Multiple forms of bovine kidney alkaline phosphatase

Partial purification of bovine kidney alkaline phosphatase produced two fractions (F 1, F 2). Double immunodiffusion experiments using antiserum against the pooled kidney fractions showed a complete fusion of the precipitin line of bovine kidney F 2 with those of bovine kidney F 1, liver, bone, and placental alkaline phosphatases. No reaction was observed between the antiserum and alkaline phosphatase from either bovine intestine or human kidney. Crossed immunoelectrophoresis of fraction F2 produced two peaks that crossed each other and stained for enzyme activity. This finding is discussed in light of recent reports of multiple antigenic forms of alkaline phosphatase from human and rabbit kidney.