N- glutamic Acid

Fig. 8. Moffitt plots at two different values of Xo, 212 and 216 m, for the dispersions of a copolymer of 6% i.-tyrosine with n-glutamic acid (PTGA) from 700 m i down to 240 m/i.. The plots based upon 212 m/i are an extension of the visible and near ultraviolet data represented in detail in Fig. 7. Helical form in 0.1 M phosphate buffer,...

Changes in percent of and amounts of in amino acids in tea leaves during aerobic or anaerobic incubation after feeding N-glutamic acid for 6 hours... 

More specific labelling may be obtained in a biosynthetic process using enzymic methods of synthesis. The preparation of amino acids by the reductive amination of 2-keto acids is well known. Indeed, the synthesis of N-labelled amino acids by this route is among the earliest literature on the preparation of compounds labelled with stable isotopes [73], Such reductions can be carried out enzymically and L - [a- N] glutamic acid has been prepared in good yield from 2-oxoglutaric acid and N-labelled ammonium chloride in the presence of reduced nicotinamide adenine dinucleotide phosphate [74],... 

Fig. 108 are ignored, then the data obey simple first-order kinetics with a rate of the same order of magnitude as that found for simple peptides. Bryan and Nielsen also point out that urea has only a small effect on the exchange rate in poly-DL-alanine and that poly-n-glutamic acid exchanges very. slowly under conditions where it exists as a helix in solution. On the basis of these observations, as welt as recent infrared work (Elliott et al., 1958 Elliott, 1959), Bryan and Nielsen suggest tliat it is unlikely that a substantial fraction of poly-nn-alanine is in the a-helical form in aqueous solution between 0 and 22°C. they further point out that this question has to be reconsidered. 

A D-glutamic acid oxidase has been purified a himdredfold from Aaper-giUua ustus 103, 104). The enzyme deaminated n-glutamic acid and D-as-partic acid but had no activity with other DL-amino acids. The enzyme resembled that prepared from the octopus in its other properties 101). Thus, the optimum pH is 8 for both substrates and it appears, on the basis of inhibition and purification studies, that one enzyme is involved here as well. The enzyme is inhibited by 10 M concentration of KCN and p-chlo-romercuribenzoate but not by metal-binding agents. 

FIGURE 10.15 Separation of 17-component amino acid hydrolyzate. Conditions Column, Dionex AS-8 gradient. Peaks (25 nmol each, except 12.5 nmol for cystine) a, arginine b, lysine c, threonine d, alanine e, glycine f, serine g, valine h, proline i, isoleucine j, leucine k, methionine 1, histidine m, phenylalanine n, glutamic acid o, aspartic acid p, cystine and q, tyrosine. (Reprinted from Welch, L.E., LaCourse, W.R., Mead, D.A., Jr., and Johnson, D.C., Ana/. Chem., 61, 555, 1989.)... 

HOiC—CH—NH,. . CO—CH—NH, + HO2C—CHrCHrCH—NHj.. . HO2C—GHj-CH CH—NHj a-Peptide of n-glutamic acid D-Glutamic acid... 

The occurrence of n-glutamic acid in the capsular substance of capsulated strains of Bacillus anthrads and related organisms was... 

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