Restriction digests of the clone give the following sizes (kb): BamHI--5.0; EcoRI/PstI--4.0, 1.0; EcoRI/EcoRV--3.2, 1.8. The resulting protein contains two additional amino acids at the amino terminus (Gly-Ser). Expression vector for rapid purification of fusion proteins and release of proteins with fewer extraneous N-terminal amino acids. The glutathione S-transferase (GST) fusion protein can be purified by glutathione affinity chromatography, and the desired polypeptide released from the fusion product by thrombin. Constructed from pGEX-1 by inserting an oligonucleotide at the BamHI site which encodes the glycine "kinker" and thrombin recognition site to enhance cleavage of the fusion protein. |
