title: Optimization and characterization of the endogenous production of protoporphyrin IX in a yeast model.
abstract: The availability of reproducible, convenient, and inexpensive model organisms able to generate predictable levels of endogenous porphyrins, including protoporphyrin IX (PpIX), is essential in photomedicine research. Saccharomyces cerevisiae produces endogenous PpIX and was used as a model organism for this study with the aim to maximize endogenous PpIX fluorescence intensity. It was found that PpIX fluorescence was significantly enhanced by administration of 5-aminolevulinic acid (ALA) and 2,2?-bipyridyl. Fluorescence intensity and spectroscopy of PpIX produced endogenously were measured in diluted yeast solutions under various conditions. The optimal protocol was: 5 ?? ? M ALA and 1 mM 2,2?-bipyridyl administered synchronously at 32°C. After 3 h, PpIX in yeast demonstrated similar steady-state and time-resolved spectroscopy as that of PpIX in DMSO. Moreover, under hypoxic conditions, the reciprocal lifetime of PpIX delayed fluorescence measured in real time was correlated to the partial pressure of oxygen ( pO 2 ) measured concomitantly with a commercially available pO 2 probe. These data show that yeast can, in optimal conditions, reproducibly generate PpIX. This is of interest in various fields such as photodiagnosis, photodynamic therapy, and photobiomodulation. Use of this model organism focuses on essential mechanisms, without the complexity of a multicellular organism.
authors.affiliation: Swiss Federal Institute of Technology (EPFL), Laboratory of Organometallic and Medicinal Chemistry, ISIC, BCH 2402 (Batochime), CH-1015 Lausanne, Switzerland.
authors.forename: Jaroslava
authors.initials: J
authors.lastname: Joniová
authors.affiliation: Swiss Federal Institute of Technology (EPFL), Laboratory of Organometallic and Medicinal Chemistry, ISIC, BCH 2402 (Batochime), CH-1015 Lausanne, Switzerland.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Gerelli
authors.affiliation: Swiss Federal Institute of Technology (EPFL), Laboratory of Organometallic and Medicinal Chemistry, ISIC, BCH 2402 (Batochime), CH-1015 Lausanne, Switzerland.
authors.forename: Matthieu
authors.initials: M
authors.lastname: Zellweger
authors.affiliation: Swiss Federal Institute of Technology (EPFL), Laboratory of Organometallic and Medicinal Chemistry, ISIC, BCH 2402 (Batochime), CH-1015 Lausanne, Switzerland.
authors.forename: Georges
authors.initials: G
authors.lastname: Wagnières
mesh_terms: D000622:Aminolevulinic Acid / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D008954:Models, Biological; D010100:Oxygen / Q000378:metabolism; D011524:Protoporphyrins / Q000032:analysis / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D013050:Spectrometry, Fluorescence / Q000379:methods*
chemical_list: D011524:Protoporphyrins; D000622:Aminolevulinic Acid; C028025:protoporphyrin IX; D005947:Glucose; D010100:Oxygen