Potent Opioid Peptide Agonists Containing 4′‐[<i>N</i>‐((4′‐phenyl)‐phenethyl)carboxamido]phenylalanine (Bcp) in Place of Tyr
Bibliographic record
Abstract
Analogues of the opioid peptides H-Tyr-c[D-Cys-Gly-Phe(pNO2)-D-Cys]NH2 (non-selective), H-Tyr-D-Arg-Phe-Lys-NH2 (mu-selective) and dynorphin A(1-11)-NH2 (kappa-selective) containing 4'-[N-((4'-phenyl)-phenethyl)carboxamido]phenylalanine (Bcp) in place of Tyr1 were synthesized. All three Bcp1-opioid peptides retained high mu opioid receptor binding affinity, but showed very significant differences in the opioid receptor selectivity profiles as compared with the corresponding Tyr1-containing parent peptides. The cyclic peptide HBcp-c[D-Cys-Gly-Phe(pNO2)-D-Cys]NH2 turned out to be an extraordinarily potent, mu-selective opioid agonist, whereas the Bcp1-analogue of dynorphin A(1-11)-NH2 displayed partial agonism at the mu receptor. The obtained results suggest that the large biphenylethyl substituent contained in these compounds may engage in a hydrophobic interaction with a receptor subsite and thereby may play a role in the ligand's ability to induce a specific receptor conformation or to bind to a distinct receptor conformation in a situation of conformational receptor heterogeneity.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".