Purification and some properties of a virus inhibitor occurring in leaves of Chenopodium amaranticolor.

Abstract

A purification procedure was devised for obtaining another inhibitor of virus infection than that reported previously occurring in Chenopodium amaranticolor. Frozen leaves were homogenized with neutral buffer and expressed through gauze. The expressed juice was centrifuged at a low speed. The supernatant was brought to 50% saturation with solid ammonium sulfate added slowly and centrifuged. The supernatant was then brought to 100% saturation with solid ammonium sulfate and centrifuged. The inhibitor was further purified from the obtained precipitate by Sephadex G100 and G50 gel filtration and DEAE-Sephadex ion exchange column chromatographies. The ultraviolet absorption spectrum of the purified inhibitor solution showed the typical curve of protein with a maximum absorption at about 280nm. The molecular weight of the inhibitor was determined by two physical methods. The protein may consist of a single polypeptide chain of an approximate molecular weight of 32, 000. The value of this inhibitor was larger than that of the inhibitor which had been obtained from the precipitate with lower concentration of ammonium sulfate13). The electrofocusing profile of the inhibitor showed the presence of two components having isoelectric points at pH 1.8 and 3.7 by using ampholine covering the pH range of 2.5-4.