title: The physical characteristics and enzymatic modification of fetal intestinal alkaline phosphatase in amniotic fluid.
abstract: The predominant form of alkaline phosphatase in amniotic fluid at 16 to 18 weeks gestation has the inhibition characteristics of the isoenzymes from adult and fetal small intestine. These characteristics are shared by an alkaline phosphatase of presumed intestinal origin occasionally found in the sera of premature neonates. However, in contrast to the rapid anodal migration of the latter enzyme, amniotic fluid phosphatase is of low electrophoretic mobility in polyacrylamide gel, and it has a high molecular weight. Digestion of amniotic fluid with bromelain produces a rapidly-migrating active enzyme form, with a molecular weight of about 135,000, compared with 145,000 for the fetal intestinal phosphatase in serum. The bromelain-treated amniotic fluid phosphatase is similar in size to a Kasahara isoenzyme in the serum of a cancer patient, which is itself thought to result from re-expression of a fetal intestinal phosphatase gene.
mesh_terms: D000328:Adult; D000469:Alkaline Phosphatase / Q000032:analysis*; D000653:Amniotic Fluid / Q000201:enzymology*; D001963:Bromelains; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007422:Intestines / Q000196:embryology* / Q000201:enzymology; D007527:Isoenzymes / Q000032:analysis*; D008175:Lung Neoplasms / Q000201:enzymology; D008970:Molecular Weight; D011247:Pregnancy
chemical_list: D007527:Isoenzymes; D001963:Bromelains; D000469:Alkaline Phosphatase