Brain-signaling peptide fragment (PACAP-38 16-38)
A fragment of a natural brain hormone that switches on stress and pain pathways; studied for its role in PTSD-like fear responses, migraine, and allergic reactions, experimental, not an approved drug.
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
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Endogenous peptide fragment — receptor binding/activity established in published literature; CT.gov evidence
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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 this peptide go from unstructured to helical only after it contacts the receptor surface?
If confirmed, locking the peptide into its active shape chemically could make it far more potent. That principle could be applied to design better, longer-lasting drugs for conditions like migraine or neuroinflammation.
Could this short piece of PACAP bind the migraine-linked PAC1 receptor without turning it on, effectively blocking it?
It is already known that cutting off PACAP's very front end turns it into a receptor blocker, so this fragment could be a starting point for migraine drugs that quiet an overactive pathway. Whether this particular, more heavily trimmed fragment still binds well enough remains to be shown.
Does the positively charged tail of this peptide stick to the sugary coat on brain cells, keeping it close to where it needs to act?
Many positively charged peptides cling to these cell-surface sugars, so it is plausible this fragment does too, though this has not been shown for PACAP specifically. If it does, the stickiness could be tuned to extend how long the peptide stays near neurons.
Could this peptide be used as an address label to steer drugs into the specific brain cells that carry its receptor?
This depends on the fragment actually binding its receptor strongly enough to act as a targeting tag, which is not yet shown. If it does, it could help direct treatments into PAC1-bearing neurons and reduce off-target effects.
▸full evidence table2 metrics
| metric | value | tool |
|---|---|---|
| ipTM | 0.6740933060646057 | openfold3-mlx |
| ranking score | 0.7654287815093994 | openfold3-mlx |
▸structural qualityopenfold3
| metric | value | note |
|---|---|---|
| gpde | 0.877 | global PDE — lower = better |
| disorder | 0.193 | fraction disordered |
| chain pair ipTM (A, B) | 0.674 | 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 | 424s |
| 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{pep10629,
sequence = {QMAVKKYLAAVLGKRYKQRVKNK},
target = {pac1r},
author = {peptidemodel},
year = {2026},
status = {bioassayed}
}