pe
pep-04597 v1 CC-BY-SA-4.0

αs1-casein blood-pressure peptide

A natural peptide fragment that blocks ACE, the enzyme that raises blood pressure, helping to lower it; used only as a lab research tool.

statusbioassayed targetACE length11 aa refs13
angiotensin-converting-enzyme-ace-inhibitorsanti-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
ipTM0.591
pTM0.479
avg pLDDT78.2
ranking score0.743
STRUCTURE · PEP-04597 × ACE
ranking0.743
target interface 4.5Å peptide drag rotate · ctrl+scroll zoom · right-click pan
boltz-2 1.0 · mmCIF ↓ download
sequence11 aa
151011
FVAPFPEVFGK
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 natural peptide from milk block blood pressure in a smarter, more targeted way than standard medications?

Common ACE-inhibitor drugs (like lisinopril) trigger a persistent dry cough in roughly 1 in 5 users because they block two related enzymes at once. If this peptide turns out to target only the one enzyme responsible for blood pressure control, it could offer a gentler option for the millions of people who stop taking their medication because of that cough.

The hypothesis
FVAPFPEVFGK selectively inhibits the C-domain of ACE over the N-domain, giving it a blood-pressure-lowering profile that avoids interference with bradykinin metabolism and the cough side-effect associated with N-domain activity.
Why it’s plausible
Human ACE has two catalytic domains (N and C) with partially distinct substrate specificity; captopril and lisinopril inhibit both, causing bradykinin accumulation that drives cough. Several food-derived peptides show domain selectivity correlated with their C-terminal residue and the depth of hydrophobic insertion into the S2' subsite. FVAPFPEVFGK ends in GK, a combination that structurally differs from the classical C-domain-selective pharmacophore, but the two flanking phenylalanines and the double-proline motif could preferentially fit the larger hydrophobic cleft of the C-domain. This is testable via domain-specific ACE assays and is non-trivial because most food peptides are not assessed for domain selectivity.
Why it matters
C-domain selective inhibition would give the peptide a favorable safety advantage over non-selective ACE inhibitors derived from the same food source, improving its translational potential as a functional food or nutraceutical ingredient.
Plausibility.50
Novelty.72
Impact.72
Basis · grounding2 papers · 1 computed/note
[1]
sequenceC-terminal GK and dual-proline arrangement may fit C-domain selectivity criteria based on structural analogy to characterized domain-selective inhibitors
[2]
paper
Review notes that aromatic and proline residues are key features of potent ACE-inhibitory peptides; domain selectivity not reported for this sequence
doi: 10.1021/acs.jafc.8b02603
[3]
paper
Review of natural antihypertensive peptides discusses pharmacokinetic and selectivity considerations as a key gap
doi: 10.13005/bbra/3410
openupdated 2026-06-05

What if a food peptide helps your blood pressure by changing what lives in your gut, not by blocking an enzyme?

If this mechanism holds, the peptide would work through a completely different route than any current blood pressure drug, potentially explaining why benefits in studies appeared slowly and lasted longer. For people looking for a food-based or probiotic-friendly approach to blood pressure support, that would open a genuinely new door.

The hypothesis
The antihypertensive effect of FVAPFPEVFGK in vivo is partly independent of ACE inhibition and instead involves modulation of gut microbiota composition that raises circulating short-chain fatty acid levels, lowering blood pressure through GPR41/GPR43 signaling.
Why it’s plausible
A double-blind RCT with a formulation containing FFVAPFPEVFGK (the one-residue longer form) demonstrated blood pressure reduction accompanied by reshaping of gut microbiota. The parent αs1-casein peptides RYLGY and AYFYPEL exert antihypertensive effects via opioid receptors naloxone-reversibly, establishing precedent for non-ACE mechanisms within this protein family. FVAPFPEVFGK reaches the colon partially intact after oral dosing (proline-containing peptides resist brush-border peptidases), where it could act as a prebiotic substrate or direct modulator of bacteria that produce butyrate and propionate, ligands for the blood-pressure-relevant receptors GPR41 and GPR43.
Why it matters
If a gut-microbiota pathway contributes independently, the peptide has a distinct mechanism from synthetic ACE inhibitors, opening a route for combination with probiotics and explaining the delayed, sustained antihypertensive effect observed in animal and clinical studies.
Plausibility.47
Novelty.63
Impact.68
Basis · grounding3 papers
[1]
paper
Clinical RCT with hydrolysate containing FFVAPFPEVFGK showed blood pressure lowering correlated with gut microbiota reshaping
doi: 10.1038/s41598-025-98446-6
[2]
paper
αs1-casein peptide antihypertensive effect in SHR found to be mediated by opioid receptors, not solely ACE inhibition
doi: 10.1021/acs.jafc.9b03872
[3]
paper
αs1-casein f(23-34) FFVAPFPGVFGK confirmed antihypertensive in vivo, active form may differ from in vitro sequence
doi: 10.1021/acs.jafc.8b02603
openupdated 2026-06-05

Does this peptide get destroyed in your stomach before it can do anything useful, or does enough survive to matter?

Most peptides are broken down in the gut before they can reach the bloodstream, which limits them to local effects. If this one makes it through largely intact, it could potentially be developed as an oral supplement or even a drug, rather than being limited to food and probiotic applications. That distinction shapes the entire development path.

The hypothesis
FVAPFPEVFGK survives gastric and small-intestinal proteolysis sufficiently intact to reach the systemic circulation and exert ACE inhibition in vivo, rather than acting only luminally or through released di/tripeptide fragments.
Why it’s plausible
The oral-bioavailability axis hits (score 0.687) reference data showing that αs1-casein antihypertensive peptides can be absorbed through intestinal epithelium. Proline-containing peptides are inherently resistant to most endopeptidases and brush-border exopeptidases because the imino nitrogen of proline blocks cleavage. FVAPFPEVFGK contains two prolines that flank the central residues, potentially shielding the peptide from sequential exopeptidase attack from both ends. The RCT with the closely related FFVAPFPEVFGK showed systemic blood-pressure reduction, consistent with at least partial intact absorption. This is distinct from a scenario in which the peptide is fully degraded to free amino acids before exerting effect.
Why it matters
Demonstrating systemic intact absorption would qualify FVAPFPEVFGK for drug-like development pathways and oral bioavailability optimization, whereas a purely luminal mechanism would limit it to probiotic/food applications.
Plausibility.55
Novelty.38
Impact.73
Basis · grounding2 papers · 1 computed/note
[1]
paper
RCT with formulation containing FFVAPFPEVFGK produced systemic blood pressure reduction, implying at least partial intact absorption or a systemically acting breakdown product
doi: 10.1038/s41598-025-98446-6
[2]
paper
Casein antihypertensive peptides shown to be absorbed through in vitro intestinal epithelium model
doi: 10.1021/acs.jafc.0c07048
[3]
sequenceTwo prolines at positions 4 and 6 create structural resistance to exopeptidase attack, supporting partial survival through GI transit
openupdated 2026-06-05

Could one naturally occurring peptide do the job of two different blood pressure medications at the same time?

A drug called sacubitril/valsartan already proves that blocking two specific enzymes together lowers blood pressure better than blocking just one, but it is a prescription combination drug. If this milk peptide could do something similar on its own, it might one day offer a food-derived ingredient with an amplified effect and a naturally low toxicity profile. This is speculative: no one has tested this peptide against the second enzyme yet.

The hypothesis
FVAPFPEVFGK inhibits neprilysin (NEP/CD10), a zinc metalloprotease structurally related to ACE that degrades natriuretic peptides, such that dual ACE/NEP inhibition by this single peptide amplifies blood pressure reduction beyond what ACE inhibition alone can achieve.
Why it’s plausible
Neprilysin and ACE are both zinc-dependent metalloproteases and share pharmacophore requirements: C-terminal hydrophobic residues and zinc-chelating groups favor inhibition of both enzymes. The clinical success of the dual ACE/NEP inhibitor omapatrilat and the ARB/NEP-inhibitor combination sacubitril/valsartan establishes that dual blockade is therapeutically superior. FVAPFPEVFGK contains a C-terminal K whose epsilon-amino group could coordinate zinc at the NEP active site analogously to its putative ACE binding. No study has tested this peptide against NEP, and the structural homology between the two proteases makes this a plausible but unverified hypothesis.
Why it matters
If validated, FVAPFPEVFGK would be a single-molecule functional analog of dual-acting antihypertensive drugs, with the additional advantage of being a naturally occurring food-derived peptide with an inherently low toxicity expectation.
Plausibility.35
Novelty.68
Impact.75
Basis · grounding2 papers · 1 computed/note
[1]
sequenceC-terminal K and hydrophobic core (F, V, F) shared with pharmacophores that inhibit zinc metalloproteases including NEP
[2]
paper
Review of food-derived antihypertensive peptides notes that some sequences active against ACE have untested potential against related zinc proteases
doi: 10.1021/acs.jafc.8b02603
[3]
paper
Natural antihypertensive peptide review identifies gaps in target coverage, including lack of NEP data for casein-derived sequences
doi: 10.13005/bbra/3410
details expand to inspect
full evidence table2 metrics
metricvaluetool
ipTM 0.59074866771698 boltz-2
ranking score 0.7434992790222168 boltz-2
structural qualityopenfold3
metricvaluenote
gpde2.073global PDE — lower = better
disorderNaNfraction disordered
3-letter notation
Phe-Val-Ala-Pro-Phe-Pro-Glu-Val-Phe-Gly-Lys
recipeboltz-2 1.0
parametervalue
modelboltz-2 1.0
weights
hardwarenvidia_nim_api
mlx version
python
random seed
msa strategynone
diffusion samples1
runtime
predicted bymlx@peptide
predicted at2026-04-24
citationbibtex
peptidemodel (2026). αs1-casein blood-pressure peptide (pep-04597, v1). PeptideModel. https://peptidemodel.com/card/pep-04597
@peptide{pep04597,
  sequence = {FVAPFPEVFGK},
  target   = {ace},
  author   = {peptidemodel},
  year     = {2026},
  status   = {bioassayed}
}
related peptides 5 by signal overlap
references 13 papers
[1]
Angiotensin-converting enzyme inhibitory activity in Mexican Fresco cheese
Torres-Llanez M; González-Córdova A; Hernandez-Mendoza A; Garcia H; Vallejo-Cordoba B Journal of Dairy Science 2011
source scaffold
[6]
Critical Review and Perspectives on Food-Derived Antihypertensive Peptides
Miralles, B. et al. Journal of Agricultural and Food Chemistry 2018
supporting
[12] supporting
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