primer to limiting primer at 20:1. LATE-PCR products of Candida albicans, Candida parapsilosis, Candida tropicalis and Aspergillus terreus at up to 1:100 dilution and after 1 h hybridization time, successfully hybridised to respective oligonucleotide probes with no cross reactivity observed between each fungal genus probe and non-target products. For Aspergillus fumigatus, LATE-PCR products were detected at 1:10 dilution and after overnight hybridisation. These results indicate high detection sensitivity for single-stranded DNA produced by LATE-PCR. In conclusion, this advancement of PCR may be utilised to detect fungal pathogens which can aid the diagnosis of invasive fungal disease.

• Journal of Korean Neurosurgical Society
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• 제46권6호
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• pp.558-563
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• 2009

Objective : Moyamoya disease (MMD) is an uncommon cerebrovascular disorder, characterized by progressive occlusion at the terminal portion of the internal carotid artery. Incidence of the disease is high in East Asia and familial MMD accounts for about 15% of the disease. Although the pathogenesis is unknown, association of HLA class I or II alleles with MMD has been reported with conflicting results. We investigated whether there is a difference in HLA class II association between familial and non-familial forms of the disease. Methods : A total of 70 Korean children with MMD, including 16 familial cases (10 probands), and 207 healthy controls were studied. Among familial cases, only 10 probands were used for the HLA frequency analysis. High resolution HLA-DRB1 and DQB1 genotyping was performed using polymerase chain reaction (PCR)-sequence specific oligonucleotide hybridization and PCR-single strand conformation polymorphism methods. Results : The phenotype frequencies of HLA-DRB1*1302 (70.0%) and DQB1*0609 (40.0%) were significantly increased in familial MMD compared to both controls [vs. 15.5%, corrected p ($p_c$) = 0.008, odds ratio (OR) = 12.76; vs. 4.3%, $p_c\;=\;0.02$, OR = 14.67] and non-familial MMD patients (vs. 14.8%, $p_c\;=\;0.02$, OR = 13.42; vs. 1.9%, $p_c\;=\;0.02$, OR = 35.33). The frequencies of DRB1 and DQB1 alleles in non-familial MMD patients were not significantly different from those in controls. Conclusion : Our findings suggest that the genetic polymorphism of HLA class II genes or other closely linked disease relevant gene(s) could be a genetic predisposing factor for familial MMD.

• Tuberculosis and Respiratory Diseases
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• 제54권4호
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• pp.367-377
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• 2003

연구배경 : 결핵균에 감염된 사람 중 약 10%만이 임상적으로 발병하는 것으로 보아 결핵의 발병 감수성에 숙주의 유전적 인자가 작용할 것으로 생각되고 있다. 저자들은 한국인 폐결핵 환자를 대상으로 고해상도 HLA 형별검사를 이용한 대립유전자 수준의 HLA-DR 및 DQ 유전자의 연관성에 대해 분석해 보았다. 방 법 : 이전 결핵 치료력이 없는 결핵 환자 67명(약제감수성군 38명, 다제내성군 29명)과 200명의 정상대조군을 대상으로 하였으며 HLA-DRB1 형별검사는 reverse SSO (sequence specific oligonucleotide)와 PCR-SSCP (single strand conformational polymorphism) 방법으로, DQB1 형별검사는 PCR-RFLP (restriction fragment length polymorphism), PCR-SSCP 및 PCR-SSP (sequence specific primer) 방법으로 시행하였다. 결 과 : 결핵환자군 중 다제내성군에서 대조군에 비해 DRB1*0701과 *08032의 빈도가 약 2배 정도 증가되는 경향을 보였고 이들 대립유전자와 연관된 DQB1*0202와 *0601(15.5% vs 34.5%, p=0.01)이 증가되었다. DQB1*0609는 결핵환자군에서 대조군에 비해 유의하게 증가되었고(4.0% vs 14.9%, p=0.004), 약제감수성군과 다제내성군에서 유사한 정도의 증가를 보였다. 폐병변의 중증도와 HLA의 연관성을 보면 덜 진행된 군(약제감수성군의 경증, 다제내성군의 중등증)에 비해 더 진행된 군(약제감수성군의 중등증+중증, 다제내성군의 중증)에서 DRB1*08032(4.2% vs 32.6%, p=0.007)와 DQB1*0601(12.5% vs 34.9%, p=0.047)이 유의하게 증가되었다. DQB1*0609는 다제내성군에서는 중증군에서, 약제감수성군에서는 경증군에서 대조군에 비해 유의하게 증가되었고 DRB1*0701과 DQB1*0202는 다제내성군의 중등증군에서만 유의하게 증가되어 이들 대립유전자는 폐병변의 중증도와 일정한 연관을 보이지는 않았다. 결 론 : HLA-DRB1*08032 및 DQB1*0601 대립유전자는 한국인에서 다제내성 결핵의 유전적 감수성인자로 생각되며 질환의 중증도와도 연관을 보이는 것으로 나타났다.