254] Ethanolamine deaminase (Clostridium sp.)

Abstract

This chapter discusses the methods of preparation of Ethanolamine Deaminase ( Clostridium sp.). A coupled reaction in which the acetaldehyde produced in the deaminase reaction is reduced to ethanol in the presence of added DPNH and excess alcohol dehydrogenase forms the basis of the assay. The reaction is always begun by the addition of either ethanolamine deaminase or the cobamide coenzyme to the incubation mixture because it was found that preincubation of the deaminase and coenzyme in the assay mixture in the absence of substrate resulted in diminished activity within a few seconds and over 90% inactivation within 5 minutes. The amount of enzyme required to produce a decrease in optical density of 6.20 in 1 minute is defined as 1 unit of ethanolamine deaminase activity. This decrease is equivalent to the disappearance of 1 micromole of substrate per minute. Specific activity is expressed as units per milligram of protein.