Collagen‐binding recombinant fibronectin fragments containing type II domains

Abstract
Each of the two type II domains and four larger fragments, containing one or two type II domains of fibronectin, have been expressed in Escherichia coli. A special vector, containing a fragment encoding the cleavage site for Factor Xa, Ile-Glu-Gly-Arg, inserted immediately before the protein fragment of interest, was used. After treatment of the purified fusion proteins with reduced/oxidized glutathione, the correctly folded fibronectin fragments were released by proteolytic digestion with Factor Xa. The largest fragment, consisting of two type II and two type I domains, was the only fragment able to bind to immobilized gelatin.