Impact of sphingomyelin acyl chain (16:0 vs 24:1) on the interfacial properties of Langmuir monolayers: A PM-IRRAS study
| Autor: | Sabina María Maté, Romina Florencia Vázquez, M. Antonieta Daza Millone, Felippe José Pavinatto, María Elena Vela, Maria Laura Fanani, Osvaldo N. Oliveira |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Bioquímica
Double bond Membrane rafts 02 engineering and technology 01 natural sciences Ciencias Biológicas purl.org/becyt/ford/1 [https] Colloid and Surface Chemistry Phase (matter) 0103 physical sciences Monolayer Cholesterol-sphingomyelin interactions Molecule Physical and Theoretical Chemistry purl.org/becyt/ford/1.6 [https] Unilamellar Liposomes Langmuir monolayers chemistry.chemical_classification Degree of unsaturation Spectroscopy Near-Infrared 010304 chemical physics Chemistry Membrane structure Hydrogen Bonding Surfaces and Interfaces General Medicine 021001 nanoscience & nanotechnology Biofísica Sphingomyelins PM-IRRAS Crystallography Cholesterol Membrane Phosphatidylcholines MICROSCOPIA 0210 nano-technology Sphingomyelin CIENCIAS NATURALES Y EXACTAS Biotechnology |
| Zdroj: | SEDICI (UNLP) Universidad Nacional de La Plata instacron:UNLP Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP CONICET Digital (CONICET) Consejo Nacional de Investigaciones Científicas y Técnicas instacron:CONICET |
| Popis: | 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. Instituto de Investigaciones Bioquímicas de La Plata Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas |
| Databáze: | OpenAIRE |
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