Purification of VLF-1. Baculovirus expression. Nuclear extracts (NE) were prepared at 60 h postinfection from S. frugiperda cells infected with wild-type (WT) AcNPV (lane 2) or the recombinant Ac-VLF1 (lane 3). Nuclear extracts were purified on a heparin (Hep) column, and peak fractions (lane 4) were further purified on a Mono S column (S) (lane 5). Each lane contains 2 μg of protein. Lane 1, crude extract; lane 2, protein eluted from Talon matrix with 100 mM imidazole; lane 3, peak fraction from a Mono S column. The position of VLF-1 is indicated by an arrow on the right, and the positions of relevant molecular markers are indicated on the left.