Figure 1.

(A) Amino acid sequence alignment of goldfish leptin-AI, goldfish leptin-AII, human leptin and mouse leptin. The conserved amino acid residues are boxed in black, and similar amino acid residues are labeled in gray. The sequence identities among these four leptins are also listed; (B) Expression and purification of recombinant goldfish leptin-AI protein; (C) Expression and purification of recombinant goldfish leptin-AII protein. UI: the total supernatant of the culture without methanol induction; I: the total supernatant of the culture with methanol induction; P: isolated protein after Ni-column purification and PD-10 column desalting; M: protein marker. SDS-PAGE: sodium dodecyl sulfate polyacrylamide gel electrophoresis; WB: Western blot analysis.