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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.)

Not Only Oxidation of Cardiolipin Affects the Affinity of Cytochrome c for Lipid Bilayers

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Author(s):
Kawai, Cintia [1, 2] ; Ferreira, Juliana C. [3] ; Baptista, Mauricio S. [2] ; Nantes, Iseli L. [1]
Total Authors: 4
Affiliation:
[1] Univ Fed ABC, Ctr Ciencias Nat & Humanas, BR-09210580 Santo Andre, SP - Brazil
[2] Univ Sao Paulo, Inst Quim, Dept Bioquim, BR-05508900 Sao Paulo - Brazil
[3] Univ Fed Sao Paulo, Dept Biofis, BR-04021001 Sao Paulo - Brazil
Total Affiliations: 3
Document type: Journal article
Source: Journal of Physical Chemistry B; v. 118, n. 41, p. 11863-11872, OCT 16 2014.
Web of Science Citations: 10
Abstract

Fluorescence quenching of lipid-bound pyrene was used to assess the binding of cytochrome c (cyt c) to liposomes that mimic the inner mitochondrial membrane (IMM) POPC/DOPE/TOCL, with the conditions that it did or did not contain oxidized phosphatidylcholine molecules, i.e., 1-O-hexadecyl-2-azelaoyl-sn-glycero-3-phosphocholine (PazePC), or a mixture of two hydroperoxide isomers derived from POPC (POPCOX). The binding isotherms reveal two dissociation constants, KD(1) and KD(2), representing, respectively, the low- and high-affinity states of the membrane. These dissociation constants probably are due to the lipid reorganization promoted by cyt c, as observed in giant unilamellar vesicles that contain fluorescent cardiolipin (CL). The presence of PazePC, which has a nonreactive carboxylic group, increased the KD(1) and KD(2) values 1.2- and 4.5-fold, respectively. The presence of POPCOX which has a reactive peroxide group, decreased the KD(1) value 1.5-fold, increased the KD(2) value 10-fold, and significantly reduced the salt-induced detachment of cyt c. MALDI-TOF spectrometry analysis of cyt c incubated with liposomes containing POPCox demonstrated a mass increase corresponding to the formation of nonenal adducts as hydrophobic anchors. Electronic absorption spectroscopy, circular dichroism, and magnetic circular dichroism demonstrated that all of the lipids studied promoted changes in the cyt c coordination sphere. Therefore, in the presence of CL, the oxidation of zwitterionic lipids also promotes changes in the cyt c structure and in the affinity for lipid bilayers. (AU)

FAPESP's process: 12/12663-1 - Singlet molecular oxygen and peroxides in chemical biology
Grantee:Paolo Di Mascio
Support type: Research Projects - Thematic Grants
FAPESP's process: 12/07456-7 - Flow cytometry studies of cell death and protection promoted by porphyrinoid compounds, phenothiazines and Teluranes associated to nanostructures in a cell biology multiuser lab
Grantee:Iseli Lourenço Nantes Cardoso
Support type: Regular Research Grants
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: 12/50680-5 - Photosensitization in life sciences
Grantee:Mauricio da Silva Baptista
Support type: Research Projects - Thematic Grants