Oxygen distribution in the fluid/gel phases of lipid membranes

Autor(es)

Bacellar, Isabel O. L. ^{[1, 2]} ; Cordeiro, Rodrigo M. ^[3] ; Mahling, Pascal ^[2] ; Baptista, Mauricio S. ^[1] ; Roeder, Beate ^[2] ; Hackbarth, Steffen ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Quim, Dept Bioquim, Ave Prof Lineu Prestes 748, BR-05508900 Sao Paulo, SP - Brazil

^[2] Humboldt Univ, Inst Phys, Newtonstr 15, D-12489 Berlin - Germany

^[3] Univ Fed ABC, Ctr Ciencias Nat & Humanas, Ave Estados 5001, BR-09210580 Santo Andre, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES; v. 1861, n. 4, p. 879-886, APR 1 2019.
• Citações Web of Science: 5

Resumo

The interactions between oxygen and lipid membranes play fundamental roles in basic biological processes (e.g., cellular respiration). Obviously, membrane oxidation is expected to be critically dependent on the distribution and concentration of oxygen in the membrane. Here, we combined theoretical and experimental methods to investigate oxygen partition and distribution in lipid membranes of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) in a temperature range between 298 and 323 K, specifically focusing on the changes caused by the lipid phase and phase transition. Even though oxygen is known to be more concentrated in the center of fluid phase membranes than on the headgroup regions, the distribution profile of oxygen inside gel-phase bilayers remained to be determined. Molecular dynamics simulations now show that the distribution of oxygen inside DPPC bilayers dramatically changes upon crossing the main transition temperature, with oxygen being nearly depleted halfway from the headgroups to the membrane center below the transition temperature. In a parallel approach, singlet oxygen luminescence emission measurements employing the photosensitizer Pheophorbide-a (Pheo) confirmed the differences in oxygen distribution and concentration profiles between gel- and fluid-phase membranes, revealing changes in the micro environment of the embedded photosensitizer. Our results also reveal that excited triplet state lifetime, as it can be determined from the singlet oxygen luminescence kinetics, is a useful probe to assess oxygen distribution in lipid membranes with distinct lipid compositions. (AU)

• Processo FAPESP: 13/11640-0 - Relação entre o dano fotoinduzido em lipídeos e a permeabilização de membranas
• Beneficiário: Isabel de Oliveira Lima Bacellar
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto
• Processo FAPESP: 13/07937-8 - Redoxoma
• Beneficiário: Ohara Augusto
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs
• Processo FAPESP: 12/50680-5 - Fotossensibilização nas ciências da vida
• Beneficiário: Mauricio da Silva Baptista
• Modalidade de apoio: Auxílio à Pesquisa - Temático