C-terminal deletion analogs of a crustacean pigment-dispersing hormone.
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.
D000595:Amino Acid Sequence; D000818:Animals; D003386:Brachyura; D002851:Chromatography, High Pressure Liquid; D007202:Indicators and Reagents; D008547:Melanophores / Q000187:drug effects; D010455:Peptides / Q000138:chemical synthesis* / Q000302:isolation & purification / Q000494:pharmacology; D013329:Structure-Activity Relationship
D007202:Indicators and Reagents; D010455:Peptides; C027714:melanophore-dispersing hormone