Adenosine deaminase from Saccharomyces cerevisiae: purification and characterization

Adenosine deaminase from Saccharomyces Cerevisiae was purified about 1600 fold by salt fractionation, ion exchange and affinity chromatography. Some physico-chemical properties have been determined: the molecular weight of the enzyme by gel filtration is 85,000 daltons; one -SH is readily titrated by paramercuribenzoate per 78,000 mol. weight; optimum pH is 7; Km for adenosine is 40.7 microM; 2'-deoxyadenosine is not a substrate. Deazaadenosine analogues are good inhibitors, while erythro-9-(2-hydroxy-3-nonyl) adenine binds with low affinity. These properties are compared with those of other adenosine deaminases.