Abstract
Starting from TO-fraction, a nucleic acid-free polypeptide fraction obtained by methanol-acetic acid extraction of a crude toxohormone preparation, the active substance was concentrated by means of adsorption on powdered cellulose from 0.1N acetic acid and elution with 0.1N hydrochloric acid. The hydrochloric acid eluted fraction (Peak II) obtained from TO-fraction of rhodamine sarcoma was active in 1mg doses, indicating 10-fold increase in potency. The same fraction obtained from methanol-acetic acid extract of Murphy lymphosarcoma, which was digested with pepsin prior to the adsorption on cellulose, was active in 0.5mg doses.
Crystalline picrate of an active peptide was prepared from TO-fraction of rhodamine sarcoma by the procedure of pepsin digestion and subsequent precipitation with picric acid in a weakly alkaline medium. This crystalline picrate was revealed to be active in 0.1-0.2mg doses for mice.
The amino acid composition of each fraction was determined by paper-DNP technique.
The homogeneity of the crystalline picrate was discussed and the possibility of obtaining more active peptide than that presented in this paper was suggested.
