SOLUBILIZATION AND EXTRACTION OF ALLANTOINASE AND ALLANTOICASE FROM THE GREEN-ALGA CHLAMYDOMONAS-REINHARDTII

Several physical and chemical methods for the solubilization and extra ction of allantoinase and allantoicase from the unicellular green alga Chlamydomonas reinhardtii have been tested and compared. Of all the m ethods employed (i.e. freezing-thawing, extraction at high ionic stren gth, disruption with the French press, sonication, and detergent solub ilization) sonication gave the best results for extraction of both sub stances, while sodium deoxycholate extracted allantoinase optimally bu t not allantoicase. Allantoinase and allantoicase were characterized a s two separate enzyme proteins differently associated with membranes o r located in different cellular compartments. It is also demonstrated that allantoate is enzymatically degraded in vitro by a cell-free alga l extract and that allantoicase is the enzyme responsible for this cat abolism.