C-terminal deletion analogs of a crustacean pigment-dispersing hormone

Peptides. 1985 Nov-Dec;6(6):1051-6. doi: 10.1016/0196-9781(85)90427-9.


This study deals with the effect of deamidation and C-terminal truncation on the potency of an octadecapeptide pigment-dispersing hormone (PDH: Asn-Ser-Gly-Met-Ile-Asn-Ser-Ile-Leu-Gly-Ile-Pro-Arg-Val-Met-Thr-Glu-Ala- NH2), first described as light-adapting distal retinal pigment hormone (DRPH) from Pandalus borealis. Bioassay of synthetic analogs for melanophore pigment dispersion in destalked fiddler crabs (Uca pugilator) showed that deamidation causes a 300-fold decrease in potency. The analogs 1-17 NH2 and 1-16 NH2 were about 3 times more potent than 1-18-OH. Further truncation led to decreases in potency, with the peptide 1-9-NH2 being the smallest C-terminal deletion analog to display activity (0.001% potency). Smaller analogs (1-8-NH2, 1-6-NH2 and 1-4-NH2) were inactive when tested in doses as high as 500 nmoles/crab. On the basis of our earlier work on N-terminal deletion analogs and the present findings the residues 6 to 9 seem to be important for PDH action.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Brachyura
  • Chromatography, High Pressure Liquid
  • Indicators and Reagents
  • Melanophores / drug effects
  • Peptides / chemical synthesis*
  • Peptides / isolation & purification
  • Peptides / pharmacology
  • Structure-Activity Relationship


  • Indicators and Reagents
  • Peptides
  • melanophore-dispersing hormone