title: Biosynthesis and processing of placental alkaline phosphatase.
abstract: Polypeptides of 61,500 and 64,500 apparent molecular weights were the precursor and fully processed forms of placental alkaline phosphatase monomer synthesized by choriocarcinoma cells in vivo. [3H] Mannose was incorporated into both polypeptides whereas [3H] glucosamine was incorporated mainly into the 64,500-dalton polypeptide, suggesting processing by the addition of glucosamine moieties. In the absence of microsomal membranes, choriocarcinoma mRNA directed the cell-free synthesis of the preprotein form of alkaline phosphatase monomer of apparent Mr = 60,000. The unglycosylated monomer had an apparent Mr = 58,000. In the presence of microsomal membranes, the 60,000-dalton polypeptide was processed to a polypeptide of apparent Mr = 61,500, comigrating with the precursor form of alkaline phosphatase monomer.
mesh_terms: D000469:Alkaline Phosphatase / Q000096:biosynthesis*; D002460:Cell Line; D002822:Choriocarcinoma / Q000201:enzymology; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy; D014594:Uterine Neoplasms / Q000201:enzymology
chemical_list: D000469:Alkaline Phosphatase