Characterization of Solubilized Proteins from Tissue Culture-and Host-Derived Nuclear Polyhedra of Lymantria dispar and Autographa californica

Abstract

A proteolytic activity capable of degrading solubilized proteins has been detected by SDS-PAGE in alkaline carbonate-chloride dissolutions of polyhedra isolated from the larvae of Lymantria dispar and Autographa californica. This activity could not be detected in dissolutions of the respective tissue culture-derived polyhedra. However, tissue culture-derived polyhedra passaged once through their respective hosts displayed the proteolytic activity. Proteolytic degradation was prevented by either heating an aqueous suspension of polyhedra at 70° for 20 min prior to dissolution or adding a proteolytic enzyme inhibitor (phenylmethylsulfonyl fluoride) to the dissolutions.