pe
pep-10621 v1 CC-BY-SA-4.0

Neuromedin B-30: brain signaling peptide studied in pancreatic cancer

A natural brain and spinal-cord peptide involved in appetite, body temperature, and pain; reported at high levels in most pancreatic tumors; used as a lab research tool.

statussynthesized targetNTSR1 length30 aa refs3
snapshot sparse 10% confidence
Class
Neuropeptide fragment (bombesin family)
Status
No approved therapeutic status identified
Main caveat
Single vendor/catalog source only. No bioactivity, receptor binding, animal, or human evidence is attached to this card.
status 4 / 5
prediction metrics openfold3-mlx 0.3.1
ipTM0.633
pTM0.694
avg pLDDT58.1
ranking score0.796
STRUCTURE · PEP-10621 × NTSR1
ranking0.796
target interface 4.5Å peptide drag rotate · ctrl+scroll zoom · right-click pan
openfold3-mlx 0.3.1 · mmCIF ↓ download
sequence30 aa
151015202530
LSWDLPEPRSRAGKI RVHPRGNLWATGHFM
overview readme

What this is

Neuromedin B-30 (NMB-30) is a 30-residue neuropeptide found in the mammalian brain and spinal cord. It belongs to the bombesin family — a group of peptides named after an amphibian skin peptide (bombesin) whose mammalian counterparts regulate appetite, hormone release, body temperature, and emotional responses. NMB-30 is the larger precursor form of Neuromedin B, the well-characterized 10-residue decapeptide: NMB-30 contains the entire NMB sequence at its C-terminus, extended by 20 additional residues at the N-terminus. Like NMB itself, it activates the neuromedin B receptor (NMBR, also called the BB1 receptor), a G protein-coupled receptor expressed throughout the brain and in peripheral tissues. The C-terminus of NMB-30 carries an amide group (–NH₂) that is essential for receptor binding but is not visible in the stored 1-letter sequence.

History

Neuromedin B, the 10-residue core peptide, was first identified from porcine spinal cord in 1983 by Minamino and colleagues, who noted its striking sequence similarity to the amphibian peptide bombesin and its potent smooth-muscle-stimulating activity. Two years later, the same group returned to porcine brain and spinal cord extracts and isolated two larger, N-terminally extended relatives: Neuromedin B-32 (32 residues) and Neuromedin B-30 (30 residues). Minamino and colleagues (1985) described NMB-30 as a two-amino-acid N-terminal deletion of NMB-32, with all three forms — NMB, NMB-30, and NMB-32 — constituting a biosynthetic family derived from a common precursor through sequential enzymatic processing. This isolation, reported in Biochemical and Biophysical Research Communications, established NMB-30 as a naturally occurring molecular form present in the mammalian central nervous system, not merely a synthetic fragment.

What it does

Neuromedin B-30 carries the full pharmacological activity of the NMB family at its C-terminal decapeptide end, which is the sequence that engages the NMBR/BB1 receptor. Through this receptor, NMB and its extended forms exert a range of effects documented across tissue and species studies. In the brain, NMB-family peptides act within the central amygdala to modulate fear and cardiovascular responses: injection into the central lateral amygdala excites neurons via BB1 receptors and alters fear-potentiated startle responses (Bhatt and colleagues 2023). In the pituitary, NMB functions as a paracrine/autocrine inhibitor of thyroid-stimulating hormone (TSH) secretion — pituitary thyrotroph cells produce their own NMB, and disruption of NMBR signaling impairs the ability of the thyrotroph to mount a TSH response during hypothyroidism (Kanasaki and colleagues 2006). NMB also influences appetite through peripheral satiety pathways that are distinct from those used by its cousin gastrin-releasing peptide (GRP). Additional roles documented in the literature include smooth muscle contraction in the gastrointestinal and urogenital tracts, regulation of blood pressure and body temperature, and stimulation of exocrine and endocrine secretions. In several cancer cell lines, NMB acts as an autocrine growth factor: it binds NMBR on small cell lung cancer cells, elevates intracellular calcium, and stimulates proliferation; NMBR also cross-activates the EGF receptor in non-small cell lung cancer cells.

Evidence

  • Human: No clinical trials have evaluated Neuromedin B-30 directly. The broader NMB/NMBR system has been characterised in human tissues, and NMBR overexpression has been documented in human lung cancer cell lines and other tumors. No registered trials on ClinicalTrials.gov for "Neuromedin B-30."
  • Animal: The 1985 isolation paper by Minamino and colleagues demonstrated that NMB-30 is an authentic mammalian neuropeptide present in porcine brain and spinal cord, sharing biosynthetic origin with NMB-32 and the decapeptide NMB. Rodent studies using NMB (which shares the active C-terminal pharmacophore with NMB-30) showed: NMBR-knockout mice display dysregulation of the pituitary-thyroid axis (Kanasaki and colleagues 2006); NMB injection into the central amygdala modulates cardiovascular output and fear-potentiated startle in rats (Bhatt and colleagues 2023).
  • In vitro: NMB binds with high affinity to NMBR on small cell lung cancer cell lines, elevating cytosolic calcium in a concentration-dependent manner; these responses are blocked by NMBR-selective antagonists.

Known effects

  • Fear and startle modulation — Preclinical (rat): BB1 receptor activation in the central lateral amygdala alters fear-potentiated startle and cardiovascular output
  • TSH regulation — Preclinical (mouse): NMB/NMBR system modulates the pituitary-thyroid axis set point; NMBR-knockout mice show impaired TSH responses during hypothyroidism
  • Smooth muscle contraction — Preclinical (rat uterus): original 1983 pharmacology of NMB family; active at bombesin receptors
  • Appetite/satiety signaling — Preclinical: NMB mediates satiety via peripheral pathways distinct from those of GRP/BB2
  • Tumor cell proliferation — In vitro: autocrine growth stimulation in small cell and non-small cell lung cancer cell lines via NMBR; also expressed in human pancreatic cancer cell lines

Mechanism

NMB-30 acts as an agonist at NMBR (BB1), a seven-transmembrane class A GPCR that shows more than 100-fold higher affinity for NMB-family peptides than for GRP-family peptides. The receptor couples to Gq/11, activating phospholipase C, generating IP₃ and diacylglycerol, mobilising intracellular calcium, and activating protein kinase C. In amygdala neurons, BB1 signalling additionally inhibits GIRK channels via a phospholipase Cβ–PKC pathway, increasing neuronal firing frequency (Bhatt and colleagues 2023). In lung cancer cells, NMBR transactivates the EGF receptor through BB1-initiated intracellular cascades, coupling bombesin-family signalling to mitogenic EGF pathway outputs. The pharmacophore driving receptor activation resides in the C-terminal heptapeptide — shared across NMB, NMB-30, and NMB-32 — explaining why the extended forms retain the same biological activity as the decapeptide.

Safety signals

No human safety data exist for Neuromedin B-30. It is a research peptide with no regulatory filings or published preclinical toxicology packages. All functional data derive from animal studies or cell-line experiments.

Regulatory status

  • US (FDA): Not approved. No clinical use.
  • EU (EMA): Not approved.
  • WADA: Not listed on the Prohibited List.
  • Research use: Synthetic NMB-30 is available from commercial peptide suppliers as a research-grade reagent.

Related peptides

  • Neuromedin B (NMB) — the 10-residue C-terminal core peptide; the primary agonist at NMBR/BB1; NMB-30 and NMB-32 are its N-terminally extended precursor relatives
  • Neuromedin B-32 — the 32-residue form isolated alongside NMB-30 by Minamino and colleagues (1985); NMB-30 is a two-amino-acid N-terminal deletion of NMB-32
  • Gastrin-releasing peptide (GRP) — the other major mammalian bombesin-family peptide; activates the GRP receptor (GRPR/BB2) rather than BB1; the two systems share structural homology but distinct receptor selectivity and physiological roles
Hypotheses3 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

Does NMB-30 actually engage the neurotensin receptor, or is that annotation a database error?

If the target label is wrong, researchers chasing an NMB-30/neurotensin-receptor drug lead are working on a false premise. Correcting it could save years of misdirected effort in pancreatic cancer programs.

The hypothesis
The annotated NTSR1 target for NMB-30 is likely incorrect or secondary: the peptide's primary receptor is NMBR (BB1), and the low ipTM (0.633) reflects poor structural complementarity with NTSR1 rather than genuine NMB-30/neurotensin-receptor engagement.
Why it’s plausible
NMB-30 contains the full 10-residue NMB sequence at its C-terminus (GNLWATGHFM), which is the established NMBR-binding pharmacophore from the bombesin family. Neurotensin receptors bind the unrelated sequence RRPYIL at their C-terminus. The openfold3-mlx ipTM of 0.633 with NTSR1 is borderline-poor for a confident cognate-receptor complex, consistent with a docking mismatch rather than a true interaction.
Why it matters
If NMB-30 does not engage NTSR1 in physiological settings, then any cancer or CNS biology attributed to an NMB-30/NTSR1 axis would be artifactual, redirecting drug-design efforts back to NMBR.
Plausibility.90
Novelty.55
Impact.75
Basis · grounding3 computed/notes
[1]
sequenceC-terminal 10 residues GNLWATGHFM match the canonical NMB decapeptide, the established NMBR pharmacophore
[2]
structureopenfold3-mlx/complex ipTM=0.633 with NTSR1 is below the confident-complex threshold, suggesting poor structural fit
[3]
noteREADME explicitly states NMB-30 activates NMBR (BB1 receptor); NTSR1 is a neurotensin receptor with unrelated endogenous ligand
openupdated 2026-06-05

Could we replace the useless N-terminal section of NMB-30 with a tumor-homing sequence to create a peptide that attacks cancer from two directions at once?

Dual-targeting peptides can kill cancer cells more efficiently than single-target agents, and this approach uses an existing natural scaffold rather than building from scratch, potentially shortening the path to a clinical candidate.

The hypothesis
Replacing the disordered N-terminal 20 residues of NMB-30 with a tumor-homing sequence (e.g., an RGD-containing or EGFR-binding motif) while retaining the NMBR-binding C-terminal decapeptide would create a bispecific peptide that co-engages an integrin or growth-factor receptor alongside NMBR, achieving synergistic anti-tumor activity in NMBR-overexpressing cancers.
Why it’s plausible
The N-terminal extension has no established receptor of its own (it is a biosynthetic pro-sequence), making it available for re-engineering without displacing a natural binding interaction. The C-terminal NMB pharmacophore is well defined and tolerant of N-terminal modifications in related bombesin analogues used in PET imaging. Bispecific peptides engaging two surface receptors can achieve cooperative tumor cell killing at lower individual receptor occupancy.
Why it matters
Bispecific bombesin-family peptides are an active area in oncology imaging and targeted therapy; NMB-30's natural bifunctional architecture (inactive N-arm plus active C-terminus) provides a blueprint that nature already validated as a single expressed polypeptide.
Plausibility.60
Novelty.65
Impact.65
Basis · grounding3 computed/notes
[1]
noteN-terminal 20 residues are a biosynthetic extension removed during processing to yield active NMB; they have no defined cognate receptor
[2]
sequenceC-terminal GNLWATGHFM is the intact NMB pharmacophore confirmed to activate NMBR
[3]
structurepLDDT=58.1 for the full complex suggests the N-terminal arm is disordered and unlikely to clash sterically with a grafted targeting sequence
openupdated 2026-06-05

Does the longer precursor form of NMB activate the same downstream signals as the short processed form, or does the extra sequence change which signals fire?

If NMB-30 and NMB trigger different cellular programs, drugs that mimic or block one form could have more targeted effects, for example suppressing appetite without triggering the side effects tied to the other signaling arm.

The hypothesis
The 20-residue N-terminal extension of NMB-30 (LSWDLPEPRSRAGKIRVHPR) acts as an allosteric modulator of NMBR signaling, biasing receptor coupling toward a distinct G-protein or arrestin pathway compared to the processed 10-residue NMB core.
Why it’s plausible
Biosynthetic processing converts NMB-30 into NMB at sites of action; if processing is incomplete or regionally variable, the N-terminal extension persists and contacts receptor surfaces not engaged by the decapeptide alone. N-terminal extensions in related bombesin-family peptides (e.g., NMB-32 vs. NMB-30) alter potency and selectivity profiles. Biased agonism at bombesin-family GPCRs has been documented for structurally modified analogues (10.1126/sciadv.abe5504), suggesting the receptor can adopt multiple active conformations.
Why it matters
A bias-inducing N-terminal tail would mean NMB-30 and NMB produce qualitatively different physiological signals even at the same receptor, with implications for appetite regulation and tumor growth driven by autocrine NMBR signaling.
Plausibility.55
Novelty.70
Impact.60
Basis · grounding3 computed/notes
[1]
sequenceResidues 1-20 (LSWDLPEPRSRAGKIRVHPR) are absent from processed NMB; KIRV contains a basic patch that could engage extracellular receptor loops
[2]
noteNMB-30, NMB-32, and NMB constitute a biosynthetic family from sequential enzymatic processing, implying partial-processing intermediates exist in tissue
[3]
sourceStructural studies on related GPCR ligands show extracellular loop contacts influence signaling bias
details expand to inspect
full evidence table2 metrics
metricvaluetool
ipTM 0.633167564868927 openfold3-mlx
ranking score 0.7961580753326416 openfold3-mlx
structural qualityopenfold3
0
metricvaluenote
gpde0.709global PDE — lower = better
disorder0.302! high disorder
chain pair ipTM (A, B)0.633interface quality
3-letter notation
Leu-Ser-Trp-Asp-Leu-Pro-Glu-Pro-Arg-Ser-Arg-Ala-Gly-Lys-Ile-Arg-Val-His-Pro-Arg-Gly-Asn-Leu-Trp-Ala-Thr-Gly-His-Phe-Met
recipeopenfold3-mlx 0.3.1
parametervalue
modelopenfold3-mlx 0.3.1
weightsaedd8f3eb814e392…
hardwareapple_m4_base_16gb
mlx version0.31.1
python3.14.3
random seed42
msa strategycolabfold
diffusion samples1
runtime355s
predicted bymlx@peptide
predicted at2026-04-25
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
peptidemodel (2026). Neuromedin B-30: brain signaling peptide studied in pancreatic cancer (pep-10621, v1). PeptideModel. https://peptidemodel.com/card/pep-10621
@peptide{pep10621,
  sequence = {LSWDLPEPRSRAGKIRVHPRGNLWATGHFM},
  target   = {ntsr1},
  author   = {peptidemodel},
  year     = {2026},
  status   = {synthesized}
}
related peptides 2 by signal overlap
clinical trials 0 trials · checked 2026-05-09
0
no registered clinical trials as of 2026-05-09; we'll re-check periodically
references 3 papers
discussion no comments
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