Binding of Zn(II), Cu(II), and Fe(II) ions to Alzheimer's A beta peptide studied by fluorescence.
Binding of Zn(II), Cu(II) and Fe(II) ions to A beta1-40, A beta1-42 and a single tryptophan mutant of Abeta 1-40 in solution at pH 7.4 was studied by fluorescent titration. Job plots and fitting of titration curves revealed formation of 1:1 and 1:2 peptide-metal complexes. For dimeric peptides A beta1-40 and A betaF4W the order of metal to peptide affinities is Fe < Cu > Zn, which is in agreement with the Irving-Williams series of complex stability. The affinity of A beta1-42 for Fe increases dramatically upon aggregation: K(D) changes from ca. 100 to ca. 0.2 microM.
Garzon-Rodriguez
W
W
Department of Molecular Biology and Biochemistry, University of California at Irvine, 92697, USA.
Yatsimirsky
A K
AK
Glabe
C G
CG
D000544:Alzheimer Disease / Q000378:metabolism; D016229:Amyloid beta-Peptides / Q000378:metabolism*; D001667:Binding, Competitive; D003300:Copper / Q000378:metabolism*; D006801:Humans; D007501:Iron / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D015032:Zinc / Q000378:metabolism*
D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; C098994:amyloid beta-protein (1-43); D003300:Copper; D007501:Iron; D015032:Zinc