Effects of glutamic acid

The subject of the effect of glutamic acid on "intelligence," as well as many related problems, needs to be investigated fully, bearing in mind the considerations we have presented here. 

W2. Walshe, ], M, The effect of glutamic acid on the coma of hepatic failure. Lancet i, 1075 (1953). 

Zimmerman, F. T., Burgemeister, B. B., Putnam, T. J. (1948). The ceiling effect of glutamic acid upon intelligence in children and in adolescents. The American Journal of Psychology, 104, 593—599. 

On dialysis, the activity of choline acetylase decreases rapidly. After two hours of dialysis the enzyme loses about 80 to 85 per cent of its activity. Clinical observations suggest that glutamic acid has a favorable effect on epileptic patients suffering from petit mal attacks, whereas patients with grand mat do not appear to be affected (Price, Waelsch, Putnam, 120). On the hypothesis that the slow waves which appear in the electroencephalogram during attacks of petit mal may in some way be connected with a lower rate of formation of ACh, the effect of glutamic acid has been tested on the synthesis of ACh in dialyzed extracts of rat brain. 

The a-carbon of glutamic acid is chiral. A convenient and effective means to determine the chemical purity of MSG is measurement of its specific rotation. The specific optical rotation of a solution of 10 g MSG in 100 mL of 2 A/HQ is +25.16. Besides L-glutamic acid [56-86-0] D-glutamic acid [6893-26-1] and the racemic mixture, DL-glutamic acid [617-65-2] are known. Unique taste modifying characteristics are possessed only by the L-form. 

The glutarimide best known to the lay public, thalidomide (40), owes its reputation not to efficacy, but to the wholly unanticipated and tragic teratogenic effects elicited by this compound. It might be noted that the very efficacy and lack of the usual barbiturate side effects shown by this drug led to its prescription as a hypnotic for expectant mothers. Condensation of the phthalimide of glutamic acid (39) with ammonia at elevated... 

Ward and Mason157) explain these effects by direct hydrogen bonds between the hydroxy group of hydroxyproline in position 3 and the carboxylic side chain of glutamic acid in the adjacent chains. From the sequence we know that in the case of parallel and... 

Glutamic acid is a component of many proteins, such as those in dairy products, meat, legumes, and mushrooms. However, only the free form of glutamic acid or glutamates has an effect on the glutamate receptors. When bound to other amino acids in a protein, it does not stimulate glutamate receptors. 

Sidechain conservatism may be split up into at least two kinds 1) substitutions which conserve sidechain bonding forces - providing similar electrostatic, hydrophilic, or hydrogen bonding interactions, and 2) substitutions conserving secondary structure propensity. For instance, substitution of glutamic acid with aspartic acid conserves charge, but this could have a considerable effect upon the secondary structure propensity of the peptide. 

The precise mechanism of dimethylhydrazine toxicity is uncertain. In addition to the contact irritant effects, the acute effects of dimethylhydrazine exposure may involve the central nervous system as exemplified by tremors and convulsions (Shaffer and Wands 1973) and behavioral changes at sublethal doses (Streman et al. 1969). Back and Thomas (1963) noted that the deaths probably involve respiratory arrest and cardiovascular collapse. The central nervous system as a target is consistent with the delayed latency in response reported for dimethylhydrazine (Back and Thomas 1963). There is some evidence that 1,1-dimethylhydrazine may act as an inhibitor of glutamic acid decarboxylase, thereby adversely affecting the aminobutyric acid shunt, and could explain the latency of central-nervous-system effects (Back and Thomas 1963). Furthermore, vitamin B6 analogues that act as coenzymes in the aminobutyric acid shunt have been shown to be effective antagonists to 1,1-dimethylhydrazine toxicity (reviewed in Back and Thomas 1963). 

Increases occur in the activity and amount of glutamic acid decarboxylase. Glutamate levels are not affected by bilobalide, nor are the number or dissociation constants of the GABAA receptor. Such effects were suggested to mediate the antiseizure effects of bilobalide. 

Toth E, Sershen H, et al (1992) Effect of nicotine on extraceUular levels of neurotransmitters assessed by microdialysis in various brain regions role of glutamic acid. Neurochem Res 17(3) 265-271... 

Figure 2. The effect of pH on the adsorption of glutamic acid, lysine and proline on rutile.

In addition to epilepsy, neuronal death due to the toxic effects of glutamate has also been implicated in cerebral ischaemia associated with multi-infarct dementia and possibly Alzheimer s disease. With the plethora of selective excitatory amino acid receptor antagonists currently undergoing development, some of which are already in clinical trials, one may expect definite advances in the drug treatment of neurodegenerative disorders in the near future. 

Lipscomb has commented that glutamic acid-245 might act either as a general base or a nucleophile. The available mechanistic information has been reviewed by Kaiser and Kaiser (1972), who postulated that the carboxylate anion of glutamic acid-245 acts as a nucleophile forming an anhydride intermediate [equation (29)]. The divergent D2O solvent isotope effects, =... 

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