Alkaline phosphatases catalyze the hydrolysis of phosphate groups from many types of molecules, including nucleotides, proteins, and alkaloids. Three isozymes of alkaline phosphatases have been identified in humans, two of which are tissue-specific placental alkaline phosphatase (PLAP), intestinal alkaline phosphatase (IAP), and tissue non-specific alkaline phosphatase (TNAP). While the biological function of PLAP is unknown, PLAP-like enzymes have been detected in the serum of patients with primary testicular tumors and other cancers. ML-095 is an inhibitor of PLAP (IC50 = 3.7 μM) that demonstrates high selectivity against the related alkaline phosphatases, TNAP and IAP (IC50s > 100 μM).
