Two-dimensional analysis of African swine fever virus proteins and proteins induced in infected cells.

Two-dimensional (2D) analysis of African swine fever (ASF) virus purified by Percoll gradient centrifugation resolves 54 structural proteins, 30 in conventional IEF gels and 24 in NEPHGE gels, while only 26 structural proteins are separated by SDS-PAGE. The two main bands separated by SDS-PAGE, with mol wt 150K and 72K, correspond to single spots in 2D gels. Other bands, including major bands of 38K, 35K, 24K, 17K, and 15.5K mol wt, correspond to multiple proteins of the same molecular weight but different pI. One hundred six virus-specific proteins were resolved by 2D analysis, 59 in conventional IEF gels and 47 in NEPHGE gels. Thirty-five of the virus-specific proteins are early proteins, synthesized before DNA replication, and the remaining 71 proteins are late proteins. Early proteins belong to two groups: 11 transient early proteins are synthesized only early in infection and the other 24 are persistent early proteins, synthesized at both early and late phases. Treatment with cytosine arabinoside prevents the synthesis of late proteins and blocks the shut-off of the synthesis of transient early proteins. Eleven structural proteins are major early proteins and 28 are late proteins. The remaining 15 structural proteins migrate in 2D gels like cellular proteins. Three of these cellular proteins, with mol wt 58K, 56K, and 45K were identified by immunoblotting as alpha-tubulin, beta-tubulin, and actin, respectively.