Glutamic acid formation

Friedberg and Hayden (15) reported that glutamic acid was formed when poly-L-proline was irradiated in dilute aqueous solution in the absence of 02. We also found glutamic acid formation (G = 0.14) under similar conditions and confirmed the identity of the glutamic acid by two-dimensional thin-layer chromatography. A possible intermediate in this reaction... 

Glutamic acid formation from glucose by bacteria. I. Enzymes of the Embden-Meyerhof-Parnas pathway, the Krebs cycle, and the glyoxylate bypass in cell extracts of Brevibac-terium flavum No. 2247. J. Biochem.,... 

A.M. Cromwick, G.A. Birrer, R.A. Gross, Effects of pH and aeration on gamma-poly(glutamic acid) formation by Bacillus licheni-formis in controlled batch fermentor cultures, Biotechnol. Bioeng. 50 (1996) 222-227. 

Bitter GA, Cromwick. AM, Gross RA. Camma-Poly(glutamic acid) formation by Bocillus iichenifbrmii 9945a Physiological and biochemical studies. Ini J Biol 1994 16 265-275. Shoji S, Sakai H. Poly-L-lysine produced by Streptomycetes. 111. Chemical studies. Agric Biol Chem 1981 45 2503-2508. 

Fig. 24.23. Pathway for glutamic acid formation from glucose.

Ammonia reacts with the ketone carbonyl group to give an mine (C=NH) which is then reduced to the amine function of the a ammo acid Both mine formation and reduc tion are enzyme catalyzed The reduced form of nicotinamide adenine diphosphonu cleotide (NADPH) is a coenzyme and acts as a reducing agent The step m which the mine is reduced is the one m which the chirality center is introduced and gives only L glutamic acid... 

L-Glutamic acid does not racemize in neutral solution, even at 100°C. Deviation of pH from neutral to greater than 8.5 results in thermal racemization with loss of taste characteristics. Racemization in neutral solution occurs at 190 °C after formation of the lactam, 5-oxo-L-proline, pyroglutamic acid [98-79-3]. 

The Dmab group was developed for glutamic acid protection during Fmoc/r-Bu based peptide synthesis. The group shows excellent acid stability and stability toward 20% piperidine in DMF. It is formed from the alcohol using the DCC protocol for ester formation and is cleaved with 2% hydrazine in DMF at rt. ... 

This reaction requires the formation of an hydroxide ion, as in the enzyme reaction. A proper reference reaction for the first step in the enzyme would then be simply the proton transfer from a water molecule to a glutamic acid in solution ... 

Selectivity studies with DTU indicated marked discrimination in the clathrate formation 23,45). As in other types of clathrates, the steric factor is important in differentiation between compounds of similar functionality but different shape. For example, DTU forms crystalline complexes with some alcohols (methanol, ethanol, propanol, 1-butanol) but not with others (2-butanol). It complexes the ethyl esters of N-acetyl derivatives of glycine, alanine, methionine and aspartic acid, but not of proline, serine, phenylalanine and glutamic acid. 

Surface faceting may be particularly significant in chiral heterogeneous catalysis, particularly in the N i/P-ketoester system. The adsorption of tartaric add and glutamic acid onto Ni is known to be corrosive and it is also established that modifiers are leached into solution during both the modification and the catalytic reaction [28]. The preferential formation of chiral step-kink arrangements by corrosive adsorption could lead to catalytically active and enantioselective sites at step-kinks with no requirement for the chiral modifier to be present on the surface. 

S. W. Fox (from 1984, director of the Institute for Molecular and Cellular Evolution of the University of Miami) made the highly controversial suggestion that the amino acid sequences in the proteinoids are not random. Nakashima prepared a thermal polymer from glutamic acid, glycine and tyrosine the analysis showed that two tyrosine-containing tripeptides had been formed pyr-Glu-Gly-Tyr and pyr-Glu-Tyr-Gly (Nakashima et al 1977). The result was confirmed (Hartmann, 1981). A closer examination of the reaction mechanism showed that the formation of these two tripeptides under the reaction conditions used depends on three parameters ... 

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