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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Oxygen distribution in the fluid/gel phases of lipid membranes

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Bacellar, Isabel O. L. [1, 2] ; Cordeiro, Rodrigo M. [3] ; Mahling, Pascal [2] ; Baptista, Mauricio S. [1] ; Roeder, Beate [2] ; Hackbarth, Steffen [2]
Total Authors: 6
[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
Total Affiliations: 3
Document type: Journal article
Source: BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES; v. 1861, n. 4, p. 879-886, APR 1 2019.
Web of Science Citations: 1

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)

FAPESP's process: 13/07937-8 - Redoxome - Redox Processes in Biomedicine
Grantee:Ohara Augusto
Support type: Research Grants - Research, Innovation and Dissemination Centers - RIDC
FAPESP's process: 13/11640-0 - Relationship between the photoinduced damage in lipids and membrane permeabilization
Grantee:Isabel de Oliveira Lima Bacellar
Support type: Scholarships in Brazil - Doctorate (Direct)
FAPESP's process: 12/50680-5 - Photosensitization in life sciences
Grantee:Mauricio da Silva Baptista
Support type: Research Projects - Thematic Grants