[Spectrophotometric and fluorometric study of albumins and hemin interactions with aromatic antioxidants].
Difference spectrophotometry and fluorescence quenching of human and bovine serum albumins were used to determine their association constants (Ka) with hemin in buffered physiological saline (pH 7.4) supplemented with 2% dimethylsulfoxide or in 40% aqueous dimethylformamide (pH 7.4). Ka values depended on the medium, the extent of albumin delipidation, and on the method of determination. The formation of hemin complexes with o-phenylenediamine, tetramethylbenzidine, gallic acid, its polydisulfide, and two substituted di-tert-butyl pyrocatechols was studied by difference spectrophotometry in the same media; Ka values for the complexes were calculated and compared to each other. The formation of complexes of these aromatic ligands with albumins was studied fluorometrically; Ka values were of order of approximately 10(-5) M-1 and decreased with the ligand hydrophobicity.
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Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Minsk.
Puchkaev
A V
AV
Ivanov
A I
AI
Metelitsa
D I
DI
D000818:Animals; D000975:Antioxidants / Q000737:chemistry*; D002417:Cattle; D006427:Hemin / Q000737:chemistry*; D006801:Humans; D007700:Kinetics; D012709:Serum Albumin / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry; D013050:Spectrometry, Fluorescence
D000975:Antioxidants; D012709:Serum Albumin; D012710:Serum Albumin, Bovine; D006427:Hemin