Removal of heme from preparations of human chorionic somatomammotropin.

: The operations involved in the extraction of chorionic somatomammotropin from human placentas cause hemolysis of blood which is present in placental tissue and contamination of crude extract with large amounts of hematic pigments. Most of the pigments are removed by the purification procedure. The portion of purified hCS with high heme content was subjected to treatments with acid acetone and neutral butanone on the basis of procedures generally used for the separation of heme and protein portions in hemoproteins. Both treatments resulted in the removal of heme from hCS; the treatment using butanone was more efficient than the one using acetone. After treatment with both organic solvents, the immunological activity measured with radial immunodiffusion was entirely retained while binding activity on rat ventral prostate particles was slightly decreased.