PTSD and migraine brain-receptor blocker (PACAP-27 fragment 6-27)
A lab-made fragment of a stress-signaling protein that blocks a brain receptor linked to fear, PTSD-like responses, and migraine; used only as a lab research tool.
A researcher, an agent, or an algorithm wrote down the sequence and picked a target to hit.
An AI model like OpenFold3 or AlphaFold built a 3D structure and scored how well it fits the binding site.
A second contributor repeated the computation on their own hardware and the scores matched.
Named peptide fragment — synthesized for research; ClinicalTrials.gov trials registered for parent compound or class
Fork this card to add platform evidence →
Endogenous peptide fragment — receptor binding/activity established in published literature; CT.gov evidence
Fork this card to add platform evidence →
Research directions for this peptide, selected from the current sources — hypotheses you can explore and model. None of it is proven yet; tap any one to see the full thinking.
Does the peptide grab the receptor surface through an initial electrical attraction before snapping into its final shape?
Understanding exactly how the peptide attaches could let researchers engineer versions that stay bound longer or shorter as needed, which matters for building drugs with the right duration of action for PTSD or migraine treatment.
Does removing the first five amino acids of PACAP-27 turn a receptor activator into a receptor blocker?
This mirrors how other N-terminally shortened PACAP fragments are already known to bind the receptor without activating it. If it holds for this fragment, it could support development of a PTSD or migraine drug that blocks the overactive receptor instead of switching it on, though that link to disease is still unproven.
Would chemically locking the tail of this peptide into a ring make it bind tighter and survive longer in the body?
Helix-locking by cyclization is a proven way to boost peptide stability and binding for related molecules. If it works here, it could turn this short peptide into a more drug-like candidate, though the exact ring chemistry and its effect on this fragment still need testing.
Is the short hydrophobic tail (KYLAAVL) a major part of what grips the receptor?
If the tail contributes most of the binding, chemists might build a much shorter, cheaper peptide that is easier to deliver to the brain. The central basic stretch likely still adds some binding strength, so it may not be a pure spacer.
▸full evidence table2 metrics
| metric | value | tool |
|---|---|---|
| ipTM | 0.7746410369873047 | openfold3-mlx |
| ranking score | 0.8522644639015198 | openfold3-mlx |
▸structural qualityopenfold3
| metric | value | note |
|---|---|---|
| gpde | 0.830 | global PDE — lower = better |
| disorder | 0.192 | fraction disordered |
| chain pair ipTM (A, B) | 0.775 | interface quality |
▸3-letter notation
▸recipeopenfold3-mlx 0.3.1
| parameter | value |
|---|---|
| model | openfold3-mlx 0.3.1 |
| weights | aedd8f3eb814e392… |
| hardware | apple_m4_base_16gb |
| mlx version | 0.31.1 |
| python | 3.14.3 |
| random seed | 42 |
| msa strategy | colabfold |
| diffusion samples | 1 |
| runtime | 417s |
| predicted by | mlx@peptide |
| predicted at | 2026-04-23 |
python3 openfold3/run_openfold.py predict --query_json {query.json} --runner_yaml examples/example_runner_yamls/mlx_runner.yml --output_dir {output_dir} --num_diffusion_samples 1 ▸citationbibtex
@peptide{pep10546,
sequence = {FTDSYSRYRKQMAVKKYLAAVL},
target = {pac1r},
author = {peptidemodel},
year = {2026},
status = {bioassayed}
}