title: Structure, photophysical property, and cytotoxicity of human serum albumin complexed with tris(dicarboxymethylene)[60]fullerene.
abstract: We present structure, photoexcited triplet-state property, and singlet oxygen ((1)O 2) generation capability of human serum albumin complexed with a tris(dicarboxymethylene)[60]fullerene C3-isomer (HSA-CF). Small angle X-ray scattering measurements showed that a globular size-dimension and surface charge distribution of HSA were unaltered by monomolecular complexation of CF into the hydrophobic cavity. Laser flash photolysis to the HSA-CF solution yielded a photoexcited triplet state of the CF chromophore ((3)CF*) with lifetime of 46 mus. In the presence of O2, energy transfer occurred from HSA-(3)CF* to O2 to generate (1)O2; the quenching rate constant [k q(O2)] was determined to be 2.2 x 10 (8) M (-1) s (-1). The HSA-CF showed strong photoresistence relative to HSA complexed with a protoporphyrin IX. The quantum yield of (1)O2 production for this artificial protein was compared to those of other photosensitizing agent. The HSA-CF did not show a dark cytotoxicity, but induced cell death efficiently under visible light irradiation.
authors.affiliation: Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan.
authors.forename: Xue
authors.initials: X
authors.lastname: Qu
authors.forename: Teruyuki
authors.initials: T
authors.lastname: Komatsu
authors.forename: Takaaki
authors.initials: T
authors.lastname: Sato
authors.forename: Otto
authors.initials: O
authors.lastname: Glatter
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Horinouchi
authors.forename: Koichi
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Eishun
authors.initials: E
authors.lastname: Tsuchida
mesh_terms: D000818:Animals; D002417:Cattle; D016923:Cell Death / Q000187:drug effects; D045744:Cell Line, Tumor; D004735:Energy Transfer; D037741:Fullerenes / Q000737:chemistry* / Q000378:metabolism / Q000633:toxicity*; D006801:Humans; D008027:Light; D010100:Oxygen / Q000737:chemistry; D010777:Photochemistry; D017319:Photosensitizing Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000633:toxicity*; D012709:Serum Albumin / Q000737:chemistry* / Q000378:metabolism; D026082:Singlet Oxygen / Q000737:chemistry
chemical_list: D037741:Fullerenes; D017319:Photosensitizing Agents; D012709:Serum Albumin; C532332:tris(dicarboxymethylene)(60)fullerene; D026082:Singlet Oxygen; C069837:fullerene C60; D010100:Oxygen