COMPLETE PRIMARY STRUCTURE OF THE MOLT-INHIBITING HORMONE (MIH) OF THE MEXICAN CRAYFISH PROCAMBARUS-BOUVIERI (ORTMANN)

The amino acid sequence of MM was elucidated by means of digestions wi th specific proteases, manual Edman degradation, and mass spectrometry . MM consists of a 72-residue peptide chain (molecular mass 8322 Da) w ith six cysteines forming three disulfide bridges that connect residue s 7-43, 23-39, and 26-52. It has blocked N- and C-termini and lacks tr yptophan, histidine, and methionine. MM shows striking similarity to t he crustacean hyperglycemic hormone (CHH) isomorphs of Procambarus bou vieri (90% identity) and to the MIH from Homarus americanus (79% ident ity) and Penaeus vannamei (46% identity). It is also related to the MM from Carcinus maenas (28% identity) and Callinectes sapidus (28% iden tity).