We found that the amyloid beta peptide A[1-42] is capable of interacting with membrane and forming heterogeneous ion channels in the absence of any added Cu²⁺ or biological redox agents that have been reported to mediate A[1-42] toxicity. The A[1-42]-formed cation channel was inhibited by [Cu²⁺]_cis in a voltage- and concentration-dependent manner between 0 and 250 µM. The [Cu²⁺]_cis-induced channel inhibition is fully reversible at low concentrations between 50 and 100 µM [Cu²⁺]_cis and partially reversible at 250 µM [Cu2+]_cis. The inhibitory effects of [Cu²⁺]_cis between 50 and 250 µM on the channel could not be reversed with addition of Cu²⁺-chelating agent clioquinol (CQ) at concentrations between 64 and 384 µM applied to the cis chamber. The effects of 200-250 µM [Cu²⁺]_cis on the burst and intraburst kinetic parameters were not fully reversible neither with wash nor with 128 µM [CQ]_cis. The kinetic analysis of the data indicate that Cu²⁺ induced inhibition was mediated via both desensitization and an open channel block mechanism and that Cu²⁺ binds to the histidine residues located at the mouth of the channel. It is proposed that the Cu²⁺-binding site of the A[1-42]-formed channels are modulated with Cu²⁺ in a similar way to those of channels formed with PrP[106-126] suggesting a possible common mechanism for Cu²⁺ modulation of A and PrP channel proteins linked to neurodegenerative diseases.