Glutamate metal induction

Interaction of bivalent metal cations with poly(glutamic acid) has been extensively investigated 6-17), including the induction of a-helix formation by transition metal ions. Nevertheless, available data are not sufficient to explain the wide variety of metal-ion-induced conformational changes. 

Asymmetric induction using a transition metal complex (67), use of a carbohydrate template (68), and use of the chiral lactone 49 (69) or ester 50 (70) have all given effective syntheses of stereospecifically labeled samples of glycine. A further synthesis by Santaniello etal. (71, 72) has used glutamate decarboxylase to prepare labeled samples of y-aminobutyric acid 51 (Scheme 16). On cyclization, protection, and oxidation, these gave the labeled enamides 55, which were degraded to the labeled samples of glycine 23 (71, 72). 

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