• Tuberculosis and Respiratory Diseases
• /
• 제53권2호
• /
• pp.161-172
• /
• 2002

연구배경 : 저자들은 기관지 내시경 검사상 관찰된 탄분 섬유화증(Anthracofibrosis, 이하 AF)과 결핵과의 연관성을 기관지 내시경 검체 결핵 PCR을 이용하여 알아보고자 하였고, 또한 결핵 PCR이 AF에 동반된 활동성 폐결핵의 신속한 진단에 도움이 되는지를 알아보고자 하였다. 방 법 : 기관지 내시경 검사상 기관지 협착이나 폐쇄를 동반한 기관지 점막의 탄분 침착을 갖는 25명의 여성과 5명의 남자를 포함한 총 30명의 환자를 대상으로 하였다. 기관지 세척액과 AF부위 조직을 대상으로 Mycobacterium tuberculosis의 IS6110분절을 대상으로 하는 PCR을 시행하였고, 또한 환자의 세균학적 검사 결과, 임상상, 및 임상경과를 분석하고 비교하였다. 결 과 : 임상분석상 18명(60%)이 결핵과 연관되어 있었고, 이 중 9명은 과거에 결핵을 앓은 병력이 있었으며 나머지 9명은 세균학적 검사상 활동성 결핵으로 판명되었다. 객담과 기관지 세척액에서 항산균 도말은 4명에서 양성 소견을 보였고, 항산균 배양양성은 9명 (30%)이었으며 AF의 조직검사 상 결핵을 보인 경우는 모두 5명이었다. 기관지 세척액과 AF조직에서의 TB-PCR은 각각 11명(37%), 5명(17%)에서 양성 소견을 보였다. PCR방법은 항산균 도말보다 폐결핵 진단에 민감하였으며 (민감도 89% vs 22%, respectively, p<0.05) AF조직에서 결핵으로 진단된 5명의 환자 모두 AF조직 및 기관지 세척액에서 TB-PCR 양성소견을 보였다. TB-PCR 양성이면서 조직학적 또는 세균학적으로 결핵의 증거를 보이지 않았던 3명의 환자 중 2명은 임상적으로 활동성 결핵이 의심되었고 나머지 한명은 과거에 결핵을 앓은 적이 있었던 환자이었다. 결 론 : 세균학적 및 조직학적 결핵 진단법과 비교하여 TB-PCR 방법이 추가로 AF와 결핵과의 연관성을 밝혀내지는 못하였으나, 기관지 세척액 TB-PCR은 AF와 동반된 활동성 폐결핵의 신속한 진단에는 도움이 될 것으로 기대된다. 조직학적 검사상 결핵의 증거가 없이 AF소견만 보인 모든 조직에서 결핵 PCR음성을 보인 점은 AF 병변 자체가 결핵의 감염 부위이거나 활동성 결핵 자체이기 보다는 결핵에 의한 이차적인 변화일 가능성이 높을 것으로 생각된다.

• 한국미생물생명공학회:학술대회논문집
• /
• 한국미생물생명공학회 1986년도 추계학술대회
• /
• pp.505.1-505
• /
• 1986

The gene for iso-1-cytochrome c for Saccharomyces cerevisiae was recloned into a pSP65 vector containing an active bacteriophage SP6 promoter. The iso-1-cytochrome c gene was cloned as an 856 bp Xho 1-Hind III fragment. When the resulting plasmid was digested at the Hind 111 site 279 bases downstream from the termination codon of the gene and transcribed in vitro using SP6 RNA polymerase, full length transcripts were produced. The SP6 iso-1-cytochrome c mRNA was translated using a rabbit reticulocyte lysate system and the protein products analyzed on SDS polyacrylamide gels. One major band was detected by autofluorography. This band was found to have a molecular weight of 12,000 Da and coincided with the Coomassie staining band of apocytochrome c from S. cerebisiae. The product was also shown to be identical with that of standard yeast apocytochrome c on an isoelectric focusing gel. The in vitro synthesized iso-a-cytochrome c was methylated by adding partially purified S-adenosyl-L-methionine . protein-lysine N-methyltransferase (Protein methylase III; EC 2.1.1.43) from S. cerevisiae along with S-adenosyl-L-methionine to the in vitro translation mixtures. The methylation was shown to be inhibited by the addition of the methylase inhibitor S-adenosyl-L-homocysteine or the protein synthesis inhibitor pu omycin. The methyl derivatives in the protein were identified as $\varepsilon$-N-mono, di and trimethyllysine by amino acid analysis. The molar ratio of methyl groups incorporated to that of cytochrome c molecules synthesized showed that 23% of the translated cytochrome c molecules were methylated by protein methylase III.

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권7호
• /
• pp.3047-3052
• /
• 2012

The enzyme encoded by the MGMT gene is involved in the repair of alkylated lesions formed in DNA by carcinogenic nitrosamines. Since dietary items consumed by the Kashmiri population contain high concentrations of these agents, it is biologically plausible that MGMT polymorphic variants may be associated with their risk of esophageal cancer. The present study was performed to assess whether non-synonymous SNPS at codon Leu84Phe and codon Ileu143Val of the MGMT gene, close to the active site of the protein, might be linked to predisposition of Kashmiris to esophageal cancer. Genotyping was carried out by polymerase chain reaction-restriction fragment length polymorphism on 92 cases and 77 healthy controls. Codon 84 and codon 143 SNPs of the MGMT gene were not associated with any increase in risk. While the frequency of the Phe allele at codon 84 in cases was (0.16), slightly higher than controls (0.12), the difference was not statistically significant. Similarly, the frequency of Valine allele in cases at codon 143 (0.08) and controls (0.09) was nearly equal. Moreover, no significant association of MGMT genotypes with the clinicopatholgic variables of esophageal cancer patients was observed. In conclusion, MGMT variants at codon 84 and codon143 may not be involved in the susceptibility of the Kashmiri population to esophageal cancer.

• Journal of Microbiology and Biotechnology
• /
• 제24권7호
• /
• pp.898-904
• /
• 2014

The stability of Bacillus licheniformis alpha-amylase (BLA) under acid condition was enhanced through direct evolution using the error-prone polymerase chain reaction. One beneficial mutation site, H281I, was obtained in BLA. The specific activity of H281I was 161/352 U/mg, which was 62.6/27.5% higher than that of the wild-type (WT) (99/276 U/mg) at pH 4.5/6.5 and $95^{\circ}C$. The pH optimum for H281I was decreased about 1 unit, whereas no significant changes of optimum temperature and thermostability were observed compared with the wild type (WT). The $k_{cat}/K_m$ value of H281I was 1.7-/1.4-fold higher at pH 4.5/6.5, respectively, than that of WT. The structure model analysis indicated that the H281I mutation altered the predicted interaction between the amino acid residues at 281 and 273, thus creating a conducive local environment for substrate binding, as reflected by its decreased $K_m$, and consequently increased the specific activity.

• 환경생물
• /
• 제20권3호
• /
• pp.224-231
• /
• 2002

광주기(하루 중 빛의 길이)는 골든 햄스터의 생식을 조절하는 주된 요인이다. 광주기 정보는 멜라토닌을 통하여 생식 내분비계로 전달된다. 따라서 멜라토닌이 생식에 미치는 효과를 여러 광주기에 노출시킨 햄스터에서 조사하였다. 단주기(하루 중 12시간 이하의 조명)에 노출시킨 동물들과 저녁에 멜라토닌을 주사한 동물들의 정소 무게는 현저하게 줄어들었으나, 장주기 (하루 중 12.5시간 이상의 조명)에 유지된 동물과 오전에 멜라토닌을 투여한 동물들의 정소 무게는 줄어들지 않았다. 퇴화된 정소를 조직학적으로 조사한 결과, 세정관 직경이 감소되었고, 세정관내 세포수가 두드러지게 줄어들었다. 또한 생식 능력이 퇴화된 동물의 혈중 여포자극호르몬과 황체호르몬의 수준도 생식 능력을 보유하고 있는 동물에 비해 뚜렷하게 감소하였다. 멜라토닌 수용체가 역전사 polymerase chain reaction으로 동정되었고 조직특이성 또한 조사하였다. 동정된 멜라토닌 수용체는 309염기였으며, 시상하부와 뇌하수체를 포함하는 다양한 장기에서 발현되었다. 생식을 조절하는 핵심 물질인 gonadotropin releasing hormone (GnRH) 유전자의 발현 또한 동정되었다. 그러나 멜라토닌 처리와 광주기 처리는 GnRH유전자 발현에 영향을 미치지 않았다. 종합하면, 광주기의 효과는 멜리토닌을 경유하여 발휘되며, 멜라토닌은 GnRH유전자의 발현보다는, 생성된 GnRH의 분비에 영향을 미쳐 생식내분비계에 간접적으로 작용함을 알 수 있었다.

• 식물조직배양학회지
• /
• 제24권1호
• /
• pp.1-35
• /
• 1997

Fertilized egg, by successive cell divisions, differentiates into different tissues and organs with various structures and functions. Different cells and tissues contain different proteins, products of selective gene expression. Not all the genes in any genomes are equally active, temporal and spatial gene expression being the general rule. Present paper attempts to review the tanscriptional mechanisms or the initiations of transcription from several angles. In some of the organisms the genes in the process of transcription or the genes in the inactive state can be seen under the light microscope. Some bands of Drosophila polytene chromosomes may exhibit a swollen or puff appearance under certain conditions. A puff, unfolded or decondensed form of chromomere, represents sets of intense transcriptional activity or RNA synthesis. The heterochromatic X chromosome whose genes remain inactive in the female mammals can be visualized as a dark staining structure called Barr body, Configuration of chromatin differs between transcribed and nontranscribed chromatin. Modification to the chromatin facilitates RNA synthesis. The movement of large polymerase molecule along the DNA would probably be facilitated if some modifications of the chromatin configuration is effected. Methylation of cytosines in CG sequences is associated with inactive genes. Methylation can play a role in determination of mammalian cells during embryogenesis. Demethylation is necessary for the gene to be expressed during development A histone modification that is also known to be correlated with transcriptional capacity of chromatin is acetylation of the lysine residues of the core histones. Chromatin containing a high level of histone acetylation is very sensitive to DNase 1. For the transcription to occur TBP must first bind to the TATA box. Another TF, TF IIB, then binds to the promoter-TBP complex, facilitating the access of RNA polymerase to the transcription initiation site. As recently as eight years ago researchers assumed that histones were irrelevant to the regulation of gene expression. Histones combine with the DNA to form nucleosome of the chromatin. Histones are vital participant in gene regulation. Histone and basal factors compete for access to TATA box. When DNA is exposed to basal factors before histones are introduced, the basal factors assemble on TATA boxes preventing the access of histones, allowing transcription to occur, for transcription to begin, activator protein at the upstream activation sequence or enhancer must interact with the tail of histone H4 at TATA box and cause the histone role particle to dissociate from the TATA box leading to partial breakup of the histone core particle and allowing the basal factors to bind to the TATA box. New concept of genomic flux in contrast to the old concept of static genome has been developed based on the powerful new molecular techniques. Genomic changes such as repetitive DNAs and transposable elements, it is assumed but not yet proved, may affect some of the developmental patterns that characterize particular cells, tissues, organs, and organisms. In the last decade or so remarkable achievement have been made in the researches of the structures and functions of TFs and the specific target sequences located in promoters or enhancers where these TFs bind. TFs have independent domains that bind DNA and that activate transcription. DNA binding domain of TFs serves to bring the protein into the right location. There are many types of DNA binding domains. Common types of motifs can be found that are responsible for binding to DNA. The motifs are usually quite short and comprise only a small part of the protein structure. Steroid receptors have domains for hormone binding, DNA binding, and activating transcription. The zinc finger motif comprises a DNA binding domain. Leucine zipper consist of a stretch of amino acids with a leucine residue in every seventh position Two proteins form a dimer because they interact by means of leucine zippers on similar α-helical domain. This positions their DNA binding basic domains for interaction with the two halves of a DNA sequence with dyad symmetry of TGACTCA, ACTGAGT.