FIG 3.

Mass spectrometry of purified virions of BtAdV 250-A. Purified virus was analyzed by SDS-PAGE, and individual protein bands were excised and subjected to nano-HPLC-MS/MS. Peptide sequencing identified the three major capsid proteins (hexon, fiber, and penton), the four minor capsid/cement proteins (IIIa, VI, VIII, and IX), and two of the six core proteins (V and VII). Note that the lower band in the central group of triplet bands was a mixture of both fiber and penton proteins (estimated molecular masses of 56.1 and 54.5 kDa, respectively). Peptides corresponding to proteins VII, VIII, and IX were detected in a band migrating at approximately ≤10-kDa (not visible after separation of the V-IIIa-fiber-penton cluster).