L to D amino acid isomerization in a peptide hormone is a late post-translational event occurring in specialized neurosecretory cells.
Modification of the chirality of a single amino acid residue within a peptide chain appears to be novel additional mechanism leading to structural and functional diversification of eukaryotic bioactive peptides. This phenomenon has been studied at the cellular level in a neuroendocrine organ which elaborates a mixture of diastereoisomers of a 72-residue neuropeptide, crustacean hyperglycemic hormone. For the first time, amino acid isomerization has been shown to occur in the perikarya of fully specialized neurosecretory cells, as a late step of the maturation of the hyperglycemic hormone precursor and after propeptide cleavage. The specificity and efficiency of this phenomenon indicates the existence of a new enzyme family involved in the biogenesis of peptide hormones.
Soyez
D
D
Laboratoire Signaux Endocrines et Toxines d'Invertébrés, CNRS EP2028-Univ. Paris 6, France. soyez@biologie.ens.fr
Toullec
J Y
JY
Ollivaux
C
C
Géraud
G
G
D000595:Amino Acid Sequence; D000818:Animals; D060829:Arthropod Proteins; D003400:Astacoidea; D005260:Female; D007447:Invertebrate Hormones; D007536:Isomerism; D008297:Male; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000378:metabolism*; D009490:Neurosecretory Systems / Q000166:cytology; D011499:Protein Processing, Post-Translational
D060829:Arthropod Proteins; D007447:Invertebrate Hormones; D009419:Nerve Tissue Proteins; C015947:hyperglycemic hormone, crustacean