Free volume and dynamics in a lipid bilayer

Gironi, Beatrice; Lapini, Andrea; Ragnoni, Elena; Calvagna, Chiara; Paolantoni, Marco; Morresi, Assunta; Sassi, Paola

doi:10.1039/c9cp03451j

Cited by 8 publications

(9 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The C≡O antisymmetric stretching band of the membrane-solubilized W(CO) 6 presents two contributions, at 1981 cm −1 ( ν as1 (CO)) and 1975 cm − 1 ( ν as2 (CO)). The first vibrational mode, ν as1 (CO), is attributed to W(CO) 6 molecules solubilized close to the center of the membrane, i.e., deep inside the hydrophobic core of the membrane, whereas ν as2 (CO) arises from W(CO) 6 in proximity to the ester groups in the interfacial region of the bilayer ( 51 , 52 ). The first component, ν as1 (CO), is narrower because of the fact that the probe is surrounded by long hydrocarbon chains that provide a homogeneous environment.…”

Section: Resultsmentioning

confidence: 99%

Effect of DMSO on the Mechanical and Structural Properties of Model and Biological Membranes

Gironi

Kahveci

McGill

et al. 2020

Biophysical Journal

Self Cite

View full text Add to dashboard Cite

Dimethyl sulfoxide (DMSO) is widely used in a number of biological and biotechnological applications, mainly because of its effects on the cell plasma membrane, but the molecular origins of this action are yet to be fully clarified. In this work, we used two-and three-component synthetic membranes (liposomes) and the plasma membrane of human erythrocytes to investigate the effect of DMSO when added to the membrane-solvating environment. Fourier transform infrared spectroscopy and thermal fluctuation spectroscopy revealed significant differences in the response of the two types of liposome systems to DMSO in terms of the bilayer thermotropic behavior, available free volume of the bilayer, its excess surface area, and bending elasticity. DMSO also alters the mechanical properties of the erythrocyte membrane in a concentration-dependent manner and is capable of increasing membrane permeability to ATP at even relatively low concentrations (3% v/v and above). Taken in its entirety, these results show that DMSO is likely to have a differential effect on heterogeneous biological membranes, depending on their local composition and structure, and could affect membrane-hosted biological functions.

show abstract

Section: Resultsmentioning

confidence: 99%

Effect of DMSO on the Mechanical and Structural Properties of Model and Biological Membranes

Gironi

Kahveci

McGill

et al. 2020

Biophysical Journal

Self Cite

View full text Add to dashboard Cite

show abstract

“…The FTIR spectra of the nonionic solute (W(CO) 6 ) in the region of the CO asymmetric stretch (Figure c) reveal two bands with a main band located at ∼1980 cm –1 and a side band at ∼2020 cm –1 . The main band, which has been previously assigned to the CO asymmetric stretch, − has a slight asymmetric line shape in all studied solvents, with its features being almost identical to those in DES2 and DES4 but slightly different in NMA as seen in its fwhm (see the Supporting Information). The CO asymmetric stretch is broader in NMA compared to those in DES2 and DES4, which is opposite to the trend presented by the other two solutes.…”

Section: Resultsmentioning

confidence: 58%

“…The selected solutes (Scheme ) are tetrabutylammonium thiocyanate (TBASCN), benzyl thiocyanate (BSCN), and tungsten hexacarbonyl (W(CO) 6 ). The selection of these solutes is based on each having vibrational modes with sensitivity to structural and dynamical changes in the molecular environment. − In particular, the thiocyanate ion (SCN – ) has been extensively used as an infrared probe in a variety of different systems, such as molecular solvents and ionic liquids. − , Moreover, it has been previously demonstrated that the tetrabutylammonium cation (TBA + ) causes negligible perturbation to the solvation of the thiocyanate ion . In the case of BSCN, generally organic thiocyanates are shown to be good infrared probes to study solvent dynamics and site-specific changes at interfaces. , Finally, W(CO) 6 has been successfully utilized to probe the structure of nonpolar domains, such as those found in bilayers. − The IR active mode of CO stretch was previously shown to be a triply degenerate (T 1u ), vibrationally coupled, and delocalized mode, which is referred to as CO asymmetric stretch in this work. , In addition, the nearby Raman active mode of CO stretch is a doubly degenerate mode with E g symmetry, which is referred to as CO symmetric stretch here. , Moreover, the vibrational dynamics, energy relaxation, and intra-/intermolecular energy transfer of the CO asymmetric stretch mode of W(CO) 6 was previously characterized via ultrafast IR spectroscopy …”

Section: Introductionmentioning

confidence: 99%

Assessing the Location of Ionic and Molecular Solutes in a Molecularly Heterogeneous and Nonionic Deep Eutectic Solvent

et al. 2020

View full text Add to dashboard Cite

Deep eutectic solvents (DES) are emerging sustainable designer solvents viewed as greener and better alternatives to ionic liquids. Nonionic DESs possess unique properties such as viscosity and hydrophobicity that make them desirable in microextraction applications such as oil-spill remediation. This work builds upon a nonionic DES, NMA–LA DES, previously designed by our group. The NMA–LA DES presents a rich nanoscopic morphology that could be used to allocate solutes of different polarities. In this work, the possibility of solvating different solutes within the nanoscopically heterogeneous molecular structure of the NMA–LA DES is investigated using ionic and molecular solutes. In particular, the localized vibrational transitions in these solutes are used as reporters of the DES molecular structure via vibrational spectroscopy. The FTIR and 2DIR data suggest that the ionic solute is confined in a polar and continuous domain formed by NMA, clearly sensing the direct effect of the change in NMA concentration. In the case of the molecular nonionic and polar solute, the data indicates that the solute resides in the interface between the polar and nonpolar domains. Finally, the results for the nonpolar and nonionic solute (W(CO)6) are unexpected and less conclusive. Contrary to its polarity, the data suggest that the W(CO)6 resides within the NMA polar domain of the DES, probably by inducing a domain restructuring in the solvent. However, the data are not conclusive enough to discard the possibility that the restructuring comprises not only the polar domain but also the interface. Overall, our results demonstrate that the NMA–LA DES has nanoscopic domains with affinity to particular molecular properties, such as polarity. Thus, the presented results have a direct implication to separation science.

show abstract

“…However, in the present case, bands are at least three times larger than the resolution limit. In other cases, when the infrared bands are narrower [11], a narrower spectral range is achieved by utilising a more dispersive grating.…”

Section: Instrumental Setupmentioning

confidence: 99%

“…In the last decades non-linear infrared spectroscopy like bidimensional infrared (2DIR) spectroscopy [5,6] has been largely exploited in the structural dynamic characterization of several molecular systems of increasing complexity. Particular attention has been devoted to the study of peptides [7][8][9][10][11][12] thanks to the large sensitivity of the CO stretching mode around 6 μm wavelength. The high localization of this mode makes it a good probe for molecular conformation analysis.…”

Section: Introductionmentioning

confidence: 99%

Linear and Non-Linear Middle Infrared Spectra of Penicillin G in the CO Stretching Mode Region

Ragnoni¹,

Catalini²,

Becucci

et al. 2021

Symmetry

Self Cite

View full text Add to dashboard Cite

In this work we report the linear and non-linear IR spectral response characterization of the CO bonds of PenicillinG sodium salt in D2O and in DMSO−d6 solutions. In order to better characterize the spectral IR features in the CO stretching region, broadband middle infrared pump-probe spectra are recorded. The role of hydrogen bonds in determining the inhomogeneous broadening and in tuning anharmonicity of the different types of oscillators is exploited. Narrow band pump experiments, at the three central frequencies of β−lactam, amide and carboxylate CO stretching modes, identify the couplings between the different types of CO oscillators opening the possibility to gather structural dynamic information. Our results show that the strongest coupling is between the β−lactam and the carboxylate CO vibrational modes.

show abstract

Free volume and dynamics in a lipid bilayer

Abstract: The free volume distribution and the picosecond dynamics inside a model lipid membrane are explored in a wide temperature range and at different solvating conditions.

Cited by 8 publications

References 35 publications

Effect of DMSO on the Mechanical and Structural Properties of Model and Biological Membranes

Effect of DMSO on the Mechanical and Structural Properties of Model and Biological Membranes

Assessing the Location of Ionic and Molecular Solutes in a Molecularly Heterogeneous and Nonionic Deep Eutectic Solvent

Linear and Non-Linear Middle Infrared Spectra of Penicillin G in the CO Stretching Mode Region

Contact Info

Product

Resources

About