Purification and some of the properties of alkaline phosphatase in guinea fowls (Numida meleagris galeata).

1. Alkaline phosphatase activity in the plasma of different strains of guinea fowls showed considerable variation both within and between sexes as well as within and between strains. 2. The enzymes from different strains of wild guinea fowls had different mobilities on disc polyacrylamide electrophoresis but each was characterised by a single band. 3. When the enzyme was purified 163-fold from the plasma of a domesticated grey breasted strain, both ion-exchange chromatography and gel-filtration purification steps yielded a single band of enzyme. 4. The purified enzyme had a molecular weight of 79,400 +/- 3,000 and was stable up to 60 degrees C at the optimum pH of 9.6. 5. Evidence is provided that guinea fowl alkaline phosphatase is a metalloenzyme.