Purified preparations of tobacco necrosis virus (<i>Nicotiana</i>virus II)

Abstract

Two nucleoproteins with similar chemical composition have been isolated from the leaves of tobacco plants infected with tobacco necrosis virus. One of these is crystalline and has a sedimentation constant of 130 × 10 −13 ; the other is amorphous and its principal component has a sedimentation constant of 58 × lO −13 . Each preparation will infect plants at a dilution of 1 in 108 and will precipitate specifically with antiserum at a dilution of 1 in 3·2 × 10 5 . The nature of the difference between preparations in the two states is obscure and it has not proved possible to convert the one into the other.