Relationship of crystallization to the nature of polyhedron protein,with reference to a nuclear-polyhedrosis virus of the silkworm, Bombyx mori

When the silkworm nuclear polyhedrosis inclusion bodies were exposed to a drop of weak alkaline solution, the protein part of the bodies dissolved, and subsequently recrystallized out with the gradual evaporation of water from the preparation under ordinary room condition. The crystals assumed a variety of crystalline forms. These crystalline forms could be demonstrated by a simulation of folding paper strips along the edge or diagonal lines of rhombi which are to be formed on the strips serially by passing parallel lines with an inclination of 60° against the strip edge. Polyhedron protein was very homogeneous and simple in nature, the sedimentation constant being around 6.26 Svedberg units (S). These protein particles were easily associated to form large complexes which gave 13.6, 19.7, 29.7, and 38.0 S in neutral solutions. Associated polyhedron protein complexes were separable into various sizes by ultracentrifuge and disc electrophoresis.