Studies of High-molecular Placental Components in Connection with Pregnancy Toxemia

Seventh Paper: On Proteins

Abstract

1. A protein insoluble at pH 5.0 (Protein I), a protein insoluble at pH 5.8 (Protein II), a protein insoluble at pH 6.0 (Protein III), a protein precipitable at 2/5 saturation with ammonium sulfate of its solution (Protein IV) and a protein precipitable at 1/2 saturation with ammonium sulfate of its solution (Protein V) were separated in electrophoretically _??_ homogeneous state.
2. Proteins I-II were found to contain aspartic and glutamic acids, serine glycine, threonine, alanine, tyrosine, leucine and/or isoleucine, valine and/or methionine, proline, lysine; histidine and arginine, and the Molisch-positive proteins III-V to contain phenylalanine and hexosamine in addition.
3. Quantitative composition of the proteins was determined. It is to be remarked that all of them are extraordinarily rich in proline.
4. The proteins were also examined regarding solubility, precipi-tability, ultraviolet absorption and relative viscosity.
5. The experiments of Tanaka and others revealed that, in pregnant rabbits, Proteins I-III cause liver lesion and Protein IV kidney lesion, Protein I, III and IV increase of blood pressure, Protein I decrease of urinary secretion and Proteins III-V rise of chloride ion concentration in subcutaneous tissue fluid, suggesting close connection of the proteins with the occurrence of pregnancy toxemia.
6. The proteins generally do not give the positive precipitin reaction with sera of pregnant women including pregnancy-toxemia patients.
7. Protein I and III showed tendency of giving more intensive skin reaction in pregnancy toxemia- and uterus cancer-patients, Protein II in puerperal women and uterus cancer patients and Protein IV in normal-pregnant women and pregnancy toxemia- and uterus cancer-patients than in the non-pregnant women.