• 한국자기공명학회논문지
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• 제1권1호
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• pp.31-44
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• 1997

The effect of the binding of CRP to the symmetrically synthetic 22, 28, and 30 bp lac promoter was investigated by 1H NMR. The binding of cAMP*CRP to the 22 bp DNA did not bring about any changes in the chemical shift values, but did cause selective line broadening of imino proton resonances of specific base pairs. However, The binding of cAMP*CRP to the 28 and 30 bp DNA brought about large changes on the imino proton resonances that seems to be induced by DNA bending. We studied also the role of cAMP as an activator of DNA/CRP complex formation by gel mobility shift assay. Gel mobility shift assay revealed that the cAMP*CRP complex was not able to bind to the 22 bp DNA fragment, but was able to bind to the 28 bp DNA fragment of lac promoter region.

• Clinical and Experimental Reproductive Medicine
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• 제46권1호
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• pp.8-13
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• 2019

Objective: Density gradient centrifugation (DGC) is frequently used to isolate high-motility fractions of spermatozoa. We compared the efficacy of four DGC media in terms of the percentage of morphologically normal spermatozoa, DNA fragmentation level, and hyaluronic acid (HA) binding ability. Methods: Thirty men with a total motile spermatozoa count > 80 million participated. Semen samples were divided into four aliquots, which were processed using PureSperm, PureCeption, Sidney, and SpermGrad media, respectively. The DNA fragmentation level was measured using the Halosperm assay kit and HA binding ability was measured using the HBA assay kit. Results: The mean percentage of morphologically normal spermatozoa was significantly enhanced after DGC using all four media (10.3%, 9.9%, 9.8%, and 10.7%, respectively; p< 0.05 for each when compared with 6.9% in raw semen). The DNA fragmentation level was significantly reduced after DGC using PureSperm, PureCeption, and SpermGrad media (6.0%, 6.5%, and 4.9%, respectively; p< 0.05 for each when compared with 11.2% in raw semen), but not after DGC using Sidney media (8.5%, p> 0.05). HA binding ability did not change after DGC using any of the four media. Conclusion: The four media were equally effective for obtaining a sperm fraction with highly motile, morphologically normal sperm. PureSperm, PureCeption, and SpermGrad media were equally effective for acquiring a sperm fraction with less DNA fragmentation.

• BMB Reports
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• 제28권1호
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• pp.1-5
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• 1995

The effect of 6-sulfooxymethyl benzo(a)pyrene (SMBP) on conformational changes of calf thymus DNA was investigated. As SMBP is a strong electrophile, the covalent binding of SMBP to DNA should distort three dimensional conformation of DNA at the binding sites. A formaldehyde-unwinding methods were used to determine the rate of DNA denaturation. The increase in absorbance at 251nm was detected by addition of formaldehyde following treatment with SMBP. SMBP changed supercoiled DNA to relaxed and linear DNA as determined by electrophoresis, which was similar to the change in DNA due to in vitro treatment with benzo(a) pyrene diol epoxide. Treatment with SMBP completely denatured DNA under alkaline conditions. However, DNA was nicked or partially denatured under neutral condition. The absorption band of DNA was increased by the treatment with SMBP in V79 cells, which may be explained by the formation of stabilized SMBP-DNA adduct.

• Bulletin of the Korean Chemical Society
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• 제28권12호
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• pp.2539-2542
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• 2007

• Bulletin of the Korean Chemical Society
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• 제34권3호
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• pp.749-752
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• 2013

Trehalose-tethered monomeric and dimeric berberines were synthesized in 50% and 30% from the reaction of berberrubine with 6-tosyl-${\alpha}$,${\alpha}^{\prime}$-trehalose and 6,6'-ditosyl-${\alpha}$,${\alpha}^{\prime}$-trehalose, respectively, and fully characterized by MS (HR and ESI) and NMR ($^1H$, $^{13}C$, COSY and HSQC). Spectrophotometric and spectrofluorimetric titrations indicated that compared with berberine, trehalose-tethered monomeric berberine had comparable DNA-binding affinity toward calf-thymus DNA, whereas trehalose-spaced dimeric berberine exhibited higher DNA-binding affinity. The potential application of these conjugates is also briefly discussed.

• 한국자기공명학회논문지
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• 제5권2호
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• pp.118-129
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• 2001

Binding interactions of cationic porphyrins, T4MPyP and TMAP with DNA oligomer d(CGCGAATTCGCG), were studied with NMR spectroscopy, W and CD spectroscopic method. Two porphyrins showed significant differences in NMR, UV and CD data upon binding to DNA. T4MPyP was considered to position more closely to DNA bases through partial intercalation as well as ionic intercalation between the positive charges of porphyrin and phosphate group of DNA at 5’-GC-3’steps. Contrast to this, TMAP was thought to bind to phosphate of DNA more or less outside of the groove.

• Archives of Pharmacal Research
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• 제10권2호
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• pp.110-114
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• 1987

To correlate the conformational changes of DNA (Calf Thymus) with entrapment of DNA into liposomes, the effect of ions ($Na^+$, $Mg^{++}$on the entrapment of calf thymus DNA into liposomes was investigated. The effect of divalent ion ($Mg^{++}$ on the structural changes of DNA indicated by decrease of observed ellipticity at 274 nm and nonspecific binding of DNA to lipid bilayers was greater than monovalent ion ($\Na^+$). But the efficiency of DNA encapsulated was not altered. These results show that entrapment of DNA into liposomes is not due to nonspecific binding and structural changes because of electrostatic forces but to mechanical capture of DNA by the internal aqueous space of liposomes although divalent ion contributes large structural changes and more nonspecific association of DNA with liposomes due to strong charges.

• Journal of Ginseng Research
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• 제13권1호
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• pp.37-41
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• 1989

Benzo(a)pyrene(BP)의 monooxygenase(AHH)에 의해서 생성된 반응성 대사물질들의 in vitro DNA와의 결합 및 BP 대사에 관여하는 효소들의 활성도에 미치는 인삼 물추출물의 영향을 조사하였으며, DNA-BP metabolite adduct들은 Sephadex LH-20 column으로 chromatography하여 5개의 major peak 들을 얻었다. 이 peak 들을 극성이 큰 순서대로 A부터 E까지 임의로 정하고 5개의 peak들을 7,8-diol-9,10-oxide(A), 7,8-oxide(B). 4,5-oxide(C), 9-HO-BP(D & E) adduct들로 잠정적으로 확인하였다. Peak A, C, D 그리고 E는 각각 대조군의 30, 15, 20 그리고 30%로 감소되었으며 peak B는 의미있는 변화를 보이지 않았다. DNA-BP 결합 억제와 관련하여 in vitro와 in vivo 투여시의 경향이 유사하여 EH의 활성도만 BP투여 대조군보다 38%정도 의미있게 유도되었다.

• 대한화학회지
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• 제46권2호
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• pp.151-156
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• 2002

Fucoidan은 갈조류에 다량 함유되어있는 다당류로서 항암작용, 항혈응고작용, 항혈전작용, 항염증작용, 항virus작용과 같은 생리활성작용력을 가지고 있어 최근 많은 연구가 수행되어지고 있다. 본 논문은 갈조류에서 fucoidan을 추출 하여 그 항암활성을 SV40 DNA replication assay, RPA-ssDNA binding assay, 그리고 MCF7 cell growth inhibition assay를 이용하여 알아보았으며 이 항암활성은 fucoidan의 황산기가 중요한 역할을 하고 있음을 알아내었다. 화학적으로 황산기의 함유량을 증가시킨 fucoidan이 황산기의 함유량을 제거시킨 fucoidan보다 항암활성이 뛰어났고, 이는 RPA의 ssDNA 결함력을 떨어 EM리기 때문이라 예측되어 진다. 본 연구는 한국산 갈조류에서 추출한 황산기를 함유한 fucoidan의 항암활성능력을 보여주었다.

• Journal of Microbiology and Biotechnology
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• 제12권4호
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• pp.622-627
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• 2002

Diphtheria toxin repressor (DtxR) binds to approximately 30 to 35-bp regions containing an interrupted 9-bp inverted repeat within a 19-bp core sequence. The core sequence is fairly conserved and critical for DtxR binding. The flanking regions that are consisted of 5 to 8 more of nucleotides from the core are also required for DtxR binding. The nucleotides in both flanking regions are A-T rich. To examine whether the A-T nucleotides in both flanking regions from the core have significant roles for DtxR binding, a DNA fragment was constructed based on the diphtheria tox promoter/operator, and DNA fragments with substitution of A and T nucleotides In the flanking regions to G and C were also constructed. To assess the effect of these substitutions on binding of DtxR and repressibility by DtxR, $\beta$-galactosidase activity from lacZ fused to the region was assessed. Gel mobility shift of the region by purified DtxR was also examined. The DNA fragments containing the mutations in the flanking regions still exhibited repression and mobility shift with DtxR. The core segment with the mutation is still, therefore, recognized by DtxR. Nonetheless, the results from the assays indicated that the substitution significantly decreased repression of the operator by DtxR in vivo under high-iron condition and decreased binding of DtxR to the operator. These results suggest that A and T nucleotides fur both flanking regions are preferred for the binding of DtxR.