ProForma 2.0
validated simple linear
YVRHLKYVRHLK
Back to Primary literature
Primary-literature peptidemedium evidence PepDiana evidence grade for a literature-derived identity; Medium indicates retained review flags, while High has no unresolved review flag.
PEPDIA-PLP-003361
P21
Aliases: P21
Normalized sequence
YVRHLKYVRHLK
12 amino acids
Release PepDiana-V1-20260620
4
Activity records
1
Source papers
3
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
1611.9335 Da
Molecular formula
C76H122N24O15
Theoretical pI
10.4468
Net charge at pH 7
3.9304
GRAVY
-0.8167
Instability index
27.1167
Aromaticity
0.1667
Topological polar surface area
657.08 Ų
cLogP
-2.252
Hydrogen-bond donors
25
Hydrogen-bond acceptors
21
Rotatable bonds
53
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{Y.V.R.H.L.K.Y.V.R.H.L.K}$$$$V2.0
Canonical SMILES
validated
CC(C)CC(NC(=O)C(Cc1c[nH]cn1)NC(=O)C(CCCNC(=N)N)NC(=O)C(NC(=O)C(Cc1ccc(O)cc1)NC(=O)C(CCCCN)NC(=O)C(CC(C)C)NC(=O)C(Cc1c[nH]cn1)NC(=O)C(CCCNC(=N)N)NC(=O)C(NC(=O)C(N)Cc1ccc(O)cc1)C(C)C)C(C)C)C(=O)NC(CCCCN)C(=O)O
Isomeric SMILES
validated
CC(C)C[C@H](NC(=O)[C@H](Cc1c[nH]cn1)NC(=O)[C@H](CCCNC(=N)N)NC(=O)[C@@H](NC(=O)[C@H](Cc1ccc(O)cc1)NC(=O)[C@H](CCCCN)NC(=O)[C@H](CC(C)C)NC(=O)[C@H](Cc1c[nH]cn1)NC(=O)[C@H](CCCNC(=N)N)NC(=O)[C@@H](NC(=O)[C@@H](N)Cc1ccc(O)cc1)C(C)C)C(C)C)C(=O)N[C@@H](CCCCN)C(=O)O
Paper-level observations
Experimental evidence grouped by activity
Toxicity 2 records
PMC10126514
2 observationsToxicityCytotoxicNegative / threshold
Record detail Figure 3D: the cell viability of P21 was significantly reduced at 25 uM (p < 0.05), and the cytotoxic peptide concentration produced at this time was higher than that of other peptides, and the cytotoxicity of P21 itself was lower.
- Measure
- cell_viability
- Value
- cell viability significantly reduced at 25 uM (p<0.05)
- Target
- Rattus norvegicus
- Assay
- Not reported by source
ToxicityCytotoxicPositive observation
Record detail Figure 5: P21 polypeptide has a good inhibitory effect on the PC12 cytotoxicity caused by the aggregation of Aβ1-42 at a low concentration ratio (1:0.25 and 1:0.5). After the concentration ratio of P21 reached 1:1, with the increase of P21 concentration (1:2, 1:4), cell viability continued to increase, reaching the maximum at 1:4, which was close to the normal level.
- Measure
- cell_viability
- Value
- cell viability increased with P21 concentration, reaching maximum at 1:4 ratio, close to normal level
- Target
- Rattus norvegicus
- Assay
- Not reported by source
Other 2 records
PMC10126514
2 observationsOtherAnti-AggregationPositive observation
Record detail Figure 4: P21 makes the fluorescence intensity of Aβ1-42 aggregation significantly lower than that of the Aβ group (p < 0.05), which can achieve 100% inhibition.
- Measure
- percent_inhibition
- Value
- 100% inhibition (p<0.05)
- Target
- Aβ1-42
- Assay
- Not reported by source
OtherBinding AffinityPositive observation
Record detail Table 3: KD (M) for P21 is 5.385 × 10−5.
- Measure
- Kd
- Value
- 5.385 × 10−5 M
- Target
- Aβ1-42
- Assay
- Not reported by source
Citation and release provenance
Cite this identity as PepDiana record PEPDIA-PLP-003361, release PepDiana-V1-20260620. Experimental observations retain their paper, mention, and activity-record identifiers.
Record updated: 2026-06-22T07:14:26.229247+00:00