• Title/Summary/Keyword: Guanine

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Secondary Structure for RNA Aptamers Binding to Guanine-Rich Sequence in the 5'-UTR RNA of N-Ras Oncogene

  • Cho, Bongrae
    • Journal of the Korean Chemical Society
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    • v.65 no.2
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    • pp.121-124
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    • 2021
  • RNA molecules which bind to the G-rich sequence in the 5'-UTR RNA which plays an important role in expression of N-ras, were selected. The secondary structures of five selected RNA aptamers including primer sequence were found by the CLC RNA workbench ver. 4.2 program (www.clcbio.com) and investigated with RNA structural probes such as RNase T1 which has specificity for a G in single-stranded region, RNase V1 specific for double strand and nuclease S1 specific for single strand. The generalized secondary structure model was proposed and characterized. It was composed of a central long double strand region flanked by single strand region at both end sides. The double strand region had an internal single-strand region and bulges. The single strand loop in the right side was composed of four or five nucleotides.

Expression and Distribution of the Guanine Nucleotide-binding Protein Subunit Alpha-s in Mice Skin Tissues and Its Association with White and Black Coat Colors

  • Yin, Zhihong;Zhao, Xin;Wang, Zhun;Li, Zhen;Bai, Rui;Yang, Shanshan;Zhao, Min;Pang, Quanhai
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.10
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    • pp.1392-1397
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    • 2016
  • Guanine nucleotide-binding protein subunit alpha-s ($Gn{\alpha}s$) is a small subunit of the G protein-couple signaling pathway, which is involved in the formation of coat color. The expression level and distribution of $Gn{\alpha}s$ were detected by quantitative real-time-polymerase chain reaction (qPCR), western blot, and immunohistochemistry to investigate the underlying mechanisms of coat color in white and black skin tissues of mice. qPCR and western blot results suggested that $Gn{\alpha}s$ was expressed at significantly higher levels in black mice compared with that of white mice, and transcripts and protein possessed the same expression in both colors. Immunohistochemistry demonstrated $Gn{\alpha}s$ staining in the root sheath and dermal papilla in hair follicle of mice skins. The results indicated that the $Gn{\alpha}s$ gene was expressed in both white and black skin tissues, and the expression level of $Gn{\alpha}s$ in the two types of color was different. Therefore, $Gn{\alpha}s$ may be involved in the coat color formation in mice.

Studies on the Chemical Synthesis of Aflatoxin-DNA Adduct (Aflatoxin-DNA Adduct의 화학합성에 관한 연구)

  • Choi, Sang-Kyung;Kim, Sung-Young;Kang, Jin-Soon;Chung, Duck-Hwa
    • Korean Journal of Food Science and Technology
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    • v.24 no.4
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    • pp.367-370
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    • 1992
  • Aflatoxins are highly carcinogenic agents consistantly found as contaminants in human food supplies in many areas of the world and epidemiologically linked to incidence of human liver cancer. To examine the carcinogenic action of aflatoxin $B_1$, aflatoxin $B_1-DNA$ adducts were chemically synhtesized with the reaction of 20 mg calf thymus DNA, and 8 mg standard aflatoxin $B_1$. Since DNA molecule was too large for analysis, it was fragmented by acid hydrolysis and heat. The fragmented aflatoxin $B_1-DNA$ adducts were selectively concentrated by immunoaffinity column procedure and confirmed by HPLC method. The main component was aflatoxin $B_1-guanine$ adduct, which was quantatively measured as 5.2 mg aflatoxin $B_1$.

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Antigenotoxicity of Ginseng Petroleum Ether Extract and its Action Mechanism (인삼 지용성성분인 유전독성억제효과와 작용기전)

  • 허문영
    • Journal of Food Hygiene and Safety
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    • v.13 no.3
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    • pp.243-251
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    • 1998
  • Panax ginseng C.A. Meyer has been extensively used in the traditional oriental medicine as a restorative, tonic and prophylatic agent. Petroleum ether extract of panax ginseng C.A. Meyer (GPE) and its several fractions (PI-P5) were tested for the evaluation of antigenotoxicity against N-methyl-N-nitrosourea (MNU) and benzo(a)pyrene [B(a)P]-induced micronucleated reticulocytes in mouse peripheral blood. GPE and P2 showed more significant anticlastogenicity than other fractions did. To elucidate the anticlastogenic action mechanism of GPE and P2 against B(a)P, the alteration of B(a)P metabolism was studied. GPE and P2 inhibited B(a)P metabolism in the presence of 8-9 mix and decreased B(a)P-DNA binding in calf thymus DNA with 8-9 mix. They also decreased [$^3H$] MNU induced DNA binding and methylation to 7-methyl guanine and $O^{6}-methyl$ guanine adducts in calf thymus DNA by RPLC analysis. These results suggest that the anticlastogenicity of GPE and P2 on the B(a)P or MNU-induced clastogenicity is due to decrease of DNA binding with B(a)P or MNU, the inhibition of metabolism with B(a)P and the inhibition of methylation in DNA. Therefore, GPE and P2 may be useful chemopreventive agents of alkylating agent like MNU and secondary carcinogen like B(a)P.

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Degradation of Nucleotides and Their Related Compounds During the Fermentation of Oyster (굴젓 숙성중(熟成中) 핵산(核酸) 관련물질(關聯物質)의 변화(變化))

  • Sung, Nak-Ju
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.7 no.2
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    • pp.1-6
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    • 1978
  • Changes of nucleotides and their related compounds during the fermentation of oyster were analyzed by high speed liquid chromatography. In raw oyster, dominant 5'-UMP was $26.1{\mu}mole/g$ and the content of uracil, hypoxanthine, 5'-GMP were 5.2, 3.8, 2.8 and $2.7{\mu}mole/g$ on moisture and salt free base, respectively. The content of cytosine, 2',3'-CMP, 5'-AMP and 2',3'-GMP were lower than $1.0{\mu}mole/g$ and guanine were detected in trace amount. 5'-UMP, uracil, hypoxanthine, 5'-IMP and 5'-GMP were abundant in both raw sample and fermented products. 5'-UMP and 5'-IMP were decreased slowly while 5'-AMP, 2'3'-CMP, cytosine and guanine were increased during the fermentation, and the increase of 5'-GMP and uracil were fluctuated. The content of hypoxanthine in raw oyster was increased to 3.1, 4.2 and 7.7 times of raw sample after 19, 36 and 68 days of fermentation, respectively.

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Antigenotoxicity of Galangin and its Action Mechanism (Galangin의 유전독성 억제효과와 작용기전)

  • 허문영;류재천
    • Environmental Mutagens and Carcinogens
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    • v.18 no.2
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    • pp.77-82
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    • 1998
  • In order to compare the suppressive effect of galangin on the genotoxicity by N-methyl-N-nitrosourea (MNU) or benzo[a]pyrene B(a)P, in vivo micronycleus test using mouse peripheral blood and in vitro sister chromatid exchange(SCE) test using mouse spleen lymphocytes were performed. MNU or B(a)P-induced micronucleated reticulocytes in vivo was decreased by the simultaneous treatment of galangin. MNU or B(a)P-induced SCEs in vitro was also decreased by the simultaneous treatment of galangin. On the other hand, the determinations of [$^3$H]MNU-induced total DNA binding and methylated DNA were performed to find out the mechanism of action. [$^3$H]MNU-induced total DNA binding was inhibited by the treatment of galangin in calf thymus DNA. HPLC analysis of DNA hydrolysates showed that galangin caused a decrease of 7-methyl guanine and $O^{6}$-methyl guanine in calf thymus DNA. To elucidate the action mechanism of galangin against B(a)P, alteration of B(a)P metabolism was studied. Galangin inhibited B(a)P metabolism in the presence of S-9 mix and decreased B(a)P-DNA binding in calf thymus DNA with S-9 mix.

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