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 el ectron-transfer proteins, some optically active Ru(III) complexes bearing h ydrophobic amino acid side-chains as the molecular recognition probe have b een prepared, and have been applied for the reaction with azurin-1Cu(I) fro m Alcaligenes xylosoxidans GIFU 1051. The estimated second-order rate const ants and activation parameters, Delta H-not equal and Delta S-not equal, ha ve indicated enantio- and stereoselectivities. The comparison with that for azurin-2, another species isolated from the same source, has strongly sugg ested that the electron-transfer site of azurin is His 117. (C) 2000 Elsevi er Science S.A. All rights reserved.