PHASE PARTITIONING DETECTS DIFFERENCES BETWEEN PHOSPHOLIPASE-RELEASED FORMS OF ALKALINE-PHOSPHATASE - A GPI-LINKED PROTEIN

A number of enzymes are known to release alkaline phosphatase and other glycan phosphatidylinositol-anchored proteins from membrane surfaces. We describe a novel approach to detect and measure these activities by partitioning in aqueous phase systems. The procedures avoid the complications of micelle-formation involving hydrophobic molecules that may arise with detergent-based partition systems and can clearly distinguish between inositol-specific phospholipase C and D activities.