Grain glutamic acid

Strychnine is an alkaloid grain that is absorbed when eaten by the animal. It attacks the CNS by antagonizing the action of glycine, an amino acid responsible for transmitting inhibitory nerve impulses that control muscle contraction. In addition, there is evidence of an increase in brain levels of glutamic acid, an amino acid that acts as a transmitter for excitatory nerve impulses that excite muscle contraction. As a result, the skeletal muscles become hyperexcitable and contract simultaneously without the normal restraints this is called a convulsion or seizure. Convulsions prevent respiration, a process that depends on a controlled rhythm of contraction and relaxation, causing the animal to suffocate. 

Amino acid production by fermentation started around 1960 in Japan. Initially glutamic acid was the main product. It was sold as sodium salt, monosodium glutamate (MSG), a flavor enhancer on oriental cuisine. Other amino acids soon followed. They are used in food and feed to increase the efficiency of low protein substrates. Microbiologically produced enzymes were introduced around 1970. They are used in grain processing, sugar production, fruit juice clarification, and as detergent additives (Table 9.1). 

Fig. 2 Glutamic acid decarboxylase (GAD) 67 mRNA-labeling in cerebellar Purkinje cells in the Crus 11 region of the lateral cerebellar hemisphere from an individual with autism. Note the accumulation of silver grains within the soma and apical dendrite (arrow) labeled via in situ hybridization. Scale bar =100 p.m...

Glutelins a group of simple proteins from grain. Hiey are generally insoluble in water, salt solutions and dilute ethanol, but at extreme pH values they do become soluble. Ihey contain up to 45% glutamic acid. The best known are glutenin in wheat, orycenin in rice and hordenin in barley. 

Others B-l,3-glucans derived from a variety of natural sources (such as yeasts, grain, mushroom or seaweed), poly-gamma-glutamate (amino acid polymer)... 

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