Figure 1

Construction of chIL-7 prokaryotic expression vector. A PCR product of chIL-7 gene amplified from pcDNA-chIL-7/MH plasmid. Lane 1, negative control; lane 2, chIL-7 product; M, DL-2000 DNA markers. B Structure of pET20b-chIL-7/H vector. The chIL-7 gene fused with pelB signal peptide at 5′-terminus and His-tag at 3′-terminus was controlled by T7 promoter. C Restriction digestion identification. M, DL-2000 DNA markers; lane 1, pET20b-chIL-7/H plasmid; lane 2, pET20b-chIL-7/H plasmid was digested by XbaI and XhoI. D The chIL-7 gene sequence and the insertion sites in the expression vector. The signal peptide-deleted chIL-7 gene was inserted into pET20b(+) by NcoI and XhoI sites, fused with pelB signal peptide and His-tag. There are 4 potential N-glycosylated sites (NXT/S) in chIL-7.