Properties of adenosine deaminase from Candida albicans

Adenosine deaminase (ADA; adenosine aminohydrolase, E.C. 3.5.4.4), a purine catabolic enzyme, was studied in Candida albicans, an opportunistic yeast that causes diseases ranging from superficial infections to the deep system ic disease, candidiasis, in immunosuppressed humans. The fungus was grown a s a yeast form in LEE's synthetic medium, pH 4.5, at room temperature for v arious growth periods. Adenosine deaminase (ADA) activity was determined fr om the cell free extract by measuring the change in absorbance 265 nm resul ting from the deamination of adenosine. In yeast form, maximum growth and A DA activity were found at 72 and 24 hours, respectively, whereas in the myc elial form both the growth and ADA activity were maximum after 48 hours. Am ong the three media tested, tryptic soy broth supported maximum growth and enzyme production, compared to LEE synthetic medium or SABOURAUD dextrose b roth. The enzyme was active over the pH range 4-8 and the optimum temperatu re for ADA activity was found to be 37 degrees C.