Document Type

Conference Proceeding

Publication Date

5-1-2005

Abstract

This study was designed to provide more detailed information on the subcellular sites of binding of the porphycene, termed 9-capronyloxytetrakis (methoxyethyl) porphycene (CPO), with a fluorescence resonance energy transfer (FRET) technique. The proximity of CPO to two fluorescent probes was determined: nonyl acridine orange (NAO), a dye with specific affinity for the mitochondrial lipid cardiolipin, and dihexaoxacarbocyanine iodide (DiOC 6), an agent that labels the endoplasmic reticulum (ER). FRET spectra indicated energy transfer between DiOC 6 and CPO but no significant transfer between NAO and CPO. These results confirm data obtained by fluorescence microscopy, suggesting a similar pattern of subcellular localization by CPO and DiOC 6 but not by CPO and NAO. However, when cells containing CPO were irradiated and then loaded with NAO, FRET between the two fluorophores was observed. Hence, a relocalization of CPO can occur during irradiation. These data provide an explanation for recent studies on CPO-catalyzed photodamage to both ER and mitochondrial Bcl-2. © 2005 American Society for Photobiology.

Publication Source (Journal or Book title)

Photochemistry and Photobiology

First Page

569

Last Page

572

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