pe
pep-04717 v1 CC-BY-SA-4.0

Blood-pressure-lowering peptide (ISHIYVWK)

A small peptide that blocks ACE, an enzyme that raises blood pressure; studied as a possible treatment for high blood pressure, but still experimental and not an approved drug.

statusbioassayed targetACE length8 aa refs3
anti-hypertensive
EARLY ENTRY This candidate is newly indexed — supporting evidence is still being added. Have a paper or data point? Contribute below.
status 2 / 5 · 0 verified on platform
prediction metrics boltz-2 1.0
ipTM0.880
pTM0.679
avg pLDDT80.3
ranking score0.818
STRUCTURE · PEP-04717 × ACE
ranking0.818
target interface 4.5Å peptide drag rotate · ctrl+scroll zoom · right-click pan
boltz-2 1.0 · mmCIF ↓ download
sequence8 aa
158
ISHIYVWK
Hypotheses4 directions▾ collapse

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.

openupdated 2026-06-05

Could a simple chemical modification protect a natural peptide from being broken down in the gut before it does any good?

Many natural peptides that lower blood pressure never make it past the digestive tract in one piece. If this modification works, it could be a cheap, manufacturable way to turn a food-derived ingredient into a reliable functional food or supplement for people managing mild hypertension.

The hypothesis
N-terminal acetylation of ISHIYVWK increases its resistance to gastrointestinal aminopeptidases without reducing ACE inhibitory potency, because ACE inhibition by this peptide is driven by C-terminal residues and does not depend on the free N-terminal amine.
Why it’s plausible
Food-derived antihypertensive peptides face rapid N-terminal degradation by brush-border aminopeptidases in the gut before they can be absorbed intact. N-terminal acetylation is a well-established modification that blocks aminopeptidase cleavage of the first peptide bond (Ile1-Ser2 here) without adding charge or mass significantly. If ISHIYVWK's ACE-inhibitory pharmacophore resides primarily in the C-terminal VWK or YVWK region, blocking N-terminal degradation should preserve in vivo bioactivity while extending the peptide's half-life in the intestinal lumen. The existing literature explicitly flags in vivo activity as unconfirmed for this peptide.
Why it matters
Oral bioavailability is the single largest barrier preventing food-derived antihypertensive peptides from becoming functional food ingredients or nutraceuticals. A simple N-acetyl modification that preserves potency while improving gastrointestinal stability would be a low-cost, manufacturable solution applicable broadly to the ISHIYVWK scaffold.
Plausibility.70
Novelty.27
Impact.60
Basis · grounding2 papers · 1 computed/note
[1]
paper
Axis hit explicitly states that whether identified active peptides function in vivo is unclear and that bioavailability and metabolism of active peptides needs further study.
doi: 10.1038/s41598-021-84820-7
[2]
paper
Notes that ACE inhibitory peptides must reach the cardiovascular system in active form to lower blood pressure, underscoring the degradation problem.
doi: 10.1079/bjn20041189
[3]
sequenceN-terminus is Ile1, a bulky aliphatic residue that is a substrate for aminopeptidase N; acetylation would block this cleavage site. The pharmacophoric C-terminus (Trp7-Lys8) is unaffected by N-terminal modification.
openupdated 2026-06-05

Could this peptide do double duty, lowering blood pressure AND helping the heart handle fluid and stress better?

Drugs that block both of these pathways at once have shown stronger results in heart failure patients than single-target drugs alone. If this peptide turns out to share that mechanism, it could open a path toward a natural ingredient with broader cardiovascular benefit, not just blood pressure control.

The hypothesis
ISHIYVWK inhibits neprilysin (neutral endopeptidase, NEP/CD10) in addition to ACE, because its Tyr-Val-Trp-Lys C-terminal segment matches the hydrophobic cleavage preference of NEP, and dual ACE/NEP inhibition would give it a vasopeptidase inhibitor-like mechanism relevant to heart failure treatment beyond simple hypertension.
Why it’s plausible
Vasopeptidase inhibitors that simultaneously block ACE and NEP (e.g., omapatrilat) achieve synergistic blood-pressure lowering by preventing angiotensin II formation and preserving natriuretic peptides simultaneously. NEP preferentially cleaves on the N-terminal side of hydrophobic residues; the Tyr-Val-Trp sequence in ISHIYVWK presents multiple such cleavage-favored bonds. Short peptides with aromatic-rich sequences have been documented as NEP inhibitors in the food bioactive literature. If ISHIYVWK engages NEP's active-site zinc (Glu584, His583, His587 coordinating zinc) through its Trp or Tyr side chains, it could inhibit NEP at pharmacologically relevant concentrations.
Why it matters
Discovering dual ACE/NEP activity in ISHIYVWK would reframe it from a simple antihypertensive to a multi-target cardiovascular peptide with potential utility in heart failure, where preserved natriuretic peptide levels reduce cardiac fibrosis and fluid overload beyond blood-pressure lowering alone.
Plausibility.40
Novelty.62
Impact.70
Basis · grounding2 papers · 1 computed/note
[1]
sequenceISHIYVWK contains Tyr5-Val6-Trp7, a hydrophobic tripeptide segment compatible with NEP substrate preference for hydrophobic residues; His3 imidazole is a potential zinc-binding group for NEP active site.
[2]
paper
Review of food-derived antihypertensive peptides discusses multi-mechanism contributors to blood pressure but does not evaluate NEP inhibition for ISHIYVWK.
doi: 10.1021/acs.jafc.8b02603
[3]
paper
Notes that conventional antihypertensive drugs have side effects including rebound hypertension, motivating interest in multi-target peptides with complementary mechanisms.
doi: 10.1038/s41392-024-02107-5
openupdated 2026-06-05

Does one specific chemical feature of this peptide matter more than the rest for how well it works?

If a single hydroxyl group on one amino acid turns out to be critical, researchers could design stronger versions more precisely, instead of guessing. That kind of roadmap could speed up development of better food-derived ingredients for blood pressure management.

The hypothesis
The Tyr5 hydroxyl group of ISHIYVWK forms a hydrogen bond with a conserved ACE active-site residue (likely Tyr523 or Gln281 in the S1 subsite), and Tyr-to-Phe substitution at position 5 substantially reduces ACE inhibitory potency without changing the hydrophobic character of the peptide.
Why it’s plausible
ACE's S1 subsite contains Tyr523, which participates in substrate/inhibitor recognition through a hydrogen-bonding network. Tyr5 of ISHIYVWK is the third aromatic residue and is positioned centrally in the 8-mer. In peptide ACE inhibitor structure-activity relationships, the phenolic OH of Tyr has been shown to contribute specific hydrogen-bonding interactions that Phe cannot replicate, distinguishing the two residues in potency even when overall hydrophobicity is similar. The Tyr in AYFYPEL and YAEERYPIL long antihypertensive peptides has been implicated in active-site contacts.
Why it matters
Identifying Tyr5 as a specificity determinant via its hydroxyl group would guide engineering of more potent analogs, for instance by phosphotyrosine or sulfotyrosine substitution to modulate binding energy, and would clarify which aromatic residues in the sequence are load-bearing versus redundant.
Plausibility.50
Novelty.48
Impact.57
Basis · grounding1 paper · 2 computed/notes
[1]
sequenceTyr at position 5 of ISHIYVWK carries a para-hydroxyl group absent from Phe; it is positioned between Val4 and Trp7 in a hydrophobic stretch, making its hydroxyl group the only polar handle in the aromatic cluster.
[2]
paper
Review identifies Tyr and Trp as recurring features of potent antihypertensive peptides and notes that aromatic amino acids confer ACE inhibitory activity, but does not distinguish Tyr vs Phe contributions for ISHIYVWK.
doi: 10.1021/acs.jafc.8b02603
[3]
structureBoltz-2 complex at iPTM 0.88 implies a specific binding orientation that could position Tyr5 for active-site contacts with ACE.
openupdated 2026-06-05

Could this peptide target only the enzyme that raises blood pressure while leaving alone the one that protects the heart?

Some blood pressure compounds inadvertently hit a closely related enzyme that actually shields the heart from damage. If this peptide turns out to be selective, it would be a meaningfully safer profile than non-selective inhibitors, which matters most for people with existing heart conditions.

The hypothesis
ISHIYVWK inhibits ACE1 (somatic angiotensin-converting enzyme) selectively over ACE2, because its C-terminal Lys is bulky enough to clash with the ACE2 S1' pocket, which is narrower and favors small aliphatic residues.
Why it’s plausible
ACE1 and ACE2 share the zinc metallopeptidase fold but differ in substrate specificity: ACE1 is a dipeptidyl carboxypeptidase preferring substrates with penultimate Trp/Tyr, while ACE2 is a monocarboxypeptidase that cleaves C-terminal hydrophobic residues and disfavors C-terminal Lys. The C-terminal Lys of ISHIYVWK would be predicted to fit the ACE1 S1' pocket (which accommodates basic residues through the interaction with Glu384/Glu162) but to be excluded from the more constrained ACE2 S1' pocket. This selectivity matters because ACE2 is cardioprotective and its inhibition would be an undesirable side effect.
Why it matters
Confirming ACE1 selectivity over ACE2 would establish ISHIYVWK as a safer antihypertensive lead than non-selective zinc metalloprotease inhibitors, and would distinguish it from peptides that inadvertently inhibit ACE2 and potentially worsen cardiac remodeling.
Plausibility.38
Novelty.53
Impact.63
Basis · grounding2 papers · 1 computed/note
[1]
sequenceC-terminal Lys (basic, long side chain) is structurally mismatched with ACE2's S1' pocket, which strongly prefers hydrophobic C-terminal residues.
[2]
paper
Review notes that known antihypertensive peptides carry aromatic/proline features relevant to ACE1 specificity, but does not address ACE2 selectivity for ISHIYVWK specifically.
doi: 10.1021/acs.jafc.8b02603
[3]
paper
Antihypertensive activity attributed solely to ACE inhibitory mechanism without selectivity profiling against related zinc metalloproteinases.
doi: 10.1016/j.foodchem.2020.128719
details expand to inspect
full evidence table2 metrics
metricvaluetool
ipTM 0.8795640468597412 boltz-2
ranking score 0.8180637359619141 boltz-2
3-letter notation
Ile-Ser-His-Ile-Tyr-Val-Trp-Lys
recipeboltz-2 1.0
parametervalue
modelboltz-2 1.0
weights
hardwarenvidia_nim_api
mlx version
python
random seed
msa strategycolabfold_nvidia
diffusion samples1
runtime
predicted bymlx@peptide
predicted at2026-04-25
citationbibtex
peptidemodel (2026). Blood-pressure-lowering peptide (ISHIYVWK) (pep-04717, v1). PeptideModel. https://peptidemodel.com/card/pep-04717
@peptide{pep04717,
  sequence = {ISHIYVWK},
  target   = {ace},
  author   = {peptidemodel},
  year     = {2026},
  status   = {bioassayed}
}
related peptides 5 by signal overlap
references 3 papers
discussion no comments
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