Vitamin D-2 at high and low concentrations exert opposing effects on molecular order and dynamics of dipalmitoyl phosphatidylcholine membranes

Date

2001-01-01

Author

Kazanci, N
Toyran, N
Haris, PI
Severcan, Feride

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

135
views

0
downloads

Fourier Transform Infrared spectroscopic studies show that low concentrations of vitamin D-2 (1 and 3 mol %) does not induce significant change in the overall shape of the thermotropic profile of dipalmitoyl phosphatidylcholine (DPPC) membrane. In contrast, at higher concentrations of vitamin D-2 (9 and 12 mol %), the phase transition shifts to lower temperatures and a significant broadening in the phase transition curve is also observed. Low concentration of vitamin D-2 decreases the frequency of the CH2 stretching mode, implying an ordering effect, whilst high concentration of vitamin D-2 disorders the system. Furthermore, at low and high concentrations, vitamin D-2 causes opposing effect on membrane dynamics. It decreases the bandwidth of the CH2 stretching modes at low concentrations while increasing it at high concentrations. We have also observed different actions of vitamin D-2 at low and high concentrations in the deep interior and interfacial region of the membrane, by monitoring the frequency of the CH3 stretching band and C=O stretching bands, respectively

Subject Keywords

Alpha-tocopherol, Different metabolism, Phase-equilibria, Model membranes, Cholesterol, Antioxidant, Tamoxifen, Anticancer, Resonance

URI

https://hdl.handle.net/11511/53127

Journal

SPECTROSCOPY-AN INTERNATIONAL JOURNAL

DOI

https://doi.org/10.1155/2001/890975

Collections

Department of Biology, Article

Suggestions

OpenMETU
Core

Vitamin E Decreases the Order of the Phospholipid Model Membranes in the Gel Phase: An FTIR Study Severcan, Feride (Portland Press Ltd., 1997-4-1) The effect of α-tocopherol on the frequency of the CH2 stretching bands of infrared spectra of dipalmitoylphosphotidylcholine multibilayers has been investigated, both in H2O and 2H2O buffer, to determine the reason for the discrepancy in the literature between the results of different spectroscopic techniques relating to the effect of α-tocopherol on membrane order in the gel phase. In contrast to previous FTIR studies, the present FTIR results indicate that αT increases the frequencies of the CH2 stretchi...
Specific Heat of NH4Cl and NH4BrxCl1-x Crystals Close to the Ferro-Ordered Phase Yurtseven, Hasan Hamit (2009-04-01) This study gives calculation of the specific heat C-VI of NH4Cl and NH4BrxCl1-x under the Ising model for the transition between the disordered (D) and ferro-ordered O(F) phases in these crystalline systems. Our C-VI values which we calculated for x = 0 and x = 0.04, agree both below and above T-c with the observed C-p data from the literature. Our value of a congruent to 0.1 (T < T-c and T > T-c) is in good agreement with the predicted value of 1/8 (0.125) of a 3D Ising model.
Immobilization of invertase and glucose oxidase in conducting H-type polysiloxane/polypyrrole block copolymers Gursel, A; Alkan, S; Toppare, Levent Kamil; Yagci, Y (Elsevier BV, 2003-01-01) In this study, immobilizations of enzymes, invertase and glucose oxidase, were achieved in conducting copolymers of N-pyrrolyl terminated polydimethylsiloxane/polypyrrole (PDMS/PPy) matrices via electrochemical polymerization. The kinetic parameters, v(max) (maximum reaction rate) and K-m (substrate affinity), of both free and immobilized enzymes were determined. The effect of supporting electrolytes, p-toluene sulfonic acid and sodium dodecyl sulfate, on enzyme activity and film morphologies was examined. ...
Carbon sources affect metabolic capacities of Bacillus species for the production of industrial enzymes: theoretical analyses for serine and neutral proteases and alpha-amylase Çalık, Pınar (Elsevier BV, 2001-07-01) The metabolic fluxes through the central carbon pathways were calculated for the genus Bacillus separately for the enzymes serine alkaline protease (SAP), neutral protease (NP) and alpha -amylase (AMY) on five carbon sources that have different reduction degrees (gamma), to determine the theoretical ultimate limits of the production capacities of Bacillus species and to predict the selective substrate for the media design. Glucose (gamma = 4.0), acetate (gamma = 4.0), and the TCA cycle organic-acids succina...
Angle of graph energy - A spectral measure of resemblance of isomeric molecules Gutman, I; Türker, Burhan Lemi (2003-11-01) A method, elaborated earlier by one of the present authors, for measuring the structural resemblance of isomeric alternant conjugated hydrocarbons, based on a graph-spectral quantity theta, called the angle of total pi-electron energy approach has been extended now to arbitrary molecules. Some general properties of theta have been established.

Citation Formats

N. Kazanci, N. Toyran, P. Haris, and F. Severcan, “Vitamin D-2 at high and low concentrations exert opposing effects on molecular order and dynamics of dipalmitoyl phosphatidylcholine membranes,” SPECTROSCOPY-AN INTERNATIONAL JOURNAL, pp. 47–55, 2001, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/53127.