Some properties of inhibitors of plant virus infection occurring in the leaves of Chenopodium album L

Inhibitors of TMV infection contained in the sap of Chenopodium album were precipitated with 50% saturated ammonium sulfate and the precipitate was dissolved in neutral phosphate buffer. After centrifugation, the supernatant was obtained, and the inhibitors were again precipitated with 50% saturated ammonium sulfate. This precipitation procedure was repeated five times. The final supernatant (Sa) showed inhibitory effect to TMV infection fairly comparable to the original sap, indicating that the inhibitors were not so much affected during the course of the precedure. Sa fraction was adjusted at pH 4.5 and centrifuged. The precipitate was dissolved in neutral phosphate buffer, centrifuged, and the supernatant (Si) was obtained. The Si fraction showed a somewhat decreased inhibitory activity than Sa fraction. The Si fraction was separated into two fractions by ECTEOLA cellulose column chromatography. The both fractions showed inhibitory activity of about the same degree. Sephadex G50 or G100 gel filtration chromatography showed that the inhibitors consisted of particles of various sizes. The leaf sap retained the inhibitory activity after treatment with RNase, pronase, or chloroform. The activity of the inhibitors was destroyed by phenol treatment. An attempt to isolate polysaccharide having inhibitory activity was not successful.