Structural analysis of the matrix protein from the nuclear polyhedrosis virus of Heliothis zea.

Polyhedrin from the nuclear polyhedrosis virus of Heliothis zea was analyzed. Alkali-solubilized polyhedrin consists of a 12 S aggregate of 27,000 MW subunits. Results from chemical crosslinking experiments suggest that 12 subunits are present in the 12 S aggregate. In isoelectric focusing gels, the aggregate migrates as a single entity with an isoelectric point of 5.9. Under denaturing conditions, four charge isomers of the subunits are revealed. The presence of alkaline protease activity in the Heliothis virus is confirmed.