Stereoselective electron-transfer reactions of the optically active ruthenium(III) complexes with hydrophobic side-chains with azurin(I) from Alcaligenes xylosoxidans GIFU 1051

In order to investigate the electron-transfer site of azurin, one of the electron-transfer proteins, some optically active Ru(III) complexes bearing hydrophobic amino acid side-chains as the molecular recognition probe have been prepared, and have been applied for the reaction with azurin-1Cu(I) from Alcaligenes xylosoxidans GIFU 1051. The estimated second-order rate constants and activation parameters, ΔH≠ and ΔS≠, have indicated enantio- and stereoselectivities. The comparison with that for azurin-2, another species isolated from the same source, has strongly suggested that the electron-transfer site of azurin is His117.