A combination of absorption, electron para-magnetic resonance (EPR), and resonance Raman (rR) spectroscopy has been used to study the interaction of heme-A beta and apomyoglobin (apoMb). The absorption spectrum of oxidized heme bound A beta, characterized by a split Soret band at 364 and 394 nm, shifts to 408 nm on incubation with apoMb, characteristic of Myoglobin (Mb). The v(4), v(3), and v(2), bands in the rR spectrum of heme-A beta are observed at 1376, 1495, and 1570 cm(-1), which shift to 1371, 1482, and 1563 cm(-1), respectively on incubating with apoMb, implying formation of Mb. Similarly, heme transfer from reduced heme-A beta to apoMb resulting in the formation of deoxyMb was also observed. Thus, spectroscopic data show that apoMb can sequester heme from heme-A beta complexes both in oxidized and in reduced forms. Heme uptake by apoMb from native heme-A beta(1-40) and A beta(1-16) in both oxidized and reduced forms follow a biphasic reaction kinetics likely representing heme transfer from two dominating conformers of heme-A beta in solution. The rate constants for the two steps involved in heme uptake by apoMb from heme-A beta(1-40) are 11.5 X 10(4) M-1 s(-1) and 7.5 X 10(3) M-1 s(-1) while from heme-A beta(1-16) are 6.0 X 10(4) s(-1) and 7.5 X 10(3) M-1 s(-1). The rate constants for heme uptake by apoMb from reduced heme-A beta(1-40) are 3.7 X 10(4) M-1 s(-1) and 6.8 X 10(3) M-1 s(-1) while for reduced heme-A beta(1-16) are 2.0 X 10(4) M-1 s(-1) and 6.0 X 10(3) M-1 s(-1). The heme uptake from heme-A beta by apoMb leads to a dramatic reduction of PROS generation by the reduced heme-A beta complexes.