Purification and characterization of simian foamy virus type I structural core polypeptides.

The present study concerns the purification and partial characterization of simian foamy virus type 1 (SFV 1) structural core polypeptides. The obtention of SFV 1 cores separated from envelope components after viral disrupture was verified by electron microscopy (EM), density gradient, and polyacrylamide gel electrophoresis (PAGE). Multistep purification by column chromatography, verified by PAGE, enabled us to separate the structural core polypeptides from the 80,000 molecular weight reverse transcriptase. Two species of structural core polypeptides were identified with apparent molecular weights of 51 and 15 kd. By affinity chromatography on a double-stranded DNA-cellulose column, the main internal protein, p51, was shown to be composed of a major 30 kd protein and a minor 19 kd polypeptide, which binds to double stranded DNA. The p15 internal protein was shown to have a ribonucleotide binding nature.