Glutamate, redox couple

As a redox couple, proline and pyrroline-5-carboxylate provide a mechanism for the intercompartmental and intercellular transfer of redox potential. The transfer of redox potential alters the ratio of NADP /NADPH thereby activating certain metabolic pathways. Although the reduction of pyrroline-5-carboxylate is the central mechanism in the transfer of redox potential, the metabolic interconversions of proline, ornithine, and glutamate with pyrroline-5-carboxylate as the obligate intermediate also may play a role. The endpoint of this regulation appears to be the formation of purine ribonucleotides by both salvage and de novo mechanisms. Proline and pyrroline-5-carboxylate appear to be metabolic signals which can be fine-tuned by humoral factors to coordinate the metabolism of amino acids and ribonucleotides. When the transfer is from cell to cell, proline and pyrroline-5-carboxyl-ate can function as intercellular communicators. 

Glucose oxidase, as protein-based redox probe, 1, 909 Glutamate analogs, lead triacetate arylation, 9, 391 Glutarates, via tin hydride-promoted radical coupling,... 

The strong signals in the amide I and II range (aroxmd 1,660 and 11,550 cm ) indicate the response of the protein scaffold to the redox transitions. The small bands at 1,734 cm / 1,746 cm have been assigned to a glutamic acid side chain (Glu 278) and represents the proton coupling to electron transfer. 

We describe in this section an enzyme-free electrode responsive to urea. A sensitizer used was again a synthetic polypeptide, poly(a-L-glutamate) (PLG), which undergoes conformational changes depending on the concentration of urea. PLG was easily immobilized on a Pt wire with the aid of the multiphase polymer material, poly(styrene-co-acrylonitrile)-PLG block copolymer, as described above. Electrochemical response towards urea was obtained based on the permeability change of the redox-active couple ions (the "ion-channel" mechanism). 

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