Nucleoproteins of white clover

Abstract

Ultracentrifugal examination of clover-leaf extracts has shown 2 components of high sedimentation coefficient to be present. The heavier of these has been isolated and shown to be a ribonucleoprotein containing 50-55% of ribonucleic acid. Its properties have been studied by ultracentrifuging and electrophoresis. In common with similar ribonucleoproteins from pea shoots, yeast or liver cells, this component dissociates into subunits in the presence of certain buffer solutions. The 2d component is considerably less stable, and has not yet been isolated. It is suggested that it may also be a ribonucleoprotein. The possibility of contamination of plant virus preparations with these normal constituents of leaf is discussed.