Fig. 2

Expression and intein-mediated cleavage of fusion proteins. a Expression of five target peptides using the peptide-intein-ELK16 construct, designated with GLP1, IGF1, SDF1, CCL5, and Leptin. b Expression of six target peptides using the Trx-peptide-intein-ELK16 construct, designated with T-Ex4, T-GLP1, T-BNP, T-SDF1, T-CCL5, and T-IGF1. Lane IL, insoluble fraction of cell lysate after washing twice with buffer B1; lanes IC and SC, insoluble and soluble fraction of cleaved fusion protein; lane PU, final product of target peptide after RP-HPLC purification; lanes 1, 2, and 3, quantification standards (Std) consisting of bovine serum albumin (BSA, 66.5 kDa) at 3, 1.5, and 0.75 µg/lane and aprotinin (6.5 kDa) at 1. 5, 0.75, and 0.3 µg/lane respectively; lanes 4, 5, 6, and 7, quantification standards (Std) consisting of bovine serum albumin (BSA, 66.5 kDa) at 6, 3, 1.5, and 0.75 µg/lane, respectively. The molecular masses of the protein standards M1 and M2 are listed by the left and right side separately