Department of Pharmacology and Physiology, University of Rochester Medical Center, 601 Elmwood Ave., Box 711, NY 14642, USA.
Vitronectin (VN) is one of the primary adhesive proteins in serum and serves to promote the attachment and spreading of a wide variety of cell types to tissue culture plastic. In this study, the pGEX2t expression vector was used to express full-length human VN as a GST-tagged fusion protein in Escherichia coli. GST/VN production was induced with IPTG and the protein was found to localize to inclusion bodies. The inclusion bodies were isolated from cell lysates, washed once with 2 M urea and Triton X-100, and then solubilized with 8 M urea in the presence of a reducing compound. Solubilized GST/VN was purified by heparin affinity chromatography and refolded by dialysis against phosphate buffered saline. Approximately 40 mg of GST/VN was recovered from 1L of bacterial culture. Purified GST/VN migrated at the predicted molecular mass on SDS-PAGE and was recognized by both anti-GST and anti-VN antibodies. GST/VN bound to heparin and promoted cell adhesion, spreading, and growth to a similar extent as that observed with plasma-derived VN. As such, the production of recombinant VN in bacteria represents a rapid and convenient method to produce large quantities of VN for cellular studies.