Blood-pressure-lowering peptide from snake venom (ACE inhibitor)
A peptide found in pit viper venom that blocks ACE, the enzyme that raises blood pressure, studied only in the lab, not yet an approved drug.
- Class
- Venom-derived ACE inhibitor peptide (bradykinin-potentiating peptide)
- Status
- Research peptide; no approved therapeutic status identified
- Best-supported effect
- ACE inhibitory activity characterized in structure-function assay studies (in vitro)
- Main caveat
- No animal or human efficacy data are present in this card's source file
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.
A chemistry service or a researcher ordered the sequence, it was manufactured, and mass spectrometry confirmed the right molecule was produced.
A binding or activity measurement confirmed that it actually does what the computer predicted — or didn't.
Snapshot
Class: Venom-derived ACE inhibitor peptide (bradykinin-potentiating peptide)
Evidence tier: In vitro / assay evidence
Status: Research peptide; no approved therapeutic status identified
Best-supported effect: ACE inhibitory activity characterized in structure-function assay studies (in vitro)
Main caveat: No animal or human efficacy data are present
What this is
This is an 11-residue peptide isolated from the venom of three pit viper species — the Chinese water moccasin (Agkistrodon halys pallas), the jararaca (Bothrops jararaca), and the jararacussu (Bothrops jararacussu). It belongs to the bradykinin-potentiating peptide (BPP) family, a class of venom-derived oligopeptides that inhibit angiotensin I-converting enzyme (ACE). The peptide carries a pyroglutamate (pGlu) N-terminal modification and a proline-rich backbone characteristic of ACE inhibitors from snake venom. One structure-function study in available literature characterizes this peptide's biochemical properties. No animal or human data are present in the attached available literature.
Evidence map
| Evidence layer | Grade | What it supports |
|---|---|---|
| Human | None identified | No human evidence identifieds available literature |
| Animal | None identified | No animal evidence identifieds available literature |
| In vitro | Weak | Structure-function characterization of ACE inhibitory activity; one 1985 study |
| Computational | None identified | No computational evidence identifieds available literature |
| Mechanism | Plausible | Proline-rich BPP scaffold with pGlu N-terminus consistent with ACE inhibitor class; mechanistic basis inferred from class membership |
Claim check
| Claim | Verdict | Evidence layer | Confidence |
|---|---|---|---|
| ACE inhibitory activity | Supported (in vitro) | In vitro | Medium — single 1985 structure-function study; independent replication not documented in source |
| Antihypertensive effect in humans | Not established | None | High — no human data present in available literature |
Assay conditions
This section reports conditions used in the structure-function study identifieds available literature. It does not establish animal or human exposure.
| Context | System | Assay condition | Timepoint | Endpoint | Limitation |
|---|---|---|---|---|---|
| Structure-function study | Biochemical / in vitro assay (snake venom peptide characterization) | Peptide structure variants; exact concentration not extracted | Not individually extracted | ACE inhibitory activity and structure-function relationship | Single study; conditions not fully extracted from source; no in vivo translation established |
Mechanism
This peptide belongs to the bradykinin-potentiating peptide (BPP) family, a group of ACE inhibitors originally identified in pit viper venoms. The proline-rich sequence — with a pyroglutamate at the N-terminus and multiple proline residues throughout the chain — is characteristic of this peptide class. ACE inhibitors in the BPP family are understood to bind the ACE active site and block conversion of angiotensin I to angiotensin II, thereby reducing vasoconstriction and potentiating bradykinin. The mechanistic basis is inferred from class membership and the 1985 structure-function study cited in available literature; direct receptor binding data for this specific sequence are not individually extracted.
Chemistry
| Field | Value |
|---|---|
| Notation | pGlu-GRPPGPPIPP |
| Amino-acid chain | pGlu-Gly-Arg-Pro-Pro-Gly-Pro-Pro-Ile-Pro-Pro-OH |
| Length | 11 amino acids |
| Topology | Linear |
| N-terminal modification | Pyroglutamate (pGlu) — cyclized glutamine/glutamate N-terminus |
| C-terminus | Free acid (-OH) |
| Sequence confidence | Needs review — single CU source; no cross-source sequence verification |
Regulatory status
No approved therapeutic status is identified in the attached available literature. This card describes a research or literature-derived peptide, not an approved medicine. Regulatory status for ACE inhibitor peptides from snake venom has not been extracted from available literature.
Open questions
- In vivo activity: No animal experiments are identifieds available literature. Whether ACE inhibitory activity observed in vitro translates to blood pressure or cardiovascular effects in any in vivo model is not established here.
- Human relevance: No human trial or observational data are present in available literature. Human-relevant ACE inhibition has not been characterized for this specific sequence.
- Sequence verification: The card relies on a single CU source for the sequence. Cross-source or primary literature verification of the exact sequence (especially the pGlu modification and C-terminal acid form) has not been performed for this card.
- Potency and selectivity: The 1985 source describes structure-function studies but detailed IC₅₀ or Ki values for ACE inhibition are not individually extracted.
- Comparison with approved ACE inhibitors: The relationship of this peptide's activity profile to approved small-molecule ACE inhibitors is not characterized in the attached source.
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 removing the chemical cap from the end of this snake-venom peptide make it much weaker at blocking the blood-pressure enzyme?
If true, drug researchers would know they must preserve or mimic that cap in any medicine based on this peptide, preventing years of wasted effort on the wrong version.
Do the two proline clusters in this peptide both need to be intact for it to work, or can one carry the load alone?
If both clusters are needed together, any shortened or simplified version of this peptide for a blood-pressure drug would need to keep both, saving chemists from pursuing dead-end truncations.
Does this peptide keep working to lower blood pressure even when the body finds a way around its main enzyme target?
If true, drugs based on this peptide could stay effective longer than current ACE inhibitors, which often lose their punch over time as the body adapts, benefiting patients with hard-to-control hypertension.
Could this peptide inhibit the neprilysin enzyme as well as the ACE enzyme it is already known to target?
If true, a drug based on this peptide could protect both the heart and kidneys at once, which is valuable for millions of patients with combined heart failure and kidney disease.
If this peptide were made into a circular ring shape, could it work as well as the naturally modified version without needing the tricky chemical cap?
If true, manufacturers could produce a simpler, cheaper version of this blood-pressure peptide that is also more stable in the body, making it more practical as a future medicine.
Does this peptide preferentially inhibit the N-terminal domain of ACE (linked to anti-scarring signals) over the C-terminal domain (linked to blood pressure)?
If true, a drug based on this peptide could reduce organ scarring in heart and kidney disease with a different side-effect profile from standard blood-pressure medicines.
▸full evidence table2 metrics
| metric | value | tool |
|---|---|---|
| ipTM | 0.3734199106693268 | boltz-2 |
| ranking score | 0.7420598864555359 | boltz-2 |
▸3-letter notation
▸recipeboltz-2 1.0
| parameter | value |
|---|---|
| model | boltz-2 1.0 |
| weights | — |
| hardware | nvidia_nim_api |
| mlx version | — |
| python | — |
| random seed | — |
| msa strategy | colabfold_nvidia |
| diffusion samples | 1 |
| runtime | — |
| predicted by | mlx@peptide |
| predicted at | 2026-04-25 |
▸citationbibtex
@peptide{pep10558,
sequence = {GRPPGPPIPP},
target = {ace},
author = {peptidemodel},
year = {2026},
status = {synthesized}
}