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Linaclotide / Studies
Synthetic analog · 14 amino acids · 1,526.8 Da

Linaclotide studies and research data

PepBank has 66 linaclotide studies with results. 65 of them gave linaclotide, with 389 results, grouped by what the studies measured. In each group, results from studies in people come first. Data as of 2026-10-30.

Searches 389 results and 250 papers. Newer studies from Europe PMC

Results in people
294
76% of 389 results
Results in animals
70
18% of 389 results
Results in lab cells
25
6% of 389 results
From computer models
0
0% of 389 results
The molecule

Linaclotide identity

Identifiers, parent molecule, targets and development stage, from curated data.

Linaclotide is a 14-residue peptide with three disulfide bridges. It activates guanylate cyclase-C on the luminal surface of intestinal epithelial cells. Its labeled indications concern constipation disorders.

Kind
Synthetic analog · 14 residues
Identifiers
ChEMBLCHEMBL3301675 (opens in a new tab)PubChem CID16158208 (opens in a new tab)UNIIN0TXR0XR5X (opens in a new tab)DrugBankDB08890 (opens in a new tab)CAS851199-59-2
Development
Approved in the US and EU (Linzess, 2012)An approved medicinal product exists. Availability and other indications can differ. Source (opens in a new tab)

Targets

Molecular targets with action and evidence source
TargetActionEvidence
Guanylate cyclase CGUCY2CP25092 (opens in a new tab)AgonistOfficial prescribing information, mechanism of actionSource (opens in a new tab)

Sequence and structure

Residues, differences from the parent, calculated properties and 3D structure. Source values and calculated values are shown separately.

Sequence

14 amino acids · 3 disulfide bonds

H-
Residues 1 to 10:
CCEYCCNPAC
Residues 11 to 14:
TGCY
-OH
  • HydrophobicA V I L M
  • AromaticF W Y
  • NegativeD E
  • PolarS T N Q
  • SpecialC G P
  • Disulfide partner

Modifications

Cys5–Cys13
Disulfide bond
Cys2–Cys10
Disulfide bond
Cys1–Cys6
Disulfide bond

Properties

From identity sources

Formula
C59H79N15O21S6
Molecular weight
1,526.8 g/mol
Monoisotopic mass
1,525.3899 Da

Calculated from the sequence

Average mass
1,526.72 Da
Sum of ExPASy residue masses + water + 3 disulfides · ExPASy Compute pI/Mw; FindMod
Monoisotopic mass
1,525.3899 Da
Sum of ExPASy residue masses + water + 3 disulfides · ExPASy FindMod
Isoelectric point (pI)
3.85
pH of zero net charge, EMBOSS pKa set · EMBOSS iep, Epk.dat
Net charge at pH 7.4
−1.06
Henderson-Hasselbalch, EMBOSS pKa set · EMBOSS iep, Epk.dat
GRAVY (hydropathy)
0.321
Mean Kyte-Doolittle hydropathy · Kyte and Doolittle 1982
Positive: hydrophobic on average.
Extinction coefficient, 280 nm (Cys reduced)
2,980 M⁻¹ cm⁻¹
5500 x Trp + 1490 x Tyr · Pace et al. 1995 (ExPASy ProtParam)
No Trp: ExPASy reports more than 10 % error without Trp.
Extinction coefficient, 280 nm (all Cys as cystines)
3,355 M⁻¹ cm⁻¹
5500 x Trp + 1490 x Tyr + 125 x cystine · Pace et al. 1995 (ExPASy ProtParam)
Instability index
69.59
Dipeptide instability weights (DIWV) · Guruprasad et al. 1990
Above 40: classed as possibly unstable (ExPASy).
Aliphatic index
7.1
Mole % A + 2.9 V + 3.9 (I + L) · Ikai 1980
Boman index
0.42 kcal/mol
Mean solubility value (negated) · Boman 2003
2.48 or below: lower protein-binding potential (Boman).
Hydrophobic moment (μH)
0.240
Eisenberg scale, 100° per residue, best 11-residue window · Eisenberg et al. 1982, 1984
pI with each pKa set
EMBOSS 3.85Bjellqvist (ExPASy) 4.00IPC peptide 3.35IPC protein 3.64
  • Defined and validated for proteins; use with care for short peptides.
  • Assumes an ideal alpha helix. Many short peptides are not helical.

@pepdb/chem 0.2.0 · EMBOSS pKa set · ExPASy residue masses

Net charge by pH

pI 3.85 · Net charge at pH 7.4: −1.06

Point or use arrow keys

Net charge of Linaclotide from pH 0 to 14 (EMBOSS pKa set). Isoelectric point 3.85. Net charge at pH 7.4: -1.06.−4−3−2−10+102468101214pHNet chargepH 7.4pI 3.85

Henderson-Hasselbalch, EMBOSS pKa set, 3 disulfide. Calculated, not measured.

Show as table
pHNet charge
01.00
11.00
20.97
30.73
4−0.16
5−0.85
6−0.99
7−1.02
8−1.22
9−1.86
10−2.85
11−3.77
12−3.97
13−4.00
14−4.00

Composition

  • Hydrophobic7% (1)
  • Aromatic14% (2)
  • Negative7% (1)
  • Polar14% (2)
  • Special57% (8)

14 residues. Each residue counts in one class; F and W count as aromatic.

A Ala1 · 7%
I Ile0 · 0%
L Leu0 · 0%
M Met0 · 0%
V Val0 · 0%
F Phe0 · 0%
W Trp0 · 0%
Y Tyr2 · 14%
H His0 · 0%
K Lys0 · 0%
R Arg0 · 0%
D Asp0 · 0%
E Glu1 · 7%
N Asn1 · 7%
Q Gln0 · 0%
S Ser0 · 0%
T Thr1 · 7%
C Cys6 · 43%
G Gly1 · 7%
P Pro1 · 7%

3D structure

No 3D structure

No experimental structure (PDB) and no UniProt entry for an AlphaFold model are listed for this peptide. Synthetic peptides often have neither. The sequence view above is the reference.

2D structure

Draws the structure in your browser with RDKit (about 2.3 MB, loaded once).

SMILES fromPubChem CID 16158208(opens in a new tab)

C[C@H]1C(=O)N[C@H]2CSSC[C@H]3C(=O)N[C@H](C(=O)N[C@H](C(=O)N[C@@H](CSSC[C@H](NC(=O)CNC(=O)[C@@H](NC2=O)[C@@H](C)O)C(=O)N[C@@H](CC4=CC=C(C=C4)O)C(=O)O)C(=O)N[C@@H](CSSC[C@@H](C(=O)N3)N)C(=O)N[C@H](C(=O)N5CCC[C@H]5C(=O)N1)CC(=O)N)CC6=CC=C(C=C6)O)CCC(=O)O

Helical wheel

An ideal alpha-helix projection. It shows where the hydrophobic residues fall if the peptide folds as a helix. It does not show that it does.

Helical wheel of Linaclotide, 14 residues at 100 degrees per residue. Hydrophobic moment 0.19 pointing at 56 degrees.Cys 1, Eisenberg consensus (normalized) 0.29C1Cys 2, Eisenberg consensus (normalized) 0.29C2Glu 3, Eisenberg consensus (normalized) -0.74E−3Tyr 4, Eisenberg consensus (normalized) 0.26Y4Cys 5, Eisenberg consensus (normalized) 0.29C5Cys 6, Eisenberg consensus (normalized) 0.29C6Asn 7, Eisenberg consensus (normalized) -0.78N7Pro 8, Eisenberg consensus (normalized) 0.12P8Ala 9, Eisenberg consensus (normalized) 0.62A9Cys 10, Eisenberg consensus (normalized) 0.29C10Thr 11, Eisenberg consensus (normalized) -0.05T11Gly 12, Eisenberg consensus (normalized) 0.48G12Cys 13, Eisenberg consensus (normalized) 0.29C13Tyr 14, Eisenberg consensus (normalized) 0.26Y14
μH, residues shown
0.191
μH, best 11-residue window
0.240
Arrow direction
56°
Residues
14
HydrophilicHydrophobic

Eisenberg consensus (normalized) scale · + K, R · − D, E

Assumes an ideal α-helix: 100° per residue, 3.6 residues per turn. The arrow is the mean hydrophobic moment (Eisenberg et al. 1984) and points at the hydrophobic face.

Show as table
PositionResidueAngleEisenberg consensus (normalized)
1C0°0.29
2C100°0.29
3E200°-0.74
4Y300°0.26
5C40°0.29
6C140°0.29
7N240°-0.78
8P340°0.12
9A80°0.62
10C180°0.29
11T280°-0.05
12G20°0.48
13C120°0.29
14Y220°0.26
Results by area

What the studies measured

People first in each area, then animals, then lab cells. Counts are exact and come from studies that gave the peptide.

Trials and papers
Status and safety
Data