Photosensitized damage of protein by fluorinated diethoxyphosphorus(V)porphyrin

2013 ◽  
Vol 17 (01n02) ◽  
pp. 56-62 ◽  
Author(s):  
Kazutaka Hirakawa ◽  
Keito Azumi ◽  
Yoshinobu Nishimura ◽  
Tatsuo Arai ◽  
Yoshio Nosaka ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Human Serum Albumin ◽  
Serum Albumin ◽  
Singlet Oxygen ◽  
Human Serum ◽  
Transfer Mechanism ◽  
Water Soluble ◽  
Electron Transfer Mechanism ◽  
Oxygen Generation ◽  
Singlet Oxygen Generation

The effect of the axial ligand fluorination of the water-soluble P(V)porphyrin complex on photosensitized protein damage was examined. The activity of singlet oxygen generation by diethoxyP(V) porphyrin was slightly improved by the fluorination of the ethoxy chains. Absorption spectrum measurements demonstrated the binding interaction between the P(V)porphyrins and human serum albumin, a water-soluble protein. Photo-irradiated P(V)porphyrins damaged the amino acid residue of human serum albumin, resulting in the decrease of the fluorescence intensity from the tryptophan residue of human serum albumin. A singlet oxygen quencher, sodium azide, could not completely inhibit the damage of human serum albumin, suggesting that the electron transfer mechanism contributes to protein damage as does singlet oxygen generation. The decrease of the fluorescence lifetime of P(V)porphyrin by human serum albumin supported the electron transfer mechanism. The estimated contributions of the electron transfer mechanism are 0.57 and 0.44 for the fluorinated and non-fluorinated P(V)porphyrins, respectively. The total quantum yield of the protein photo-oxidation was slightly enhanced by this axial fluorination.

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.

Singlet oxygen generation by sonication using a water-soluble fullerene (C60) complex: a potential application for sonodynamic therapy

2020 ◽  
Vol 52 (12) ◽  
pp. 1387-1394
Author(s):  
Thi Lien Nguyen ◽  
Risa Katayama ◽  
Chie Kojima ◽  
Akikazu Matsumoto ◽  
Kazuhiko Ishihara ◽  
...  
Keyword(s):  
Singlet Oxygen ◽  
Potential Application ◽  
Fullerene C60 ◽  
Water Soluble ◽  
Sonodynamic Therapy ◽  
Oxygen Generation ◽  
Singlet Oxygen Generation

In vitro assay of singlet oxygen generation in the presence of water-soluble derivatives of C60

Carbon ◽  
2004 ◽  
Vol 42 (5-6) ◽  
pp. 1195-1198 ◽  
Author(s):  
Bertrand Vileno ◽  
Andrzej Sienkiewicz ◽  
Małgorzata Lekka ◽  
Andrzej J. Kulik ◽  
László Forró
Keyword(s):  
Singlet Oxygen ◽  
In Vitro Assay ◽  
Water Soluble ◽  
Vitro Assay ◽  
Oxygen Generation ◽  
Singlet Oxygen Generation ◽  
Derivatives Of

Effect of aggregation of a cationic phthalocyanine in micelles and in the presence of human serum albumin

2006 ◽  
Vol 10 (01) ◽  
pp. 33-42 ◽  
Author(s):  
Myriam E. Rodriguez ◽  
Daniel A. Fernández ◽  
Josefina Awruch ◽  
Silvia E. Braslavsky ◽  
Lelia E. Dicelio
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Hydrophobic Interactions ◽  
Photophysical Properties ◽  
Sodium Dodecylsulfate ◽  
Water Soluble ◽  
Quantum Yields ◽  
Ionic Interactions ◽  
Triplet Quantum Yields

The photophysical properties of tetrakis(1,1-dimethyl-2-trimethylammonium)ethylphthalocyaninato zinc(II) tetraiodide (I) – a water-soluble cationic phthalocyanine – are presented in the presence of human serum albumin (HSA) and in micelles of sodium dodecylsulfate ( SDS ) and hexadecyltrimethylammonium chloride ( CTAC ). Spectrophotometric measurements showed that the surfactants SDS and CTAC induce monomerization of I, although the latter less efficiently than the former. This effect is less pronounced in the presence of HSA. The strength of this effect is evaluated through dimerization constants, which are Kd = (5 ± 1) × 105 m−1 in SDS , (1.5 ± 0.5) × 106 M −1 in CTAC , and (1.8 ± 0.9) × 106 M −1 in HSA. Fluorescence experiments confirm that aggregation of I drops as the concentration of surfactant is raised. Triplet quantum yields also decreased upon aggregation and were Φ T = 0.59, 0.16, and < 0.01 in SDS , CTAC , and HSA, respectively. These results indicate that the affinity of I for the environment is not just due to ionic interactions; hydrophobic interactions play an equally important role.

scholarly journals Lysine residue 240 of human serum albumin is involved in high-affinity binding of bilirubin

1978 ◽  
Vol 171 (2) ◽  
pp. 453-459 ◽  
Author(s):  
C Jacobsen
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Lysine Residue ◽  
Water Soluble ◽  
High Affinity ◽  
Coupling Reagent ◽  
Peptide Fraction ◽  
Short Period ◽  
High Affinity Site

Bilirubin can be coupled covalently to albumin by using water-soluble carbodi-imide as coupling reagent. The optimal specificity in the attachment of bilirubin to the high-affinity site on the albumin molecule was obtained by treating an albumin-bilirubin complex with carbodi-imide in low concentrations and for a short period. The product was reduced, carboxymethylated and digested with trypsin. By fractionation on Sephadex G-50 (superfine grade) a peptide fraction containing most of the bilirubin label was isolated. Further purification by paper chromatography gave one peptide, consisting of residues 240-258. The peptide containined a single lysine residue, 240, and had an intact disulphide bridge. The results indicate that bilirubin is bound to lysine residue 240 at its high-affinity site on human serum albumin.

Water-Soluble α,β-Unsaturated Aldehydes of Cigarette Smoke Induce Carbonylation of Human Serum Albumin

2010 ◽  
Vol 12 (3) ◽  
pp. 349-364 ◽  
Author(s):  
Graziano Colombo ◽  
Giancarlo Aldini ◽  
Marica Orioli ◽  
Daniela Giustarini ◽  
Rosalba Gornati ◽  
...  
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Cigarette Smoke ◽  
Water Soluble ◽  
Unsaturated Aldehydes
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