• 제목/요약/키워드: Fluorescence anisotropy

검색결과 27건 처리시간 0.019초

Effects of Parathyroid Hormone on the Fluidity of the Plasma Membrane Vesicles of Cultured Osteoblasts

  • Kang, Jung-Sook
    • Journal of Photoscience
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    • 제8권3_4호
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    • pp.87-92
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    • 2001
  • Intramolecular excimer formation of 1,3-di(1-pyrenyl)propane (Py-3-Py) and fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH) were used to investigate the effects of parathyroid hormone (PTH) on the bulk bilayer fluidity of the plasma membrane vesicles isolated from cultured osteoblasts (OB-PMV). In a dose-dependent manner, rat PTH-(1-34) [rPTH-(1-34)] increased the excimer to monomer fluorescence intensity ratio (I'/I) of Py-3-Py and decreased the anisotropy (r) of DPH in OB-PMV. This indicates that PTH increased both the lateral and rotational diffusion of the probes in OB-PMY. Selective quenching of DPH fluorescence by trinitrophenyl groups was utilized to examine the transbilayer fluidity asymmetry of OB-PMV. The anisotropy, limiting anisotropy, and order parameter of DPH in the inner monolayer were 0.024, 0.032, and 0.062 greater than calculated for the outer monolayer of OB-PMY. Selective quenching of DPH fluorescence by trinitrophenyl groups was also utilized to examine the transbilayer effects of PTH on the fluidity of OB-PMV. rPTH-(1-34) had a greater fluidizing effect on the outer monolayer as compared to the inner monolayer of OB-PMV. Thus, it has been proven that PTH exhibits a selective rather than nonselective fluidizing effect within transbilayer domains of OB-PMV.

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황백(黃柏)의 berberine이 DNA의 기능조절에 미치는 영향에 관한 형광이방성 연구 (Fluorescence Anisotropy Study on the Effect of Phellodendri Cortex's Berberine on Regulation of the Function of DNA)

  • 이성경;한효상;허성호
    • 대한본초학회지
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    • 제33권5호
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    • pp.105-110
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    • 2018
  • Objectives : We tried to observe the fluorescence anisotropy and intensity of ethidium ion in the intercalating binding interaction between DNA and ethidium ions in the presence of berberine, and then tried to explain the effect of berberine on the intercalating interaction of ethidium ion with DNA. Methods : DNA(calf thymus DNA), berberine and ethidium bromide(EtBr) were purchased from Sigma-Aldrich Co. Proper amount of each compound was dissolved in 20 mM sodium phosphate buffer(pH 7.0) containing 100 mM of NaCl to prepare stock solutions. Collections of the fluorescence anisotropy and intensity data were performed on JASCO FP-8300 spectrofluorometer equipped with a polarizer and a Peltier temperature controller. The excitation of ethidium ion was done at 550 nm and the emission data were collected at 600 nm. For Stern-Volmer plot, the fluorescence data were collected at $18^{\circ}C$ and $30^{\circ}C$. Results : According to the results of this research, the weak competitive binding pattern between ethidium ion and berberine appeared in binding with DNA at low ratio of DNA to ethidium ion. But at high ratio of DNA to ethidium ion, this weak competition disappeared. Instead, berberine might bind to DNA by intercalating way. In other words, berberine could de-intercalate ethidium ion from DNA at low concentration of DNA relative to ethidium ion, but could not at high concentration of DNA relative to ethidium ion. In addition, the mechanism of fluorescence quenching of ethidium ion could also proceed differently, depending on the ratio of the amount of DNA to that of ethidium ion. Conclusions : The effect of berberine on the DNA-ethidium ion intercalating interaction could work differently, depending on the relative ratio of the amount of DNA to that of ethidium ion. This study also showed that fluorescence anisotropy analysis is very useful method to obtain detailed information for investigation of the complex binding interactions. In order to fully understand the mechanism of action of the pharmacological effect by berberine, studies on the effect of berberine on the action of proteins such as various enzymes closely related to berberine-induced medicinal effects should be continued.

Photophysical Model of 10-Hydroxybenzo[h]quinoline: Internal Conversion and Excited State Intramolecular Proton Transfer

  • Lee, Junghwa;Joo, Taiha
    • Bulletin of the Korean Chemical Society
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    • 제35권3호
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    • pp.881-885
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    • 2014
  • Photophysics of 10-hydroxybenzo[h]quinoline (HBQ) has been in controversy, in particular, on the nature of the electronic states before and after the excited state intramolecular proton transfer (ESIPT), even though the dynamics and mechanism of the ESIPT have been well established. We report highly time resolved fluorescence spectra over the full emission frequency regions of the enol and keto isomers and the anisotropy in time domain to determine the accurate rates of the population decay, spectral relaxation and anisotropy decay of the keto isomer. We have shown that the ~300 fs component observed frequently in ESIPT dynamics arises from the $S_2{\rightarrow}S_1$ internal conversion in the reaction product keto isomer and that the ESIPT occurs from the enol isomer in $S_1$ state to the keto isomer in $S_2$ state.

Barbiturates가 소의 대뇌피질 Synaptosomal Plasma Membrane Vesicles로 부터 추출 제제한 총지질 및 총인지질 인공세포막에 형성된 비대칭적 유동성에 미치는 비대칭적 영향 (Effects of Barbiturates on Transbilayer Fluidity Domains of Phospholipid Model Membrane Monolayers)

  • 윤일;강정숙
    • 대한약리학회지
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    • 제28권1호
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    • pp.103-114
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    • 1992
  • 한국산 2년생 소의 신선한 대뇌피질로 부터 synaptosomal plasma membrane vesicles (SPMV)를 분리한 후 이 SPMV로 부터 추출한 총지질 (SPMVTL) 및 총인지질 (SPMVPL)로서 인공세포막을 제제하였다. SPMVTL 및 SPMVPL의 outer monolayer에 trinitrophenyl groups로 공유결합시킴으로써 형광 probe 1,6-diphenyl-1,3,5-hexatriene (DPH)의 outer monolayer 형광을 선택적으로 소광케한 후 SPMVTL 및 SPMVPL의 inner와 outer monolayer 사이의 비대칭적 유동성 존재 유무를 확인하였던 바 inner monolayer에 비하여 outer monolayer가 유동성이 크다는 것을 확인하였으며 SPMVTL에 비하여 SPMVPL의 유동성이 높았다. 뿐만 아니라 barbiturates는 SPMVTL의 유동성에 대하여는 유의성이 있을 만큼의 증감 효과를 나타내지 않았고 SPMVPL의 유동성은 감소시키되 주로 outer monolayer의 유동성을 감소시킨다는 것을 확인하였으며 barbiturates 종류에 따른 SPMVPL의 총유동성 감소의 크기는 pentobarbital > hexobarbital > amobarbital > phenobarbital의 순이었다.

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지방산 첨가가 리포좀 유동성에 미치는 영향에 관한 연구 (Effect of Fatty Acid on the Membrane Fluidity of Liposomes)

  • 이진선;지경엽;임종주
    • 공업화학
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    • 제28권2호
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    • pp.177-185
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    • 2017
  • 본 연구에서는 스테아르산(SA), 올레산(OA), 리놀레산(LA) 등의 지방산이 지질 소포체 막과의 상호 작용에 미치는 영향에 관하여 살펴보았다. 이를 위하여 지방산 종류 및 농도 변화에 따른 리포좀 평균 입자 크기 및 제타 전위, 리포좀 막의 deformability, fluorescence anisotropy ratio 등을 측정하고 TEM 관찰을 통하여 지방산 첨가가 리포좀 막의 유동성 변화에 미치는 역할에 관하여 살펴보았다. 기본적으로 SA, OA, LA 등의 지방산 첨가는 동일한 경향을 나타내었다. 즉, 지방산을 첨가함에 따라 리포좀이 보다 치밀한 패킹을 갖게 되어서 리포좀의 크기는 감소하고 제타 전위 값은 증가하였으나, 지방산의 과도한 첨가는 리포좀에서 다형(polymorphic) 구조를 가지는 지질 입자 응집체로의 전이를 일으켰다. SA, OA 및 LA 지방산 시스템에서의 최소 리포좀 크기와 가장 치밀한 리포좀 패킹은 레시틴 대비 지방산의 몰 비율이 각각 0.70, 0.50, 0.25인 조건에서 관찰되었으며, 리포좀 막의 deformability와 fluorescence anisotropy ratio 측정에 의한 리포좀 막의 유동성 측정 결과는 TEM 및 입자 크기 측정 결과와 일치함을 알 수 있었다.

Membrane-Ordering Effects of Barbiturates on Pure Phospholipid Model Membranes

  • Knag, Jung-Sook;Chung, Young-Za;Cho, Goon-Jae;Byun, Won-Tan;Yun, Il
    • Archives of Pharmacal Research
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    • 제15권3호
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    • pp.196-203
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    • 1992
  • Intramolecular excimer formation of 1, 3-di(1-pyrenyl)propane (Py-3-Py) and fluorescence polarization of 1, 6-diphenyl-1, 3, 5-hexatriene (DPH) were used to investigate the effects of barbiturates on the fluidity of model membranes of phosphatidycholine (SPMVPC), phosphatidylserine (SPMVPS), and phosphatidylinositol (SPMVPI) fractions of synaptosomal plasma membrane vesicles (SPMV) isolated from bovine cerebral cortex. In a dose-dependent manner, barbiturates decreased the excimer to monomer fluorescence intensity ratio (I'/I) of Py-3-Py and increased the anisotropy(r), rotational relaxation time (P), limiting anisotropy $(r_infty)$, and order parameter (S) of DPH in SPMVPC, SPMVPS and SPMVPI. This indicates that barbiturates decreased both the lateral and rotational diffusion of the probes in SPMVPC, SPMVPS and SPMVPI. The relative potencies of barbiturates in ordering the membranes were in the order: pentobarbital > hexobarbital > amobarbital > phenobarbital. This order correlates well with the anesthetic potencies of barbiturates and the potencies for enhancement of $\gamma$-aminobutyric acid-stimulated chloride uptake. Thus, it is strongly suggested that a close relationship might exist between the membrane ordering effects of barbiturates and the chloride fluxes across SPMV.

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Barbiturates가 소의 신선한 대뇌피질 Synaptosomal Plasma Membrane Vesicles로 부터 추출하여 제제한 Phosphatidylethanolamine 인공세포막의 유동성에 미치는 영향 (Effects of Barbiturates on the Fluidity of Phosphatidylethanolamine Model Membranes)

  • 윤일;김형일;황태호;김종렬;김인세;정용자;신영희;정현옥;강정숙
    • 대한약리학회지
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    • 제26권2호
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    • pp.209-217
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    • 1990
  • Barbiturates가 분자적 약리작용기전 탐구에 기초자료를 제공하기 위하여 소의 신선한 대뇌피질 synaptosomal plasma membrane vesicles로부터 분리제제한 phosphatidylethanolamine인공세포막(SPMVPE)의 유동성에 미치는 barbiturates의 영향을 형광 probe법으로 검색한 결과는 다음과 같다. 1. Pentobarbital, hexobarbital, amobarbital 및 phenobarbital이 기재한 순위로 SPMVPE내 Py-3-Py의 monomer 형광세기에 대한 excimer 형광세기의 비 (I'/I)를 감소시켰다. 2. Pentobarbital, hexobarbital, amobarbital 및 phenobarbital이 기재한 순위로 SPMVPE내 DPH의 polarization, anisotropy, limiting anisotropy, order parameter 및 rotational relaxation time을 증가시켰다. 3. 따라서 위에 제시한 barbiturates가 SPMVPE의 유동성을 유의성있게 감소시킨다는 것을 확인할 수가 있었다.

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Effect of Ganglioside $G_{M3}$ on the Erythrocyte Glucose Transporter (GLUT1): Conformational Changes Measured by Steady-State and Time-Resolved Fluorescence Spectroscopy

  • Yoon, Hae-Jung;Lee, Min-Yung;Jhon, GiI-Ja
    • BMB Reports
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    • 제30권4호
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    • pp.240-245
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    • 1997
  • Interactions between ganglioside $G_{M3}$ and glucose transporter, GLUT1 were studied by measuring the effect of $G_{M3}$ on steady-state and time-resolved fluorescence of purified GLUT1 in synthetic lipids and on the 3-O-methylglucose uptake by human erythrocytes. The intrinsic tryptophan fluorescence showed a GLUT 1 emission maximum of 335 nm, and increased in the presence of $G_{M3}$ by 12% without shifting the emission maximum, The fluorescence lifetimes of intrinsic tryptophan on GLUT1 consisted of a long component of 7.8 ns and a short component of 2,3 ns and $G_{M3}$ increased both lifetime components. Lifetime components were quenched by acrylamide and KI. Acrylarnide-mduced quenching of long-lifetime components was partly recovered by $G_{M3}$ However. KI-induccd quenching of short- and long-lifetime components was not rescued by $G_{M3}$. The anisotropy of 1.6-diphenyl-1.3.5-hexatriene (DPH)-probed dimyristoylphosphatidylcholine (DMPC) model membrane was also increased with $G_{M3}$ incorporation, The transport rate of 3-O-methylglucose increased by 20% with $G_{M3}$ incorporation on the erythrocytes, Therefore, $G_{M3}$ altered the environment of lipid membrane and induced the conformational change of GLUT1.

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Differential Effects of Local Anesthetics on Rate of Rotational Mobility between Hydrocarbon Interior and Surface Region of Model Membrane Outer Monolayer

  • Chung, In-Kyo;Cha, Seong-Kweon;Chung, Yong-Za;Kim, Bong-Sun;Choi, Chang-Hwa;Cho, Goon-Jae;Jang, Hye-Ock;Yun, Il
    • The Korean Journal of Physiology and Pharmacology
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    • 제4권1호
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    • pp.41-46
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    • 2000
  • Using fluorescence polarization of 12-(9-anthroyloxy)stearic acid (12-AS) and 2-(9-anthroyloxy)stearic acid (2-AS), we evaluated the differential effects of local anesthetics on differential rotational rate between the surface (in carbon number 2 and its surroundings including the head group) and the hydrocarbon interior (in carbon number 12 and its surroundings) of the outer monolayer of the total lipid fraction liposome extracted from synaptosomal plasma membrane vesicles. The anisotropy (r) values for the hydrocarbon interior and the surface region of the liposome outer monolayer were $0.078{\pm}0.001$ and $0.114{\pm}0.001,$ respectively. This means that the rate of rotational mobility in the hydrocarbon interior is faster than that of the surface region. In a dose-dependent manner, the local anesthetics decreased the anisotropy of 12-AS in the hydrocarbon interior of the liposome outer monolayer but increased the anisotropy of 2-AS in the surface region of the monolayer. These results indicate that local anesthetics have significant disordering effects on the hydrocarbon interior but have significant ordering effects on the surface region of the liposome outer monolayer.

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