• 제목/요약/키워드: cytosine

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Structural Analysis of Cu Binding Site in [Cu(I)·d(CpG)·d(CpG)-2H]-1 Complex

  • Im, Yu-Jin;Jung, Sang-Mi;Kang, Ye-Song;Kim, Ho-Tae
    • Bulletin of the Korean Chemical Society
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    • 제34권4호
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    • pp.1232-1236
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    • 2013
  • The Cu cation binding sites of $[Cu(I){\cdot}d(CpG){\cdot}d(CpG)-2H]^{-1}$ complex have been investigated to explain the $[Cu{\cdot}DNA]$ biological activity caused by the Cu association to DNA. The structure of $[Cu(I){\cdot}d(CpG){\cdot}d(CpG)-2H]^{-1}$ complex was investigated by electrospray ionization mass spectrometry (ESI-MS). The fragmentation patterns of $[Cu(I){\cdot}d(CpG){\cdot}d(CpG)-2H]^{-1}$ complex were analyzed by MS/MS spectra. In the MS/MS spectra of $[Cu(I){\cdot}d(CpG){\cdot}d(CpG)-2H]^{-1}$ complex, three fragment ions were observed with the loss of d(CpG), {d(CpG) + Cyt}, and {d(CpG) + Cyt + dR}. The Cu cation binds to d(CpG) mainly by substituting the $H^+$ of phosphate group. Simultaneously, the Cu cation prefers to bind to a guanine base rather than a cytosine base. Five possible geometries were considered in the attempt to optimize the $[Cu(I){\cdot}d(CpG){\cdot}d(CpG)-2H]^{-1}$ complex structure. The ab initio calculations were performed at B3LYP/6-31G(d) level.

Pseudomonas oleovorans의 pyrimidine nucleotide N-ribosidase의 생성 최적조건 (Optimization of Culture Conditions for the Production of Pyrimidine Nucleotide N-Ribosidase from Pseudomonas oleovorans)

  • Yu, Tae-Shick
    • 생명과학회지
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    • 제14권4호
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    • pp.608-613
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    • 2004
  • Pyrimidine nucleoade N-ribosidase (pyrimidine 5'-nucleotide phosphoribo (deoxyribo) hydrolase/ pyrimidine 5'-nucleotide nucleosidase, EC 3.2.2.10)는 CMP와 UMP를 직접 분해하여 cytosine과 uracil를 생성하는 가수분해효소이다. 본 연구에서는 Pseudomonas oleovorans ATCC 8062의 생육과 pyrimidine nu-cleotide N-ribosidase생성에 미치는 탄소원과 질소원의 영향 및 생육인자 등에 대하여 검토했다. 효소생성의 최적배양조건은 2% fumarate, 1.5% peptone, 5% corn steep liquor (CSL)과 1% ammonium chloride의 배지조성(초기 pH 7.0)으로 $28^{\circ}C$, 48시간 진탕 배양이 양호했다. 효소의 활성은 생육이 최대에 도달하는 정지기 후기에 최대에 도달하며, 그 이후부터 급속히 불활성화 되었다. P. oleovorans의 pyrimidine nucleocde N-ribosidase는 UMP에 의하여 유도 생성되지 않으므로 구성효소이며, 내생효소였다.

분홍색 통성 메탄올 자화세균의 분리 및 특성 (Isolation and Characterization of a Pink-Pigmented Facultative Methylotrophic Bacterium)

  • 양석훈;김영민
    • 미생물학회지
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    • 제27권1호
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    • pp.63-69
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    • 1989
  • 흙으로부터 에탄올을 이용하여 성장하는 분홍색 통성 에단올 자화세율을 분리하여 Methylobacteriu~η sp. strain SY 1이라 명명하였다. 이 세균은 그람음성세균으호 약간 굽은 간균이고 한쪽 끝에 달련 한개의 편모로 운동하였다. 세균의 군략은 매끈 하고 밝은 분홍맺을 띄우며 정성이 높았다. 이 세균이 지니는 DNA의 G+C 함량은 약 66%로 나타났다. 이 제균은 칠대호가 성으호 catalase와 oxidase 활성을 나타내었고, carotenoid 색소와 poly-$\beta$-hydroxy butyrate를 가지고 있었다. 이 세균은 또 한 세가지 종류의 큰 plasmid DNA (45,000, 38,500, 23,000)을 가졌으며, $30^{\circ}C$와 pH7.0에서 0.5%(v/v)의 에탄올을 이용 하여 빼른 성장을 하였다($t_{d}$=6.5시간), 이 세균은 메탄올은 울온 여러까지 종듀의 당, 유기산, 아미노산, 아민 및 알코올을 이용하여 성장할 수 있었고, 메탄올은 serine pathway를 통하여 이 세균의 세포 구성물질로 전환됨을 알 수 있었다.

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Evidence for a Common Molecular Basis for Sequence Recognition of N3-Guanine and N3-Adenine DNA Adducts Involving the Covalent Bonding Reaction of (+)-CC-1065

  • Park, Hyun-Ju
    • Archives of Pharmacal Research
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    • 제25권1호
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    • pp.11-24
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    • 2002
  • The antitumor antibiotic (+)-CC-1065 can alkylate N3 of guanine in certain sequences. A previous high-field $^1H$ NMR study on the$(+)-CC-1065d[GCGCAATTG*CGC]_2$ adduct ($^*$ indicates the drug alkylation site) showed that drag modification on N3 of guanine results in protonation of the cross-strand cytosine [Park, H-J.; Hurley, L. H. J. Am. Chem. Soc.1997, 119,629]. In this contribution we describe a further analysis of the NMR data sets together with restrained molecular dynamics. This study provides not only a solution structure of the (+)-CC-1065(N3- guanine) DNA duplex adduct but also new insight into the molecular basis for the sequence- specific interaction between (+)-CC-1065 and N3-guanine in the DNA duplex. On the basis of NOESY data, we propose that the narrow minor groove at the 7T8T step and conformational kinks at the junctions of 16C17A and 18A19T are both related to DNA bending in the drugDNA adduct. Analysis of the one-dimensional $^1H$ NMR (in $H_2O$) data and rMD trajectories strongly suggests that hydrogen bonding linkages between the 8-OH group of the (+)-CC-1065 A-sub-unit and the 9G10C phosphate via a water molecule are present. All the phenomena observed here in the (+)-CC-1065(N3-guanine) adduct at 5'$-AATTG^*$are reminiscent of those obtained from the studies on the (+)-CC-1065(N3-adenine) adduct at $5'-AGTTA^*$, suggesting that (+)-CC-1065 takes advantage of the conformational flexibility of the 5'-TPu step to entrap the bent structure required for the covalent bonding reaction. This study reveals a common molecular basis for (+)-CC-1065 alkylation at both $5'-TTG^*$ and $5'-TTA^*$, which involves a trapping out of sequence-dependent DNA conformational flexibility as well as sequence-dependent general acid and general base catalysis by duplex DNA.

백혈병 세포주에 대한 $(\pm)$-ar-Turmerone, 자근 및 황금추출물에 의한 항암제의 세포독성 증강효과 (Augmentation of the Cytotoxic Effects of Anticancer Drugs by $(\pm)$-ar-Turmerone and Extracts of the Lithosperma and Scutellaria Roots against Human Leukemia Cell Lines)

  • 이윤영;유관희;김삼용;안병준
    • 약학회지
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    • 제35권3호
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    • pp.203-215
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    • 1991
  • Using the calorimetric [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT)assay, we evaluated the chemosensitivity of 8 anticancer drugs{vincristine(VCR), vinblastine(VBL), adriamycin(ADR), cisplatin(CPDD), etoposide(VP-16), cytosine arabinoside(ara-C), bleomycin (Bleo) and cyclophosphamide(CYC)} and the cytotoxicity-enhancing effects of ($\pm$)-ar-turmerone and the extracts of the crude drugs {Lithospermum eythrorhizon(LE) and Scutellaria baicalensis (SB)} on the above mentioned anticancer drugs against HL-60 and KG-1 cells among 8 anticancer drugs, VCR, VBL, ADR, and CPDD inhibited the growth of both cell lines by more than 50%, while VP-16, ara-C, Bleo, and CYC were less effective. ($\pm$)-ar-Turmerone had significant inhibitory effects against both cell lines, showing the ID$_{50}$ values of 11.730 $\mu\textrm{g}$/ml and 0.292 $\mu\textrm{g}$/ml for HL-60 and KG-1 cells. respectively. But the extracts of LE and SB roots showed no significant cytotoxic effects. According to ID$_{50}$ values, the cytotoxicities of VCR, VBL and ADR against HL-60 were enhanced two, eight and three times by mixing ($\pm$)-ar-turmerone, five, seven and three times by adding the extract of LE root, and twenty, six and three times by mixing the extract of SB root, respectively. The cytotoxicities of the above mentioned drugs against KG-1 cell were enhanced two, seven and three times by mixing ($\pm$)-ar-turmerone, two, three and three times by combining wilth the extract of LB root, and two, five and two times by adding the extract of SB root, respectively. The cytotoxicity-potentiating effects of ($\pm$)-ar-turmerone and the extracts of LE and SB roots against HL-60 cell were greater than KG-1 cell.

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Gene expression and promoter methylation of porcine uncoupling protein 3 gene

  • Lin, Ruiyi;Lin, Weimin;Chen, Qiaohui;Huo, Jianchao;Hu, Yuping;Ye, Junxiao;Xu, Jingya;Xiao, Tianfang
    • Asian-Australasian Journal of Animal Sciences
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    • 제32권2호
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    • pp.170-175
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    • 2019
  • Objective: Uncoupling protein 3 gene (UCP3) is a candidate gene associated with the meat quality of pigs. The aim of this study was to explore the regulation mechanism of UCP3 expression and provide a theoretical basis for the research of the function of porcine UCP3 gene in meat quality. Methods: Bisulfite sequencing polymerase chain reaction (PCR) and quantitative real-time PCR (Q-PCR) were used to analyze the methylation of UCP3 5′-flanking region and UCP3 mRNA expression in the adipose tissue or skeletal muscle of three pig breeds at different ages (1, 90, 210-day-old Putian Black pig; 90-day-old Duroc; and 90-day-old Dupu). Results: Results showed that two cytosine-guanine dinucleotide (CpG) islands are present in the promoter region of porcine UCP3 gene. The second CpG island located in the core promoter region contained 9 CpG sites. The methylation level of CpG island 2 was lower in the adipose tissue and skeletal muscle of 90-day-old Putian Black pigs compared with 1-day-old and 210-day-old Putian Black pigs, and the difference also existed in the skeletal muscle among the three 90-day-old pig breeds. Furthermore, the obvious changing difference of UCP3 mRNA expression was observed in the skeletal muscle of different groups. However, the difference of methylation status and expression level of UCP3 gene was not significant in the adipose tissue. Conclusion: Our data indicate that UCP3 mRNA expression level was associated with the methylation status of UCP3 promoter in the skeletal muscle of pigs.

Genotype-phenotype correlations in pediatric patients with myotonic dystrophy type 1

  • Kim, Hyeong Jung;Na, Ji-Hoon;Lee, Young-Mock
    • Clinical and Experimental Pediatrics
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    • 제62권2호
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    • pp.55-61
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    • 2019
  • Purpose: Myotonic dystrophy, also known as dystrophia myotonica (DM), is an autosomal dominant disorder with 2 genetically distinct forms. DM type 1 (DM1) is the more common form and is caused by abnormal expansion of cytosine/thymine/guanine (CTG) repeats in the DM protein kinase (DMPK ) gene. Our study aimed to determine whether the age of onset is correlated with CTG repeat length in a population of pediatric patients with DM1. Methods: We retrospectively identified 30 pediatric patients with DM1 that underwent DMPK testing, of which the clinical data of 17 was sufficient. The cohort was divided into 2 subgroups based on the clinical phenotype (congenital-onset vs. late-onset) and number of CTG repeats (<1,000 vs. ${\geq}1,000$). Results: We found no significant difference between the age of onset and CTG repeat length in our pediatric patient population. Based on clinical subgrouping, we found that the congenital-onset subgroup was statistically different with respect to several variables, including prematurity, rate of admission to neonatal intensive care unit, need for respiratory support at birth, hypotonia, dysphagia, ventilator dependence, and functional status on last visit, compared to the late-onset subgroup. Based on genetic subgrouping, we found a single variable (poor feeding in neonate) that was significantly different in the large CTG subgroup than that in the small CTG subgroup. Conclusion: Clinical variables exhibiting statistically significant differences between the subgroups should be focused on prognosis and designing tailored management approaches for the patients; our findings will contribute to achieve this important goal for treating patients with DM1.

Identification of Serial DNA Methylation Changes in the Blood Samples of Patients with Lung Cancer

  • Moon, Da Hye;Kwon, Sung Ok;Kim, Woo Jin;Hong, Yoonki
    • Tuberculosis and Respiratory Diseases
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    • 제82권2호
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    • pp.126-132
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    • 2019
  • Background: The development of lung cancer results from the interaction between genetic mutations and dynamic epigenetic alterations, although the exact mechanisms are not completely understood. Changes in DNA methylation may be a promising biomarker for early detection and prognosis of lung cancer. We evaluated the serial changes in genome-wide DNA methylation patterns in blood samples of lung cancer patients. Methods: Blood samples were obtained for three consecutive years from three patients (2 years before, 1 year before, and after lung cancer detection) and from three control subjects (without lung cancer). We used the MethylationEPIC BeadChip method, which covers the 850,000 bp cytosine-phosphate-guanine (CpG) site, to conduct an epigenome-wide analysis. Significant differentially methylated regions (DMRs) were identified using p-values <0.05 in a correlation test identifying serial methylation changes and serial increase or decrease in ${\beta}$ value above 0.1 for three consecutive years. Results: We found three significant CpG sites with differentially methylated ${\beta}$ values and 7,105 CpG sites with significant correlation from control patients without lung cancer. However, there were no significant DMRs. In contrast, we found 11 significant CpG sites with differentially methylated ${\beta}$ values and 10,562 CpG sites with significant correlation from patients with lung cancer. There were two significant DMRs: cg21126229 (RNF212) and cg27098574 (BCAR1). Conclusion: This study revealed DNA methylation changes that might be implicated in lung cancer development. The DNA methylation changes may be the possible candidate target regions for the early detection and prevention of lung cancer.

Development of CRISPR technology for precise single-base genome editing: a brief review

  • Lee, Hyomin K.;Oh, Yeounsun;Hong, Juyoung;Lee, Seung Hwan;Hur, Junho K.
    • BMB Reports
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    • 제54권2호
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    • pp.98-105
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    • 2021
  • The clustered regularly interspaced short palindromic repeats (CRISPR) system is a family of DNA sequences originally discovered as a type of acquired immunity in prokaryotes such as bacteria and archaea. In many CRISPR systems, the functional ribonucleoproteins (RNPs) are composed of CRISPR protein and guide RNAs. They selectively bind and cleave specific target DNAs or RNAs, based on sequences complementary to the guide RNA. The specific targeted cleavage of the nucleic acids by CRISPR has been broadly utilized in genome editing methods. In the process of genome editing of eukaryotic cells, CRISPR-mediated DNA double-strand breaks (DSB) at specific genomic loci activate the endogenous DNA repair systems and induce mutations at the target sites with high efficiencies. Two of the major endogenous DNA repair machineries are non-homologous end joining (NHEJ) and homology-directed repair (HDR). In case of DSB, the two repair pathways operate in competition, resulting in several possible outcomes including deletions, insertions, and substitutions. Due to the inherent stochasticity of DSB-based genome editing methods, it was difficult to achieve defined single-base changes without unanticipated random mutation patterns. In order to overcome the heterogeneity in DSB-mediated genome editing, novel methods have been developed to incorporate precise single-base level changes without inducing DSB. The approaches utilized catalytically compromised CRISPR in conjunction with base-modifying enzymes and DNA polymerases, to accomplish highly efficient and precise genome editing of single and multiple bases. In this review, we introduce some of the advances in single-base level CRISPR genome editing methods and their applications.

Maternal undernutrition alters the skeletal muscle development and methylation of myogenic factors in goat offspring

  • Zhou, Xiaoling;Yan, Qiongxian;Liu, Liling;Chen, Genyuan;Tang, Shaoxun;He, Zhixiong;Tan, Zhiliang
    • Animal Bioscience
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    • 제35권6호
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    • pp.847-857
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    • 2022
  • Objective: The effects of maternal undernutrition during midgestation on muscle fiber histology, myosin heavy chain (MyHC) expression, methylation modification of myogenic factors, and the mammalian target of rapamycin (mTOR) signaling pathway in the skeletal muscles of prenatal and postnatal goats were examined. Methods: Twenty-four pregnant goats were assigned to a control (100% of the nutrients requirement, n = 12) or a restricted group (60% of the nutrients requirement, n = 12) between 45 and 100 days of gestation. Descendants were harvested at day 100 of gestation and at day 90 after birth to collect the femoris muscle tissue. Results: Maternal undernutrition increased (p<0.05) the fiber area of the vastus muscle in the fetuses and enhanced (p<0.01) the proportions of MyHCI and MyHCIIA fibers in offspring, while the proportion of MyHCIIX fibers was decreased (p<0.01). DNA methylation at the +530 cytosine-guanine dinucleotide (CpG) site of the myogenic factor 5 (MYF5) promoter in restricted fetuses was increased (p<0.05), but the methylation of the MYF5 gene at the +274,280 CpG site and of the myogenic differentiation (MYOD) gene at the +252 CpG site in restricted kids was reduced (p<0.05). mTOR protein signals were down-regulated (p<0.05) in the restricted offspring. Conclusion: Maternal undernutrition altered the muscle fiber type in offspring, but its relationship with methylation in the promoter regions of myogenic genes needs to be elucidated.