Peptide name : Sepia ink oligopeptide (SIO)

Source/Organism : Not found

Linear/Cyclic : Linear

Chirality : L

Peptide length: 3

C-terminal modification: Linear

N-terminal modification : Not found

Non-natural peptide information: None

Assay type : CCK-8 assay

Assay time : 24h

Activity : IC50 : < 5 mg/mL

Cell line : DU-145

Cancer type : Prostate cancer

Other activity : Not found

Amino acid composition bar chart :

Molecular mass : 371.432 Dalton

Aliphatic index : 0

Instability index : 70.8667

Hydrophobicity (GRAVY) : -3

Isoelectric point : 8.7501

Charge (pH 7) : 0.7591

Aromaticity : 0

Molar extinction coefficient (cysteine, cystine): (0, 0)

Hydrophobic/hydrophilic ratio : 0.5

hydrophobic moment : 0.1475

Missing amino acid : W,T,I,M,E,F,D,N,G,C,R,H,S,Y,L,A,V

Most occurring amino acid : Q

Most occurring amino acid frequency : 1

Least occurring amino acid : Q

Least occurring amino acid frequency : 1

Secondary structure fraction (Helix, Turn, Sheet): (0.3, 0.3, 0)

SMILES Notation: NCCCC[C@H](NC(=O)[C@@H]1CCCN1C(=O)[C@@H](N)CCC(N)=O)C(=O)O

1 : Huang F, et al. Sepia ink oligopeptide induces apoptosis in prostate cancer cell lines via caspase-3 activation and elevation of Bax/Bcl-2 ratio. Mar Drugs. 2012; 10:2153-2165. doi: 10.3390/md10102153

Paper title : Sepia ink oligopeptide induces apoptosis in prostate cancer cell lines via caspase-3 activation and elevation of Bax/Bcl-2 ratio.

Doi : https://doi.org/10.3390/md10102153

Abstract : Sepia ink oligopeptide (SIO) is a tripeptide extracted from Sepia ink. To test the hypothesis that SIO inhibits prostate cancer by inducing apoptosis, the effects of SIO on the proliferation of three human prostate cancer cell lines were examined using a CCK-8 assay. SIO significantly inhibited the proliferation of DU-145, PC-3 and LNCaP cells in a time- and dose-dependent manner. Flow cytometry studies showed that exposing DU-145, PC-3 and LNCaP cells to 5, 10, or 15 mg/mL SIO for 24 h increased the percentage of the early-stage apoptotic cells from 11.84% to 38.26% (DU-145), 22.76% to 39.96% (PC-3) and 5.05% to 16.11% (LNCaP), respectively. In addition, typical morphologic changes were observed in the cells with acridine orange/ethidium bromide staining. SIO treatment induced strong S and G₂/M phase cell cycle arrest in a dose-dependent manner in DU-145 and LNCaP. In contrast, SIO treatment induced strong Sub G₁ and G₀/G₁ phase cell cycle arrest in a dose-dependent manner in PC-3. SIO exposure for 24 h decreased the expression of the anti-apoptotic protein Bcl-2 and increased the expression of the apoptogenic protein Bax. Moreover, the Bax/Bcl-2expression ratio was increased. Concurrently, the expression of caspase-3 was upregulated. These data support our hypothesis that SIO has anticarcinogenic properties.