Determination of Singlet Oxygen and Electron Transfer Mediated Mechanisms of Photosensitized Protein Damage by Phosphorus(V)porphyrins

2015 ◽  
Vol 28 (2) ◽  
pp. 262-267 ◽  
Author(s):  
Kazutaka Hirakawa ◽  
Hironobu Umemoto ◽  
Ryo Kikuchi ◽  
Hiroki Yamaguchi ◽  
Yoshinobu Nishimura ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Singlet Oxygen ◽  
Protein Damage

Tetrakis(N-methyl-p-pyridinio)porphyrin and its zinc complex can photosensitize damage of human serum albumin through electron transfer and singlet oxygen generation

2016 ◽  
Vol 20 (07) ◽  
pp. 813-821 ◽  
Author(s):  
Dongyan Ouyang ◽  
Shiori Inoue ◽  
Shigetoshi Okazaki ◽  
Kazutaka Hirakawa
Keyword(s):  
Electron Transfer ◽  
Human Serum Albumin ◽  
Serum Albumin ◽  
Singlet Oxygen ◽  
Human Serum ◽  
Sodium Azide ◽  
Zinc Complex ◽  
Transfer Mechanism ◽  
Protein Damage ◽  
Electron Transfer Mechanism

The photosensitized protein-damaging activity of water-soluble freebase tetrakis([Formula: see text]-methyl-[Formula: see text]-pyridinio)porphyrin (H2TMPyP), and its zinc complex (ZnTMPyP) was investigated using human serum albumin (HSA) as a target protein. These porphyrins bound to HSA and caused photosensitized oxidation of the tryptophan residue. The protein damage was enhanced in deuterium oxide and inhibited by sodium azide, a physical quencher of singlet oxygen, suggesting the contribution of singlet oxygen. However, an excess amount of sodium azide could not completely inhibit protein damage. These findings suggest the partial contribution of another mechanism to the protein damage, possibly the electron transfer mechanism. The Gibbs free energy of the electron transfer mechanism showed that electron transfer-mediated tryptophan oxidation by photoexcited H2TMPyP is more advantageous than that by ZnTMPyP. Actually, the quantum yield of protein damage through electron transfer by H2TMPyP was larger than that by ZnTMPyP. In addition, this study demonstrated that the association between porphyrin and protein plays an important role in photosensitized protein damage.

UV-Vis Spectrophotometrical and Analytical Methodology for the Determination of Singlet Oxygen in New Antibacterials Drugs

2007 ◽  
Vol 2 ◽  
pp. 117739010700200 ◽  
Author(s):  
Tamara Zoltan ◽  
Franklin Vargas ◽  
Carla Izzo
Keyword(s):  
Reactive Oxygen Species ◽  
Singlet Oxygen ◽  
Nalidixic Acid ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Inexpensive Method ◽  
Analytical Methodology ◽  
First Time

We have determined and quantified spectrophotometrically the capacity of producing reactive oxygen species (ROS) as 1O2 during the photolysis with UV-A light of 5 new synthesized naphthyl ester derivates of well-known quinolone antibacterials (nalidixic acid (1), cinoxacin (2), norfloxacin (3), ciprofloxacin (4) and enoxacin (5)). The ability of the naphthyl ester derivatives (6-10) to generate singlet oxygen were detecting and for the first time quantified by the histidine assay, a sensitive, fast and inexpensive method. The following tendency of generation of singlet oxygen was observed: compounds 7 >10 > 6 > 8 > 9 >> parent drugs 1-5.

Biosensor Based on TTF@ SiO2 Nanoparticles as Electron Transfer Mediator for the Determination of Glucose1

2006 ◽  
Vol 22 (4) ◽  
pp. 474-478 ◽  
Author(s):  
X LI ◽  
Y XIAN ◽  
H MIN ◽  
C LI ◽  
Z XIE ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Sio2 Nanoparticles ◽  
Electron Transfer Mediator

Novel anthracene- and pyridine-containing Schiff base probe for selective “off–on” fluorescent determination of Cu2+ ions towards live cell application

2016 ◽  
Vol 40 (7) ◽  
pp. 6101-6108 ◽  
Author(s):  
Turibius Simon ◽  
Muthaiah Shellaiah ◽  
Venkatesan Srinivasadesikan ◽  
Ching-Chang Lin ◽  
Fu-Hsiang Ko ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Schiff Base ◽  
Photoinduced Electron Transfer ◽  
Transfer Mechanism ◽  
Live Cell ◽  
Live Cells ◽  
Electron Transfer Mechanism

A simple anthracene-based AP probe was synthesized to detect Cu2+ ions, via the photoinduced electron transfer mechanism, in live cells.

Time-Resolved X-ray Absorption Determination of Structural Changes following Photoinduced Electron Transfer within Bis-porphyrin Heme Protein Models

1999 ◽  
Vol 103 (16) ◽  
pp. 3270-3274 ◽  
Author(s):  
Lin X. Chen ◽  
Peter L. Lee ◽  
David Gosztola ◽  
Walter A. Svec ◽  
Pedro A. Montano ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Photoinduced Electron Transfer ◽  
Structural Changes ◽  
Heme Protein ◽  
Time Resolved ◽  
X Ray ◽  
Absorption Determination ◽  
Protein Models ◽  
X Ray Absorption

Determination of the Structural Features of a Long-Lived Electron-Transfer State of 9-Mesityl-10-methylacridinium Ion

2012 ◽  
Vol 134 (10) ◽  
pp. 4569-4572 ◽  
Author(s):  
Manabu Hoshino ◽  
Hidehiro Uekusa ◽  
Ayana Tomita ◽  
Shin-ya Koshihara ◽  
Tokushi Sato ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Structural Features ◽  
Transfer State
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