ProForma 2.0
validated simple linear
FPITVGIVMPKKFIKKLRKK
Back to Primary literature
Primary-literature peptidehigh evidence PepDiana evidence grade for a literature-derived identity; Medium indicates retained review flags, while High has no unresolved review flag.
PEPDIA-PLP-000777
P4
Aliases: Ctn_15_34_retro, Ctn_15_34_retroenantio, P4
Normalized sequence
FPITVGIVMPKKFIKKLRKK
20 amino acids
Release PepDiana-V1-20260620
14
Activity records
2
Source papers
13
Positive
1
Negative / threshold
Versioned scientific descriptors
Physicochemical properties and standard representations
Reported properties
No separate physicochemical property was reported in the primary-literature identity record. PepDiana release values are shown as computed properties.
Computed properties
physchem-20260620Molecular weight
2372.0564 Da
Molecular formula
C115H199N29O22S
Theoretical pI
11.4335
Net charge at pH 7
6.7541
GRAVY
0.05
Instability index
29.505
Aromaticity
0.1
Topological polar surface area
836.89 Ų
cLogP
-1.5937
Hydrogen-bond donors
29
Hydrogen-bond acceptors
30
Rotatable bonds
83
Method: PepDiana sequence/structure descriptor pipeline
Tool: Biopython+RDKit · Biopython 1.85; RDKit 2024.09.6
Calculated: 2026-06-20T11:01:38.358971+00:00
Assumptions: ph=7; termini=free N-terminus and free C-terminus for simple linear peptides; stereochemistry=standard L-amino acids; smiles_length_limit=200
Sequence representations
HELM 2.0
validated simple linear
PEPTIDE1{F.P.I.T.V.G.I.V.M.P.K.K.F.I.K.K.L.R.K.K}$$$$V2.0
Canonical SMILES
validated
CCC(C)C(NC(=O)CNC(=O)C(NC(=O)C(NC(=O)C(NC(=O)C1CCCN1C(=O)C(N)Cc1ccccc1)C(C)CC)C(C)O)C(C)C)C(=O)NC(C(=O)NC(CCSC)C(=O)N1CCCC1C(=O)NC(CCCCN)C(=O)NC(CCCCN)C(=O)NC(Cc1ccccc1)C(=O)NC(C(=O)NC(CCCCN)C(=O)NC(CCCCN)C(=O)NC(CC(C)C)C(=O)NC(CCCNC(=N)N)C(=O)NC(CCCCN)C(=O)NC(CCCCN)C(=O)O)C(C)CC)C(C)C
Isomeric SMILES
validated
CC[C@H](C)[C@H](NC(=O)CNC(=O)[C@@H](NC(=O)[C@@H](NC(=O)[C@@H](NC(=O)[C@@H]1CCCN1C(=O)[C@@H](N)Cc1ccccc1)[C@@H](C)CC)[C@@H](C)O)C(C)C)C(=O)N[C@H](C(=O)N[C@@H](CCSC)C(=O)N1CCC[C@H]1C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](Cc1ccccc1)C(=O)N[C@H](C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCCCN)C(=O)O)[C@@H](C)CC)C(C)C
Paper-level observations
Experimental evidence grouped by activity
Antimicrobial 7 records
PMC9495681
6 observationsAntimicrobialAnti-Gram-Positive observation
Record detail Table 2: Ctn[15-34] retro MIC against E. coli 0.16 μM
- Measure
- MIC
- Value
- 0.16 µM
- Target
- Escherichia coli
- Assay
- Not reported by source
AntimicrobialAnti-Gram-Positive observation
Record detail Table 2: Ctn[15-34] retro MIC against A. baumannii 0.78 μM
- Measure
- MIC
- Value
- 0.78 µM
- Target
- Acinetobacter baumannii
- Assay
- Not reported by source
AntimicrobialAnti-Gram-Positive observation
Record detail Table 2: Ctn[15-34] retro MIC against Pseudomonas sp. <0.05 μM
- Measure
- MIC
- Value
- <0.05 µM
- Target
- Pseudomonas sp.
- Assay
- Not reported by source
AntimicrobialAnti-Gram-Positive observation
Record detail Table 2: Ctn[15-34] retroenantio MIC against E. coli 0.16 μM
- Measure
- MIC
- Value
- 0.16 µM
- Target
- Escherichia coli
- Assay
- Not reported by source
AntimicrobialAnti-Gram-Positive observation
Record detail Table 2: Ctn[15-34] retroenantio MIC against A. baumannii 0.39 μM
- Measure
- MIC
- Value
- 0.39 µM
- Target
- Acinetobacter baumannii
- Assay
- Not reported by source
AntimicrobialAnti-Gram-Positive observation
Record detail Table 2: Ctn[15-34] retroenantio MIC against Pseudomonas sp. 0.1 μM
- Measure
- MIC
- Value
- 0.1 µM
- Target
- Pseudomonas sp.
- Assay
- Not reported by source
PMC11431785
1 observationsAntimicrobialAntibacterialPositive observation
Record detail Table 1: Ctn[15-34] re MIC (μM) A. baumannii = 0.39
- Measure
- MIC
- Value
- 0.39 μM
- Target
- Acinetobacter baumannii
- Assay
- Not reported by source
Toxicity 2 records
PMC11431785
2 observationsToxicityCytotoxicPositive observation
Record detail Table 1: Ctn[15-34] re IC50 (μM) = 43. Methods Section 3.4 describes cytotoxicity assay on 1BR3G human fibroblast cells.
- Measure
- other
- Value
- 43 μM
- Target
- 1BR3G
- Assay
- Not reported by source
ToxicityGeneral ToxicNegative / threshold
Record detail Section 2.2: 'Ctn[15-34] re ... an animal died within 3 min at 30 mg/kg, within 6 min at 15 mg/kg, and after 33 min at 5 mg/kg.' Sighting study.
- Measure
- MTD
- Value
- toxic: death within 3 min at 30 mg/kg, 6 min at 15 mg/kg, 33 min at 5 mg/kg
- Target
- Mus musculus
- Assay
- Not reported by source
Other 2 records
PMC11431785
1 observationsOtherPositive observation
Record detail Table 1: Ctn[15-34] re t1/2 (min) = 921 (serum stability).
- Measure
- other
- Value
- 921 other
- Target
- Not reported by source
- Assay
- Not reported by source
PMC9495681
1 observationsOtherPositive observation
Record detail Section 3.5: Ctn[15-34] retroenantio, with unusually high serum stability (t1/2 = 921 min)
- Measure
- other
- Value
- t1/2 = 921 min
- Target
- Homo sapiens
- Assay
- Not reported by source
Anticancer 2 records
PMC9495681
2 observationsAnticancerCytotoxicPositive observation
Record detail Section 3.3: neither Ctn[15-34] (IC50 ≈ 14.32 μM) nor its retro version (IC50 ≈ 15.84 μM) were toxic
- Measure
- other
- Value
- ≈ 15.84 µM
- Target
- 1BR3G
- Assay
- Not reported by source
AnticancerCytotoxicPositive observation
Record detail Section 3.3: versus 191 μM and 43 μM for Ctn[15-34] enantio and Ctn[15-34] retroenantio
- Measure
- other
- Value
- 43 µM
- Target
- 1BR3G
- Assay
- Not reported by source
Immunomodulatory 1 records
PMC11431785
1 observationsImmunomodulatoryPositive observation
Record detail Section 2.4: 'For Ctn[15-34] re ... at LPS/peptide ratios of 0.1:0.1, TNF-α levels evidencing high inflammation ... were found.'
- Measure
- other
- Value
- high inflammation at LPS/peptide 0.1:0.1
- Target
- human MNC
- Assay
- Not reported by source
Citation and release provenance
Cite this identity as PepDiana record PEPDIA-PLP-000777, release PepDiana-V1-20260620. Experimental observations retain their paper, mention, and activity-record identifiers.
Record updated: 2026-06-22T07:14:26.229247+00:00