Correct Disulfide Pairing Is Required for the Biological Activity of Crustacean Androgenic Gland Hormone (AGH): Synthetic Studies of AGH

Androgenic gland hormone (AGH) Of file woodlouse, Armadillidium vulgare, is heterodimeric glycopeptide. In this study we synthesized AGH with it homogeneous N-linked glycan using the expressed protein ligation method. Unexpectedly, disulfide bridge arrangement of it semisynthetic peptide differed from that of a recombinant peptide prepared in it baculovirus expression system, and the semisynthetic peptide showed no biological activity in vivo. To confirm that the loss of biological activity resulted from disulfide bond isomerization, AGH with it GlcNAc moiety was chemically synthesized by file selective disulfide formation. This synthetic AGH showed biological activity in vivo. These results indicate that the native conformation of AGH is not the most thermodynamically stable form, and correct disulfide linkages are important for conferring AGH activity.