Characterization of serum alkaline phosphatase separated at or near the origin in polyacrylamide gel using detergents, antibodies and neuraminidase

Abstract

We studied serum samples which showed alkaline phosphatase (ALP) activity at or near the origin of the polyacrylamide gel electrophoresis. 1) Sucrose monolaurate (final concentration, 1.7%) treatment produced a new ALP band (SM-ALP band). 2) The SM-ALP band disappeared from the original region with anti-human placental ALP antibody and appeared at the high molecular region. 3) ALP activity of SM-ALP band was completely inactivated by heat treatment (at 65°C for 10 min). 4) The molecular mass was estimated to be approximately 350 kDa by a 5-20% (linear gradient) polyacrylamide slab gel electrophoresis. We concluded that the SM-ALP band was intestinal ALP tetramer.