Production and Purification of GST–I-2 Fusion Proteins.
I-2F, I-2N, and I-2NK207R were produced as GST fusion proteins in E. coli and purified as described in Methods.
(A) Total protein of isopropylthio-β-galactoside–induced E. coli lysates containing I-2F (lanes 1, 5, and 9), vector-only control (lanes 2, 6 and 10), I-2N (lanes 3, 7, and 11), and I-2NK207R (lanes 4, 8, and 12) on SDS–polyacrylamide gels stained with Coomassie blue (left panel) or visualized by immunoblotting with either anti-GST antibodies (middle panel) or anti-I-2 antiserum (right panel).
(B) Purified and refolded fractions of I-2N (lanes 1, 3, and 5) and I-2NK207R (lanes 2, 4, and 6) on SDS–polyacrylamide gels stained with Coomassie blue (left panel) or visualized by immunoblotting with either anti-GST antibodies (middle panel) or anti-I-2 antiserum (right panel).