Transamination Is the Most Widespread Form of Nitrogen Transfer

Transamination Is the Most Widespread Form of Nitrogen Transfer 

Transamination does not result in net deamination because one amino acid is replaced by another amino acid. The main function of transamination in catabolism is to funnel the amino nitrogen into one or a few amino acids. For glutamate 

The overall process of transamination of a-ketoglutarate and regeneration of the a-ketoglutarate is shown in figure 22.4. 

Catalysis of glutamate dehydrogenase starts with a hydride transfer from the a carbon of the amino acid to NAD+ (fig. 22.5). The resulting a-iminoglutarate hydrolyzes to a-ketoglutarate and ammonia. 

Some other amino acids also undergo deamination directly by oxidative reactions. Whether transamination or direct deamination is more important as an initial step in 

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