Abstract
In measles virus-infected BGM (African green monkey kidney) cells, a unique polypeptide (84K) was identified. This polypeptide was not found in other cell lines examined and could be immunoprecipitated with anti-NP monoclonal antibody. Peptide mapping studies confirmed that it contained all the peptides of the 60K NP plus several additional ones. Pulse-chase experiments failed to establish it as a precursor of the 60K polypeptide. The possible origin of this protein is discussed.