89616-05-7Relevant academic research and scientific papers
Effect of the Binding Sites of Human Serum Albumin on the Efficiency and Photostationary State Isomer Ratios of the Photoisomerization of Bilirubin
Kanna, Yoko,Arai, Tatsuo,Tokumaru, Katsumi
, p. 2758 - 2762 (2007/10/02)
The quantum yields of the isomerization and photostationary state isomer ratios of the photoisomerization of (4Z,15Z)-bilirubin IXα (ZZ-BR) were determined in an aqueous buffered solution in the presence of human serum albumin (HSA) at a molar ratio of / from 0.5 to 2.The BR isomer compositions in the photostationary state were constant at /=0.5-0.7.With increasing / from 0.8 to 2, the ZZ-BR composition in the photostationary state increased from 58 to 75percent, but the ZE-BR composition decreased from 39 to 22percent.The quantum yields in the isomerization of ZZ-BR to ZE-BR (ΦZZ->ZE) and a cyclized product, lumirubin (LR), (ΦZZ->LR), remained unvaried up to /=1, but ΦZZ->ZE decreased while ΦZZ->LR increased along with a further increase of /.These results are explained by the existence of two binding sites, a first-class site and a second-class site, for bilirubin binding to HSA; ΦZZ->ZE in the second-class site (=0.035) was as low as 1/3 of that in the first-class site (=0.11), but ΦZZ->LR in the second-class site (=4.2*10-3) was nearly two-times higher than that in the first-class site (=2.4*10-3).
Photoisomerization of Bilirubins and the Role of Intramolecular Hydrogen Bonds
Kanna, Yoko,Arai, Tatsuo,Tokumaru, Katsumi
, p. 1482 - 1489 (2007/10/02)
The quantum yields and the photostationary state isomer in the photoisomerization of bilirubin are strongly governed by the properties of the reaction media.Among the reaction media examined, the quantum yields for ZZ->ZE isomerization (φZZ-ZE) and for cyclization (φLR) were the highest in buffered aqueous solution (potassium phosphate buffer, pH 7.4) containing human serum albumin (HSA) in a 1:1 molar ratio to ZZ-BR, 0.11 and 2*10-3, respectively, on 436 nm irradiation.The effects of the reaction media surrounding bilirubin are discussed.
Effect of Serum Albumins from Several Mammals on the Photoisomerization of Bilirubin
Kanna, Yoko,Arai, Tatsuo,Tokumaru, Katsumi
, p. 1586 - 1588 (2007/10/02)
ZZ-Bilirubin undergoes photoisomerization to configurational (ZE and EZ isomers) and structural (LR) isomers in buffered aqueous solution containing serum albumins.The efficiency and the course of the isomerization are very much dependent on the mammals from which serum albumins are taken.
Effects of Solvents and Media on the Efficiency and Course of Photoisomerization of Bilirubins
Kanna, Yoko,Arai, Tatsuo,Sakuragi, Hirochika,Tokumaru, Katsumi
, p. 631 - 634 (2007/10/02)
The quantum yields of photoisomerization of bilirubin to various isomers were determined in various solvents.A specific photoisomerization took place only in buffered solutions containing human serum albumin.We discuss the effects of solvents and media surrounding bilirubin on its photoisomerization.
Human Serum Albumin as a Chiral Template. Stereoselective Photocyclization of Bilirubin
McDonagh, Antony F.,Lightner, David A.,Reisinger, Michael,Palma, Lucita A.
, p. 249 - 250 (2007/10/02)
Bilirubin (1) bound to human serum albumin undergoes an asymmetric photocyclization to give optically active (2), which exhibits bisignate long-wavelength circular dichroism.
