Serine deamination, anaerobic

This activity was measured anaerobically by Gale and Stephenson as release of ammonia by bacterial cells. The system was not stable, but was protected by low concentrations of phosphate and reducing agents. At 0 C. inactivation occurred that was reversed by a boiled bacterial extract plus phosphate and a reducing agent. The reaction was better defined by Chargaff and Sprinson, who also studied the reaction in liver. Several bacterial species were found to deaminate both n- and L-serine and threonine. Phosphate-, methyl-, and ethyl-substituted hydroxyl groups prevented the reaction. 

More important evidence, however, is the widespread distribution and high activity of dehydrases that deaminate serine in nature. The anaerobic deamination of DL-serine by cell-free extracts of many animal species proceeds extensively with the formation of pyruvic acid upon addition of Mg++. os Similar serine dehydrases occur in many bacterial species (E. colt, P. pyocyanea, P. Ox-19, and Cl. welchit). - ... 

The anaerobic deamination of L-threonine with the formation of a-ketobutyric acid is induced by the same bacterial preparations that deaminate L-serine, most probably by the same enzyme. "... 

Another e of deamination is reductive deamination as carried out anaerobically by the Clostridia. Glydne gives acetic add, alanine and serine give propionic add, etc. Although evidently hydrogen plays some part in the reaction, only amino acids are necessary. For example, two moles of glydne are reductively deaminated in the presence of Cl. sporo-genes whilst at the same time a mole of alanine is oxidized to acetic add. 

More important evidence, however, is the widespread distribution and considerable activity of serine deaminase in different organisms. The anaerobic deamination of DL-serine by cell-free liver extracts has been ob-... 

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