Extraction
Extraction of antiviral protein was performed at
4C according to the method of Takanami et al. [l 1]
with some modifications. Lyophilised root tissues ( 100
g) were homogenized with 20 vols. of buffer A (10
mM sodium phosphate buffer, pH 7.2, 0.1% 2-mercaptoethanol)
in a Waring blender for 2 x 1 min and
the extract filtered through muslin cloth. After centrifugation
of the filtrate at 5000 g for 15 min, the
supernatant was collected. The residue was reextracted
with l0 vols of buffer A, and the two supernatants
pooled. The extracted proteins were fractionated
by adding (NH4)2SO4 to 40% saturation.
After centrifugation at 5000 g for 20 min, the supernatant
obtained was adjusted to 90% saturation with