Studies on the Physiological Activities of Ricin from Castor Bean. I. Purification and Pyrogenic Activity of Ricin

• Published in: Eisei kagaku Vol. 20; no. 4; pp. 204 - 208
• Main Authors: KOJA, NORIKAZU, MOCHIDA, KENSHU
• Format: Journal Article
• Language: Japanese; English
• Published: The Pharmaceutical Society of Japan 1974
• ISSN: 0013-273X
• DOI: 10.1248/jhs1956.20.204

Ricin, which has a highly lethal toxicity and pyrogenic activity, was obtained in a homogeneous state from seeds of Ricinus communis by the method of Ishiguro, et al., with a little modification. Some physicochemical properties of the purified ricin were examined and the values obtained were as follows : Sedimentation constant, S20, 4.70×10-13 ; isoelectric point obtained by the electrofocusing fractionation, pH 7.30, estimated molecular weight, 53000-54000. Treatment of ricin with 2-mercaptoethanol dissociated it into two subunits with molecular weight of ca. 24000 and 30000. Chemical analysis suggested its sugar content to be 6.7% as hexose, and ricin seemed to be made up of 18 kinds of amino acid, there being no evidence for the presence of an abnormal amino acid (s). Pyrogenic activity of ricin was characterized by a long latent period and duration of fever for a long period of time, the amount of fever increased in proportion to the dose, and dose-activity correlation existed in the range of 0.05-0.2 μg/ml/kg.