Cyclic penicillamine containing enkephalin analogs display profound delta receptor selectivities

Henry I. Mosberg, Robin Hurst, Victor J. Hruby, Kelvin Gee, Kazufumi Akiyama, Henry I. Yamamura, James J. Galligan, Thomas F. Burks

Research output: Contribution to journalArticlepeer-review

55 Scopus citations


The cyclic, penicillamine (β, β dimethylcysteine)-containing enkephalin analogs, [D-Cys2, L-Pen5]- and [D-Cys2, D-Pen5]enkephalin and the corresponding bis-penicillamine analogs, [D-Pen2, L-Pen5]- and [D-Pen2, D-Pen5]enkephalin were synthesized and evaluated for opioid activity in the guinea pig ileum (GPI) and mouse vas deferens (MVD) bioassays and in rat brain and neuroblastoma-glioma cell membrane binding assays. These analogs all displayed δ receptor selectivity as assessed by IC50(GPI)/IC50(MVD) ratios and by their relative potencies for displacing [3H]naloxone (NAL) vs. [3H] [D-Ala2, D-Leu5]enkephalin (DADLE) from rat brain membrane preparations. For [D-Pen2, L-Pen5]- and [D-Pen2, D-Pen5]enkephalinthe observed IC50(GPI)/IC50 (MVD) ratios (1088 and 3164) and IC50NAL/IC50DADLE ratios (371 and 175) represent a vast improvement over previously reported δ receptor selective ligands.

Original languageEnglish (US)
Pages (from-to)447-450
Number of pages4
JournalLife Sciences
Issue numberSUPPL. 1
StatePublished - 1983

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Pharmacology, Toxicology and Pharmaceutics(all)


Dive into the research topics of 'Cyclic penicillamine containing enkephalin analogs display profound delta receptor selectivities'. Together they form a unique fingerprint.

Cite this