Impact of sphingomyelin acyl chain (16:0 vs 24:1) on the interfacial properties of Langmuir monolayers: A PM-IRRAS study.

Autor: Vázquez RF; Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), CCT- La Plata, CONICET, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, 60 y 120, (1900), La Plata, Argentina; Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, 47 y 115, (1900), La Plata, Argentina., Daza Millone MA; Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), CCT- La Plata, CONICET, Universidad Nacional de La Plata, Sucursal 4 Casilla de Correo 16, (1900), La Plata, Argentina., Pavinatto FJ; São Carlos Institute of Physics, University of São Paulo, SP, Brazil., Fanani ML; Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), CONICET, Argentina; Departamento de Química Biológica Ranwel Caputto, Facultad de Cs. Químicas, Universidad Nacional de Córdoba. Haya de la Torre y Medina Allende, Ciudad Universitaria, Córdoba, Argentina., Oliveira ON Jr; São Carlos Institute of Physics, University of São Paulo, SP, Brazil., Vela ME; Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), CCT- La Plata, CONICET, Universidad Nacional de La Plata, Sucursal 4 Casilla de Correo 16, (1900), La Plata, Argentina., Maté SM; Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), CCT- La Plata, CONICET, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, 60 y 120, (1900), La Plata, Argentina. Electronic address: smate@med.unlp.edu.ar.
Jazyk: angličtina
Zdroj: Colloids and surfaces. B, Biointerfaces [Colloids Surf B Biointerfaces] 2019 Jan 01; Vol. 173, pp. 549-556. Date of Electronic Publication: 2018 Oct 11.
DOI: 10.1016/j.colsurfb.2018.10.018
Abstrakt: Membrane structure is a key factor for the cell`s physiology, pathology, and therapy. Evaluating the importance of lipid species such as N-nervonoyl sphingomyelin (24:1-SM) -able to prevent phase separation- to membrane structuring remains a formidable challenge. This is the first report in which polarization-modulated infrared reflection-absorption spectroscopy (PM-IRRAS) is applied to investigate the lipid-lipid interactions in 16:0 vs 24:1-SM monolayers and their mixtures with 1,2-Dioleoyl-sn-glycero-3-phosphocholine (DOPC) and cholesterol (Chol) (DOPC/SM/Chol 2:1:1). From the results we inferred that the cis double bond (Δ15) in 24:1-SM molecule diminishes intermolecular H-bonding and chain packing density compared to that of 16:0-SM. In ternary mixtures containing 16:0-SM, the relative intensity of the two components of the Amide I band reflected changes in the H-bonding network due to SM-Chol interactions. In contrast, the contribution of the main components of the Amide I band in DOPC/24:1-SM/Chol remained as in 24:1-SM monolayers, with a larger contribution of the non-H-bonded component. The most interesting feature in these ternary films is that the CO stretching mode of DOPC appeared with an intensity similar to that of SM Amide I band in DOPC/16:0-SM/Chol monolayers (a two-phase [Lo/Le] system), whereas an extremely low intensity of the CO band was detected in DOPC/24:1-SM/Chol monolayers (single Le phase). This is evidence that the unsaturation in 24:1-SM affected not only the conformational properties of acyl chains but also the orientation of the chemical groups at the air/water interface. The physical properties and overall H-bonding ability conferred by 24:1-SM may have implications in cell signaling and binding of biomolecules.
(Copyright © 2018 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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