Some properties of liver alkaline phosphatase from the goat Capra hircus.

1. Gel-filtration of an extract from the liver of the local Hausa goat Capra hircus indicated the presence of two molecular forms of alkaline phosphatase (orthophosphoric monoester phosphohydrolase, E.C. 3.1.3.1.). 2. Cellulose acetate electrophoresis showed that the lower-molecular-weight form had a similar electrophoretic mobility to alpha 2-globulin from goat serum, whereas the higher-molecular-weight form had a similar electrophoretic mobility to gamma-globulin. 3. Only the lower-molecular-weight form was detected on electrophoresis of a liver extract which contained some residual n-butanol used in the extraction procedure, whereas dialysed acetone powder obtained from the liver extract contained both molecular-weight forms. 4. The partially purified enzyme showed maximum activity at pH 9.8, and was stimulated by Mg2+. 5. The enzyme was heat-labile, and was competitively inhibited by phosphate ions but uncompetitively inhibited by L-phenylalanine. 6. These results are discussed in terms of the properties of the enzyme from other sources.