Molt-inhibiting hormone (MIH) is a principal endocrine hormone regulating the growth in crustaceans. In total, nine MIH peptide sequences representing members of the family Penaeidae (Penaeus monodon, Litopenaeus vannamei, Marsupenaeus japonicus), Portunidae (Portunus trituberculatus, Charybdis japonica, Charybdis feriata), Cambaridae (Procambarus bouvieri), Parastacidae (Cherax quadricarinatus) and Varunidae (Eriocheir sinensis) were selected for our study. In order to develop a structure based phylogeny, predict functionally important regions and to define stability changes upon single site mutations, the 3D structure of MIH for the crustaceans were built by using homology modeling based on the known structure of MIH from M. japonicus (1J0T). Structure based phylogeny showed a close relationship between P. bouvieri and C. japonica. ConSurf server analysis showed that the residues Cys(8), Arg(15), Cys(25), Asp(27), Cys(28), Asn(30), Arg(33), Cys(41), Cys(45), Phe(51), and Cys(54) may be functionally significant among the MIH of crustaceans. Single amino acid substitutions 'Y' and 'G' at the positions 71 and 72 of the MIH C-terminal region showed an alteration in the stability indicating that a change in this region may alter the function of MIH. In conclusion, we proposed a computational approach to analyze the structure, phylogeny and stability of MIH from crustaceans.
Keywords: CHH; Homology modeling; Hormones; In silico mutagenesis; MIH; Molt-inhibiting hormone; RMSD; Structure-based phylogeny; crustacean hyperglycemic hormone; molt-inhibiting hormone; root mean square distance.
© 2013.