Protein organization in Newcastle disease virus as revealed by perturbant treatment.

Treatment of Newcastle disease virus with lithium diiodosalicylate differentially elutes the internally disposed proteins, M and NP, showing that these proteins are extrinsic, i.e., not associated with the lipid hydrophobic core. This selective elution requires disruption of the viral envelope, a process that is maximal at low temperature and influenced by the lipid composition of the virus envelope.