W. Garzon-rodriguez et al., Binding of Zn(II), Cu(II), and Fe(II) ions to Alzheimer's A beta peptide studied by fluorescence, BIOORG MED, 9(15), 1999, pp. 2243-2248
Binding of Zn(II), Cu(II) and Fe(II) ions to A beta 1-40, A beta 1-42 and a
single tryptophan mutant of A beta 1-40 in solution at pH 7.4 was studied
by fluorescent titration. Job plots and fitting of titration curves reveale
d formation of 1:1 and 1:2 peptide-metal complexes. For dimeric peptides A
beta 1-40 and A beta F4W the order of metal to peptide affinities is Fe < C
u > Zn, which is in agreement with the Irving-Williams series of complex st
ability. The affinity of A beta 1-42 for. Fe increases dramatically upon ag
gregation: K-D changes from ca. 100 to ca. 0.2 mu M. (C) 1999 Elsevier Scie
nce Ltd. All rights reserved.