title: Photophysical and photochemical studies of chlorophyll a and cobalt(II)tetraphenylporphyrin in poly(L-glutamate)-decylammonium ion complex.
abstract: Spectroscopic studies were carried out on chlorophyll a and cobalt(II)tetraphenylporphyrin solubilized in a poly(L-glutamate) (Poly(Glu))-decylammonium chloride (DeAC) complex system, in the presence of methylviologen (MV2+). The cooperative binding occurred between the anionic Poly(Glu) and the cationic DeAC, leading to the formation of micelle-like hydrophobic clusters of DeAC and also the change in conformation of the Poly(Glu) from the random coil to the alpha-helix. All of the absorption spectra, the fluorescence quantum yields and the fluorescence lifetimes indicated the existence of equilibrium between the aggregated biofunctional molecules in the bulk phase and the monomeric species in the complex phase of the Poly(Glu)-DeAC solution. The fluorescence quenching of the biofunctional molecules by methylviologen indicates that the conformation-dependent electron transfer occurs in the complex phase.
authors.affiliation: Department of Chemistry and Bioscience, Faculty of Science, Kagoshima University, 1-21-35 Korimoto, Kagoshima 890-0065, Japan.
authors.forename: Pascaline
authors.initials: P
authors.lastname: Ngweniform
authors.forename: Yoshihumi
authors.initials: Y
authors.lastname: Kusumoto
authors.forename: Miyuki
authors.initials: M
authors.lastname: Ikeda
authors.forename: Shouichi
authors.initials: S
authors.lastname: Somekawa
authors.forename: Bashir
authors.initials: B
authors.lastname: Ahmmad
authors.forename: Junichi
authors.initials: J
authors.lastname: Kurawaki
authors.forename: Katumitu
authors.initials: K
authors.lastname: Hayakawa
mesh_terms: D000588:Amines / Q000737:chemistry; D002734:Chlorophyll / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D007477:Ions; D008823:Micelles; D008968:Molecular Conformation; D010777:Photochemistry; D011099:Polyglutamic Acid / Q000737:chemistry; D011166:Porphyrins / Q000737:chemistry*; D013057:Spectrum Analysis
chemical_list: D000588:Amines; D007477:Ions; D008823:Micelles; D011166:Porphyrins; C409084:tetraphenylporphyrin; D002734:Chlorophyll; D011099:Polyglutamic Acid; D003035:Cobalt; C004744:decylamine