Comparative Studies on the Two Components in Human Chorionic Somatomammotropin

A small amount of the component accompanied with human chorionic somatomammotropin has been separated on Sephadex ion exchanger. When polyacrylamide disc gel electrophoresis was performed at pH 9.3, the two bands were very close each other in electrophoretic mobility. They possess lacogenic activity for the pigeon crop sac test. A comparison of their physicochemical properties was made. The major component was in excellent agreement with the minor more acidic component in amino acid analyses, n-terminal amino acid analyses and circular dichroism studies. Immunological studies indicated some common properties between them, whereas they differed significantly in the electrophoretic mobility of precipitin arc.