Effect of 1-aminoanthracene (1-AMA) binding on the structure of three lipocalin proteins, the dimeric β lactoglobulin, the dimeric odorant binding protein and the monomeric α1-acid glycoprotein. Fluorescence spectra and lifetimes studies.
We studied effect of 1-aminoanthracene (1-AMA) binding on the structures of dimeric β lactoglobulin, dimeric odorant binding protein (OBP) and monomeric α(1)-acid glycoprotein (lipocalin family proteins) by monitoring fluorescence excitation spectra and measuring fluorescence lifetimes of the tryptophan residues of the proteins. Results show that binding of 1-AMA to β lactoglobulin and OBP modifies their conformation even at low probe concentration compared to that of the proteins. Structural modification induces a red shift of the fluorescence excitation spectra maximum of tryptophan residues accompanied with an increase of the third fluorescence lifetime and a decrease of its pre-exponential factor. These effects were not observed for α(1)-acid glycoprotein, probably as the result of carbohydrate presence. These data raise doubts concerning use of 1-AMA as a probe to study biological properties of β lactoglobulin and OBP.
Kmiecik
Daniel
D
Laboratoire de Biophysique Moléculaire. Université des Sciences et Technologies de Lille, Bâtiment C6, 59655, Villeneuve d'Ascq Cédex, France.
Albani
Jihad René
JR
D000818:Animals; D000873:Anthracenes / Q000378:metabolism*; D002241:Carbohydrates / Q000032:analysis; D002417:Cattle; D019281:Dimerization; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000378:metabolism; D006801:Humans; D007782:Lactoglobulins / Q000737:chemistry*; D054834:Lipocalins / Q000737:chemistry*; D009961:Orosomucoid / Q000737:chemistry*; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry; D018035:Receptors, Odorant / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013552:Swine; D014364:Tryptophan / Q000737:chemistry
D000873:Anthracenes; D002241:Carbohydrates; D005456:Fluorescent Dyes; D007782:Lactoglobulins; D054834:Lipocalins; D009961:Orosomucoid; D011506:Proteins; D018035:Receptors, Odorant; C045648:odorant-binding protein; D014364:Tryptophan; C049062:1-aminoanthracene