DNA-containing and empty hepatitis B virus core particles bind similarly to envelope protein domains

DNA synthesis within the hepatitis B virus (HBV) nucleocapsid appears to be coupled to nucleocapsid envelopment. The nature of the envelopment signal is unknown, but is thought to involve a conformational change at the surfac e of the capsid that facilitates interaction with HBV envelope proteins. In binding assays in vitro, it was found that empty HBV core particles bound synthetic peptides corresponding to HBV envelope protein domains with the s ame affinity as did HBV DNA-containing core particles. This suggests that t he selection of replication-competent nucleocapsids for envelopment is not related to the capacity of DNA-containing core particles to bind specifical ly to HBV envelope proteins, and that there must be an alternative mechanis m.