Affinity elution from a phosphonic acid-Sepharose derivative in the purification of human liver alkaline phosphatase.

The compound p-aminobenzylphosphonic acid has been coupled via an azo linkage to tyraminyl-Sepharose 4B. This derivative at pH 6.0 bound most of the protein and all of the alkaline phosphatase in a crude preparation from human liver. The phosphatase was selectively eluted with the substrate 2-naphthylphosphate and a purification of 400-fold obtained. This step, when incorporated into a procedure for the purification of human liver alkaline phosphatase, yielded essentially pure enzyme.