• 한국자기공명학회:학술대회논문집
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• 한국자기공명학회 2000년도 동계총회 및 제16회 자기공명 학술발표회
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• pp.28-28
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• 2000

• Bulletin of the Korean Chemical Society
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• 제6권3호
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• pp.123-124
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• 1985

The optical activity of a fluid in the extreme critical region, where the Ornstein-Zernike theory does not hold, is explicitly obtained. We suggest new experimental methods to measure the critical exponent for correlation function by using the results of circular dichroism and optical rotation given in this paper.

• Bulletin of the Korean Chemical Society
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• 제11권3호
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• pp.254-255
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• 1990

• Journal of Photoscience
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• 제11권1호
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• pp.29-33
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• 2004

The mechanism of interaction of cyanocobalamin (CB) with bovine serum albumin (BSA) has been investigated by spectrofluorometric and circular dichroism methods. Association constant for the CB-BSA system showed that the interaction is non-covalent in nature. Binding studies in the presence of an hydrophobic probe, 8-anilino-l-naphthalene sulphonic acid, sodium salt (ANS) showed that there is hydrophobic interaction between CB and ANS and they do not share common sites in BSA. Stern-Volmer analysis of fluorescence quenching data showed that the fraction of fluorophore (protein) accessible to the quencher (CB) was close to unity indicating thereby that both tryptophan residues of BSA are involved in drug-protein interaction. The rate constant for quenching, greater than $10^{10}$ $M^{-1}$ $s^{-1}$, indicated that the drug binding site is in close proximity to tryptophan residue of BSA. Thermodynamic parameters obtained from data at different temperatures showed that the binding of CB to BSA involves hydrophobic bonds predominantly. Significant increase in concentration of free drug was observed for CB in presence of paracetamol. Circular dichroism studies revealed the change in helicity of BSA due to binding of CB to BSA.

• 대한화학회지
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• 제42권2호
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• pp.143-149
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• 1998

마취제를 purple membrane내 bacteriorhodopsin(bR)에 가했을 때 570nm 흡수 띠는 480nm로 이동한다. 마취제에 의해 유도된 분광학적 변화는 가역적이다. 이러한 평형의 겉보기 pKa(6.3)는 bR에 분산된 마취제의 성질에 의존한다. bR의 전기배향 측정은 비교적 작은 전기장에서도 쉽게 달성될 수 있었으며 이때의 배향각도는 60°이었다. 그러나 마취제로 처리한 bR은 이러한 변화를 관측할 수가 없다. 이들 결과들은 마취제에 의해 발색단과 발색단 주변의 단백질 구조의 민감한 변화가 단백질 매트릭스의 전하를 띈 잔기들의 공간적 배향에 영향을 준 것으로 보인다.

• Bulletin of the Korean Chemical Society
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• 제29권8호
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• pp.1533-1538
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• 2008

Porphyrins generally bind DNA in two different ways with respect to the mixing ratio; monomeric binding at a low mixing ratio and outside stacking at a high mixing ratio. In the present study, CTDNA binding property of a planar structured porphyrin, 5,10,15,20-tetrakis(N-methyl-4-pyridin-4-yl-phenyl)porphyrin (referred to as B-TMPyP) was investigated using absorption, CD, LD, and $LD^r$ spectroscopies. B-TMPyP produced a bisignate CD band, even at the lowest mixing ratio, indicating that B-TMPyP may not have a monomeric binding mode. From the observations of the spectral changes to the absorption, CD, and LD spectra in mixing ratio dependent titrations, B-TMPyP seems to have a quite different stacking type compared to that for the binding of $H_2$TMPyP. Moreover, B-TMPyP produced a CD band of opposite shape in the Soret band region. A qualitative explanation for the observed optical differences is also given.

• 폴리머
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• 제25권5호
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• pp.699-706
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• 2001

연신온도, 연신속도, 연신비 등 연신 조건에 따른 poly(ethylene 2,6-naphthalate) (PEN)의 배향상태 변화를 살펴보았다. 연신온도가 낮을수록 연신속도가 빠를수록 연신비에 따라 큰 복굴절 값을 보이며 FT-IR ATR dichroism 방법으로 구한 배향 특성도 복굴절의 실험결과를 뒷받침하였다. PEN을 $120^{\circ}C$에서 연신하면 무정형사슬 배향함수 ($f_a$)가 연신속도가 빠를수록 높은 값을 갖지만 $141^{\circ}C$에서 연신하면 반대로 연신속도가 빠를수록 낮은 값을 갖게 된다. 이러한 경향은 결정화 속도와 사슬 이완속도와의 관계로부터 설명이 가능하다. X-선 회절 실험 결과로부터 PEN의 naphthalene ring 구조가 필름표면에 평행하게 배열됨을 확인할 수 있었다.

• BMB Reports
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• 제32권6호
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• pp.521-528
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• 1999

The folding of recombinant hepatitis B virus X-protein (rHBx) solubilized from Escherichia coli inclusion bodies was investigated. By sequential dialysis of urea, rHBx was folded into its native structure, which was demonstrated by the efficacy of its transcriptional activation of the adenovirus major late promoter (MLP), fluorescence spectroscopy, and circular dichroism (CD) analysis. The decrease in CD values at 220 nm and a corresponding blue shift of the intrinsic fluorescence emission confirmed the ability of rHBx to refold in lower concentrations of urea, yielding the active protein. Equilibrium and kinetic studies of the refolding of rHBx were carried out by tryptophan fluorescence measurements. From the biphasic nature of the fluorescence curves, the existence of stable intermediate states in the renaturation process was inferred. Reverse phase-high performance liquid chromatography (RP-HPLC) analysis further demonstrated the existence of these intermediates and their apparent compactness.

• 한국자기공명학회논문지
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• 제7권1호
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• pp.37-45
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• 2003

Human CD99 is a ubiquitous 32-kDa transmembrane protein encoded by mic2 gene. Recently it has been reported that expression of a splice variant of CD99 transmembrane protein (Type I and Type II) increases invasive ability of human breast cancer cells. To understand structural basis for cellular functions of CD99 Type II, we have initiated studies on hCD99$\^$TMcytoI/ using circular dichroism (CD) and multi-dimensional NMR spectroscopy. CD spectrum of hCD99$\^$TMytoI/ in the presence of 200mM DPC and CHAPS displayed an existence ${\alpha}$-helical conformation, showing that it could form an ${\alpha}$-helix under membrane environments. In addition, we have found that the cytoplasmic domain of CD99 would form symmetric dimmer in the presence of transmembrane domain. Although it has been rarely figured out the correlation between structure and functional mechanism of hCD99$\^$TMcytoI/, the dimerization or oligomerization would play an important role in its biological function.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 디스플레이 광소자 분야
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• pp.81-84
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• 2002

The chalcogenide glasses of thin films have the superior property of photoinduced anisotrophy(PA). In this study, we observed the linear dichroism(D) using the irradiation with polarized He-Ne laser light, in the $Ag/As_{10}Ge_{10}Se_{15}S_{35}$ multi-layer. Mutilayer structures formed by alternating metal(Ag) and chalcogenide($As_{10}Ge_{10}Se_{15}S_{35}$). The Ag polarized photodoping result in reducing time of saturation anisotrophy and increasing sensitivity of linearly anisotrophy intensity, up to maximum 220%. In the thin films of chalcogenide, the Ag polarized photodoping will be show a capability of new method that suggested more improvement of photoinduced anisotrophy property.