Effects of the micro-environment on the photophysical properties of hematoporphyrin

VanSteveninck, John; Lagerberg, Johan W.M.; Charlesworth, Paul; Dubbelman, T. M. A. R.; Truscott, T. G.

doi:10.1016/0304-4165(94)90146-5

Cited by 3 publications

(1 citation statement)

References 17 publications

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“…1 A. The main spectral characteristics of PE-porph are quite similar to those observed for porphyrin incorporated in model membranes (21,22), with the maximum absorption at~400 nm and the emission above 600 nm (see Fig. 1 B).…”

Section: Characterization Of the Photosensitive Molecule Pe-porphsupporting

confidence: 69%

Giant Vesicles under Oxidative Stress Induced by a Membrane-Anchored Photosensitizer

Riske

Sudbrack

Archilha

et al. 2009

Biophysical Journal

131

133

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We have synthesized the amphiphile photosensitizer PE-porph consisting of a porphyrin bound to a lipid headgroup. We studied by optical microscopy the response to light irradiation of giant unilamellar vesicles of mixtures of unsaturated phosphatidylcholine lipids and PE-porph. In this configuration, singlet oxygen is produced at the bilayer surface by the anchored porphyrin. Under irradiation, the PE-porph decorated giant unilamellar vesicles exhibit a rapid increase in surface area with concomitant morphological changes. We quantify the surface area increase of the bilayers as a function of time and photosensitizer molar fraction. We attribute this expansion to hydroperoxide formation by the reaction of the singlet oxygen with the unsaturated bonds. Considering data from numeric simulations of relative area increase per phospholipid oxidized (15%), we measure the efficiency of the oxidative reactions. We conclude that for every 270 singlet oxygen molecules produced by the layer of anchored porphyrins, one eventually reacts to generate a hydroperoxide species. Remarkably, the integrity of the membrane is preserved in the full experimental range explored here, up to a hydroperoxide content of 60%, inducing an 8% relative area expansion.

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Section: Characterization Of the Photosensitive Molecule Pe-porphsupporting

confidence: 69%