The influence of gramicidin S on the thermotropic phase transition of dipalmitoylphosphatidylglycerol DPPG/GS systems: Experiment and computer model

2004-09-01
Stan, C
Cristescu, CP
Severcan, Feride
Dorohoi, D
The paper presents experimental data recorded by Fourier Tran form Infrared Spectroscopy regarding the influence of the antimicrobial peptide gramicidin (GS) concentration on the thermotropic phase transition of dipalmitoylphosphatidylglycerol (DPPG) lipid bilayer membrane in DPPG/GS systems, as reflected in the change of the bandwidth of the symmetric stretching band of CH2. The samples were investigated cyclically in a temperature range between 26.5degrees and 61.1degreesC which includes the gel to liquid crystal thermotropic phase transition. A computer model based on the influence of the GS concentration on the damping parameter of a linear oscillator modeling the CH2 symmetric stretching band is considered. The results of the computation are in good agreement with the observed behavior.
REVUE ROUMAINE DE CHIMIE

Suggestions

Effects of the non-steroidal anti-inflammatory drug celecoxib on cholesterol containing distearoyl phosphatidylcholine membranes
Sade, Asli; Banerjee, Sreeparna; Severcan, Feride (2011-01-01)
The effects of different concentrations of celecoxib on the acyl chain order, dynamics and the hydration status of the head group and interfacial region of model membranes containing DSPC and cholesterol were investigated in detail using Fourier transform infrared spectroscopy. Our results reveal that regardless of the presence of cholesterol, celecoxib is able to alter the physical properties of membranes. It exerts opposing effects on membrane order at high and low concentrations and decreases membrane fl...
Effect of gramicidin S on the dipalmitoylphosphatidyl-glycerol thermotropic phase transition in DPPG/GS systems: A mathematical approach
Stan, Cristina; Cristescu, C. P.; Severcan, Feride; Dorohoi, Dana (Informa UK Limited, 2006-01-01)
We present a mathematical approach to the experimental data recorded via Fourier transform-infrared spectroscopy regarding the influence of the concentration of the antimicrobial peptide gramicidin S (GS) on the thermotropic phase transition of the dipalmitoylphosphatidyl-glycerol (DPPG) lipid bilayer membrane in DPPG/GS systems. The model is based on the influence of the GS concentration on the parameters of a nonlinear damped oscillator, which models the CH2 symmetric stretching band.
The flow of excitation energy in LHCII monomers: Implications for the structural model of the major plant antenna
Gradinaru, CC; Ozdemir, S; Gulen, D; van Stokkum, IHM; van Grondelle, R; van Amerongen, H (1998-12-01)
Spectral and kinetic information on energy transfer within the light-harvesting complex II (LHCII) monomer was obtained from this subpicosecond transient absorption study, by using selective excitation (663, 669, 672, 678, and 682 nm) of various Chl a absorption bands and detecting the induced changes over the entire Q(y) region (650 -700 nm). It is shown that transfer from the pigment(s) absorbing around 663 nm to the low energy ones occurs in 5 +/- 1 ps, whereas the 670-nm excitation is delivered to the s...
Evolution of SiO2 matrix during the formal-ion of Ge and Si nanocrystals by ion implantation
SERİNCAN, UĞUR; Yerci, Selçuk; KULAKCI, MUSTAFA; Turan, Raşit (2005-10-01)
Fourier transformed infrared spectroscopy (FTIR) has been employed to observe and understand structural variations in SiO2 matrix during the formation of Ge and Si nanocrystals by ion implantation as a function of processing parameters. The Si-O asymmetric stretching peak of absorption spectra were used to monitor the evolution of SiOx (x < 2) films during the annealing process. It was shown that the recovery process in Si-O network is quite different in Ge and Si implanted samples and the deformation cause...
Effect of thermal treatment on secondary structure and conformational change of mushroom polyphenol oxidase (PPO) as food quality related enzyme: A FTIR study
Baltacioglu, Hande; Bayındırlı, Alev; Severcan, Mete; Severcan, Feride (2015-11-15)
In order to understand the conformational changes of polyphenol oxidase (PPO), which is a food quality related enzyme, after thermal treatment, secondary structure changes of the enzyme were analyzed by using Fourier Transform Infrared (FTIR) spectroscopy and compared with the change in enzyme activity in the temperature range of 25-80 degrees C. Fourier self-deconvolution, neural network (NN) and curve-fitting analysis were applied to the amide I band of FTIR spectra for detail analysis of secondary struct...
Citation Formats
C. Stan, C. Cristescu, F. Severcan, and D. Dorohoi, “The influence of gramicidin S on the thermotropic phase transition of dipalmitoylphosphatidylglycerol DPPG/GS systems: Experiment and computer model,” REVUE ROUMAINE DE CHIMIE, pp. 777–782, 2004, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/55195.