• Biotechnology and Bioprocess Engineering:BBE
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• 제10권3호
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• pp.205-211
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• 2005

Water-soluble polyethyleneimine (PE) derivatives containing nucleic acid bases and hydrophilic amino acids such as homoserine (Hse) and serine were prepared by the activated ester method as nucleic acid models. From spectroscopic measurements, the polymers were found to interact with DNA accompanied by an induction of conformational change. Hypochromicity in UV spectra indicated that a stable polymer complex was formed between poly (A) with PEI­Hse-Ura by complementary hydrogen bonding with equimolar nucleic base units (adenine:uracil=1:1). The induced conformation of DNA by the interaction with the polymer containing uracil and homoserine (PEI-Hse-Ura) was concluded to be a super triple helical structure. The formation of the polymer complex, DNA: PEI-Hse-Ura, was found to be affected by the presence of metal ions such as $Ca^{2+}\;and\;Cu^{2+}$.

• Bulletin of the Korean Chemical Society
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• 제18권5호
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• pp.510-514
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• 1997

We studied the interaction of 4',6-diamidino-2-phenylindole (DAPI) with single stranded poly(dA) using optical spectroscopic methods, including absorption, circular dichroism (CD), and fluorescence spectroscopy. The temperature-dependent conformation of poly(dA) was also investigated. The conformation of poly(dA) varied with temperature, which is explained by the stacking-destacking process of the adenine bases, resulting from the sugar conformation. The hypochromicity and red-shift in the absorption spectroscopy, the lack of CD change in the drag absorption region, and the fluorescence behavior, especially a great accessibility of the I2 quencher to the poly(dA)-bound DAPI, suggest that DAPI binds to the outside of poly(dA). The Job plot for the DAPI-poly(dA) mixture demonstrated that a stoichiometry of one DAPI molecule binds to the one phosphate of poly(dA).

• 대한화학회지
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• 제55권2호
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• pp.177-182
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• 2011

이케토형 리간드는 thiophene-2-aldehyde와 acetylacetone의 Knoevenagel 축합반응을 통해 합성하였으며, 이를 이용하여 Cu(II), Ni(II) 및Co(II) 염화물의 착물을 합성하였다. 모든 착물의 특성은 다양한 물리-화학적 방법으로 규명하였다. 몰전기전도도 결과로부터 이들 착물이 이온성을 가짐을 알았다. 전자 및 EPR 스펙트럼을 통해 구리(II) 이온이 사각평면 기하구조를 가짐을 알았다. 구리(II) 착물과 CTDNA(송아지 thymus DNA)의 상호작용을 흡수 스펙트럼과 순환 전압전류법으로 연구하였다. $k_{obs}$ 대 [DNA]의 도시는 선형을 보였는데, 이는 유사-1차반응을 의미한다. 순환 전압전류 그림으로부터 구리(II) 착물이 각각 -0.240 V와 -0.194 V의 $E_{1/2}$ 값을 갖는 일전자 Cu(II)/Cu(I) 산화-환원 쌍에 대해 준가역적임을 알았다. CTDNA를 첨가한 경우, $E_{1/2}$값이 각각168 mV와 18 mV 이동하였고 Ep 값도 감소하였다. CTDNA의 존재 하에 $E_{1/2}$이 이처럼 이동하는 것은 구리(II) 착물이 CTDNA에 강하게 결합됨을 의미한다.