Melanin concentrating hormone (MCH): synthesis and bioactivity studies of MCH fragment analogues.
Nineteen analogues of melanin concentrating hormone (MCH) were synthesized and tested for their skin-lightening activities in the in vitro eel skin (Synbranchus marmoratus) bioassay. All the analogues synthesized were fragments of the native sequence: Asp-Thr-Met-Arg-Cys-Met-Val-Gly-Arg-Val-Tyr-Arg-Pro-Cys-Trp-Glu-Val with sequential elimination of substituents from both the carboxy- and amino-termini. All the analogues that contained tryptophan in position 15 were found to be full agonists and equipotent to MCH. In the absence of Trp15, full agonist activity was maintained but potency was reduced ten-fold or more. The minimal fragment analogue possessing equipotency to the parent peptide, MCH, was the MCH(5-15) sequence. These observations coupled with results from work reported previously by our laboratories suggest the importance of the Trp15 residue for interaction with the MCH receptor in this assay system.
Department of Chemistry, University of Arizona, Tucson 85721.
T O
TO
Matsunaga
A M
AM
Castrucci
M E
ME
Hadley
V J
VJ
Hruby
D000595:Amino Acid Sequence; D000818:Animals; D004524:Eels; D007028:Hypothalamic Hormones; D007202:Indicators and Reagents; D008543:Melanins / Q000138:chemical synthesis* / Q000494:pharmacology; D008547:Melanophores / Q000187:drug effects / Q000502:physiology*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis* / Q000494:pharmacology; D010907:Pituitary Hormones / Q000138:chemical synthesis* / Q000494:pharmacology; D013329:Structure-Activity Relationship
D007028:Hypothalamic Hormones; D007202:Indicators and Reagents; D008543:Melanins; D010446:Peptide Fragments; D010907:Pituitary Hormones; C019463:melanin-concentrating hormone