Cytoplasmic crystalline inclusions could be isolated and partially purified from infiuenza/WSN-infected chick fibroblasts by extraction of the cytoplasmic homogenate with fluorocarbon, followed by sedimentation to equilibrium in potassium tartrate gradients. Repeated analyses of the crystal-enriched fraction by PAGE showed it to be predominantly protein (mol. wt. 23,000 daltons) with a minor contamination of 2–10% by a protein of mol. wt. 60,000 daltons, which comigrated with the NP protein. The latter is believed to exist within characteristic cytoplasmic and nuclear helices, also described in this study. The molecular weight data suggest that the crystals are composed of the so-called nonstructural protein.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.