• Open Access

Cover Picture: Metal-Conjugated Affinity Labels: A New Concept to Create Enantioselective Artificial Metalloenzymes (ChemistryOpen 2/2013)



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The cover picture illustrates the concept of using metal-conjugated affinity labels (m-ALs) to convert proteases into well-defined and catalytically active artificial metalloenzymes. The X-ray structure of the papain-bound inhibitor E64c (orange) served as the basis to predict the orientation of the half-sandwich rhodium(III) moiety (yellow sphere) within the binding pocket of the protease. The well-defined position of the affinity label on the protein surface leads to a distinct environment of the metal center, which translates into enantiomeric ratios of up to 82:18 in the aqueous hydrogenation of ketones. For more details, see the Communication by Jörg Eppinger et al., on p. 50 ff.