ABSTRACT
In the last 10 years extensive work by a variety of groups was un dertaken to elucidate the structural and mechanistic aspects of the iso merization reaction and to understand the role and the spectroscopic properties of the metal binding sites. Mainly on the basis of X-ray crys tallographic work, a metal-mediated 1,2-hydride shift mechanism was postulated, which is now the generally accepted scheme for the mecha nism (Fig. 1). This is in contrast to the well-studied proton transfer mechanism, which involves the formation of an ene-diol or diolate in termediate, and is utilized by the metal ion-independent phosphosugar isomerases such as triose-phosphate isomerase [16,17].
