Abstract
The “pregnancy zone” protein is a serum protein found in pregnancy and after administration of oral contraceptives. It has hitherto not been isolated and therefore practically nothing is known about its structure and function. Purification of this protein was achieved in three steps: 1) Gel filtration on Sephadex G-200; 2) Chromatography on DEAE-Sephadex; 3) Preparative polyacrylamide electrophoresis. After the third step a protein was obtained which was found to be pure judged by the behaviour in polyacrylamide electrophoresis and ultra-centrifugation. The molecular weight was estimated to be 326000, the sedimentation coefficient 12 S and the isoelectric point 4.7.