Evidence for a slow and oxygen-insensitive intra-molecular long range electron transfer from tyrosine residues to the semi-oxidized tryptophan 214 in human serum albumin: its inhibition by bound copper (II)

Amino Acids ◽  
2010 ◽  
Vol 42 (4) ◽  
pp. 1269-1275 ◽  
Author(s):  
Larry K. Patterson ◽  
Jean-Claude Mazière ◽  
David M. Bartels ◽  
Gordon L. Hug ◽  
René Santus ◽  
...  
1979 ◽  
Vol 44 (5) ◽  
pp. 1657-1670 ◽  
Author(s):  
Ladislav Morávek ◽  
Mohamed Ali Saber ◽  
Bedřich Meloun

Human serum albumin was nitrated by an excess of tetranitromethane at pH 8.0. As shown by amino acid analysis, of the 18 tyrosine residues present in albumin about 7-7.5 residues remain unaltered, 9 residues are converted into 3-nitrotyrosine, and 1.2 residue into 3,5-dinitrotyrosine. The nitrated albumin was digested with cyanogen bromide to three fragments which comprise the whole original molecule. The individual fragments were converted into their S-sulfo derivatives and the latter digested with chymotrypsin or stepwise with trypsin and thermolysin. The yellow, nitrotyrosine-containing peptides were isolated from the digest and the positions of nitrated tyrosine residues in albumin thus located. Residues No 30, 148, 150, 161, 334, 341, 401, and 411 were identified as strongly nitrated and residues No 84, 138, 452, and 497 as medium nitrated. Residues No 140, 263, 319, 332, 353, and 367 either react weakly or were not found in nitrated form. Residue No 411 and partly also 161 were converted into 3,5-dinitrotyrosine. The accessibility of the individual tyrosine residues to the nitrating agent is discussed with respect to their positions in disulfide loops and hypothetic parts of the secondary structure of albumin.


2007 ◽  
Vol 98 (20) ◽  
Author(s):  
Takaaki Sato ◽  
Teruyuki Komatsu ◽  
Akito Nakagawa ◽  
Eishun Tsuchida

2013 ◽  
Vol 17 (01n02) ◽  
pp. 56-62 ◽  
Author(s):  
Kazutaka Hirakawa ◽  
Keito Azumi ◽  
Yoshinobu Nishimura ◽  
Tatsuo Arai ◽  
Yoshio Nosaka ◽  
...  

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.


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