title: Biochemical and functional study of antithrombin III in newborn infants.
abstract: Antithrombin III (AT-III) was isolated by heparin affinity chromatography from adult venous and newborn term and preterm umbilical cord blood. The purified proteins were compared by SDS-PAGE, rocket immuno-electrophoresis, protein concentration by microbiuret relative to optical density at 280 nm, heparin cofactor specific activity, progressive neutralization of thrombin and factor Xa at 37 degree C and pH related antithrombin kinetics. The structural evaluations revealed a fetal AT-III of molecular weight, charge and electrophoretic migration indistinguishable from adult AT-III. The functional studies showed that, on an equimolar basis, the rates of thrombin and Xa interactions with fetal AT-III were as rapid as those with adult AT-III. The catalytic rates of various concentrations of heparin were also equal. The newborn infant, therefore, displays a quantitative but not quantitative deficiency of AT-III.
mesh_terms: D000328:Adult; D000990:Antithrombin III / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology*; D001780:Blood Coagulation Tests; D055598:Chemical Phenomena; D002621:Chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D005170:Factor X / Q000378:metabolism; D015951:Factor Xa; D005312:Fetal Blood / Q000032:analysis; D006801:Humans; D007123:Immunoelectrophoresis, Two-Dimensional; D007231:Infant, Newborn; D013917:Thrombin / Q000378:metabolism; D013927:Thrombosis / Q000097:blood
chemical_list: D000990:Antithrombin III; D005170:Factor X; D013917:Thrombin; D015951:Factor Xa