Purification and Some Properties of the Soluble and Membrane-Bound Adenosine Deaminases of Micrococcus sodonensis ATCC 11880 and their Distribution within the Family Micrococcaceae

Abstract

In Micrococcus sodonensis and some other Micrococcus species, adenosine deaminase is present both as a membrane-bound and a soluble enzyme. The membrane-bound adenosine deaminase can be extracted with n-butanol, and may account for up to 5% of the total cellular adenosine deaminase activity. In a number of comparative tests, no differences between the two enzyme forms could be found, thus they are believed to be similar molecular species. The purified membrane-bound or soluble enzyme had a molecular weight, obtained by gel-filtration, of 130 000 and was inactive toward adenine and adenine mononucleotides. It appears, therefore, to be more closely related to the calf-intestine enzyme than the Aspergillus oryzae form in respect to size and substrate specificity. Attempts to correlate membrane-bound adenosine deaminase activity with adenosine transport in isolated membrane vesicles of M. sodonensis indicated no obvious relationship between the two activities.