Ferrous ion release from ferritin by ultraviolet-A radiations.
Ferritin is the principal protein of iron storage (in the Fe(III) state). The UV-A irradiation of 0.25 microM ferritin solutions (from horse spleen) loaded with 530 microM Fe(III) induces Fe2+ release in the medium. The initial quantum yield is wavelength dependent (phi(365 nm) approximately 2 x 10(-3) but pH and oxygen independent. The Fe2+ release reaches a plateau which strongly depends on pH and oxygen. The amino acid composition of the apoprotein is not altered by the UV irradiation. Addition of formate ions enhances the Fe2+ production, suggesting that the ferritin photoreduction involves an electron transfer from an OH- ligand. The possible importance of this phenomenon in skin photobiology is discussed.
Aubailly
M
M
Muséum National d'Histoire Naturelle, Laboratoire de Physico-Chimie de l'Adaptation Biologique, (INSERM U.312), Paris, France.
Santus
R
R
Salmon
S
S
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001052:Apoferritins / Q000737:chemistry; D004307:Dose-Response Relationship, Radiation; D005290:Ferric Compounds / Q000528:radiation effects; D005293:Ferritins / Q000737:chemistry / Q000528:radiation effects*; D005561:Formates / Q000737:chemistry; D006736:Horses; D006863:Hydrogen-Ion Concentration; D007477:Ions; D007501:Iron / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet; D014466:Ultraviolet Rays / Q000009:adverse effects*
D000596:Amino Acids; D005290:Ferric Compounds; D005561:Formates; D007477:Ions; D005293:Ferritins; D001052:Apoferritins; D007501:Iron; D010100:Oxygen