A new type of methylamine oxidase: the sole oxidase produced during growth of Sporobolomyces albo-rubescens on primary alkylamines.

Under conditions known to separate methylamine oxidase from benzylamine oxidase in other yeast strains, only a single oxidase could be detected in Sporobolomyces albo-rubescens. This occurred irrespective of whether methylamine or n-butylamine was the nitrogen source for growth. The oxidase did not attack benzylamine. It was concluded that this organism can only produce a methylamine oxidase. The enzyme was purified to 90% homogeneity and found to have properties significantly different from the methylamine oxidases previously characterised. It lost only 40% of its activity in 30 min at 45 degrees C, whereas methylamine oxidases previously described had half-lives of from 2 to 9 min at 45 degrees C. It showed also a lower activity with short chain 1-aminoalkanes and a higher activity with longer chain 1-aminoalkanes than other methylamine oxidases, and had a significantly smaller subunit molecular weight (57,000 compared with 80,000).