Selection of Different Reactive Sites by Enantiomers in Electron-Transfer Reactions Involving Metalloproteins

摘要

The identification of the exact site of attack in electron-transfer reactions involving metalloproteins has been the object of many studies. In the case of plastocyanm (PcCu~(11)) two sites have been identified, the "adjacent site" near the copper center and the "remote site" located near a negative patch of the protein, some 16 A away from the copper center. Negatively charged or neutral metal complexes are thought to react exclusively at the hydrophobic adjacent site, whereas positiveh charged reagents can react at both the adjacent and or the remote site. In the latter case the neighboring Tyr83 probabix intervenes in the electron transfer pathway. In order to obtain more detailed information on the location of the attack of electron-transfer reagents, we used optically active metal complexes, our aim being the detection of chiral recognition by means of kinetic stereoselectivitv.