Isolation and primary structure of the eclosion hormone of the tobacco hornworm

Eclosion hormone was isolated from trimmed pharate adult heads of Manduca sexta by an eight step purification procedure using a Heliothfs uirescens in uiw, bioassay. The neuropeptide was active in second stadium M. sexfa. The primary structure was determined by sequence analyses of the intact peptide and fragment peptides generated by lysyl endopeptidase. endoproteinase Glu-C. and proline-specific endopeptidase. The nature of the carboxyl terminus as a free acid was elucidated by analysis of amino acids from digestion of the intact peptide with lysyl endopeptidase, which liberated leucine, but no leucine amide. The complete primary structure of M. sexta closion hormone is H-Asn-Pro-~a-Ile-Ala-Thr-Gly-Tyr-Asp-Pro-Met-Glu-Ile-Cys-IleGlu-Asn-Cys-Ala-Gln-Cys-Lys-Lys-Met-Leu-Gly-~a-~-Phe-Glu-Gly-Pro-Leu-Cys-Ala-GluSer-Cys-Ile-Lys-Phe-Lys-Gly-Lys-Leu-Ile-Pro-Glu-Cys-Glu-Asp-Phe-Ala-Ser-Ile-Ala-Pro-PheLeu-Asn-Lys-Leu-OH.