Environment of tryptophan residues in various conformational states of alpha-lactalbumin studied by time-resolved and steady-state fluorescence spectroscopy.
Decay curves for tryptophan fluorescence of bovine and human alpha-lactalbumin in different states (metal-free and Ca2+ or Mg2+-loaded states of the native and thermally denatured proteins) have been measured at different wavelengths. The curves are best fitted by a sum of three exponents assigned to emission of individual tryptophan residues. The results suggests that the red shift of the fluorescence spectrum of alpha-lactalbumin caused by release of the bound Ca2+ or thermal denaturation is due to changes in the environment of all emitting tryptophan residues.
Institute of Biological Physics, U.S.S.R. Academy of Sciences, Pushchino, Moscow.
A V
AV
Ostrovsky
L P
LP
Kalinichenko
V I
VI
Emelyanenko
A V
AV
Klimanov
E A
EA
Permyakov
D000818:Animals; D002417:Cattle; D006801:Humans; D007700:Kinetics; D007768:Lactalbumin; D011487:Protein Conformation; D013050:Spectrometry, Fluorescence / Q000379:methods; D014364:Tryptophan
D014364:Tryptophan; D007768:Lactalbumin