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

Texto completo
Vazquez, Romina F. [1, 2] ; Daza Millone, Antonieta [3] ; Pavinatto, Felippe J. [4, 5] ; Fanani, Maria L. [6, 7] ; Oliveira, Jr., Osvaldo N. [5] ; Vela, Maria E. [3] ; Mate, Sabina M. [1]
Número total de Autores: 7
Afiliação do(s) autor(es):
[1] Univ Nacl La Plata, Inst Invest Bioquim La Plata INIBIOLP, CCT La Plata, CONICET, Fac Ciencias Med, RA-1900 La Plata, Buenos Aires - Argentina
[2] Univ Nacl La Plata, Dept Quim, Fac Ciencias Exactas, RA-1900 La Plata, Buenos Aires - Argentina
[3] Univ Nacl La Plata, Inst Invest Fisicoquim Teor & Aplicadas INIFTA, CCT La Plata, CONICET, Sucursal 4 Casilla Correo 16, RA-1900 La Plata, Buenos Aires - Argentina
[4] Univ Washington, Clean Energy Inst, Seattle, WA 98195 - USA
[5] Univ Sao Paulo, Sao Carlos Inst Phys, Sao Paulo, SP - Brazil
[6] Consejo Nacl Invest Cient & Tecn, Ctr Invest Quim Biol Cordoba CIQUIBIC, Buenos Aires, DF - Argentina
[7] Univ Nacl Cordoba, Dept Quim Biol Ranwel Caputto, Fac Cs Quim, Ciudad Univ, Cordoba - Argentina
Número total de Afiliações: 7
Tipo de documento: Artigo Científico
Fonte: COLLOIDS AND SURFACES B-BIOINTERFACES; v. 173, p. 549-556, JAN 1 2019.
Citações Web of Science: 0

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 (Delta 15) 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 C=O 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 C=0 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. (AU)

Processo FAPESP: 13/14262-7 - Filmes nanoestruturados de materiais de interesse biológico
Beneficiário:Osvaldo Novais de Oliveira Junior
Linha de fomento: Auxílio à Pesquisa - Temático