Peptide name : PS9

Source/Organism : Aphanomyces invadans

Linear/Cyclic : Linear

Chirality : L

Peptide length: 9

C-terminal modification: Linear

N-terminal modification : Free

Non-natural peptide information:

Assay type : Neutral Red Uptake assay

Assay time : 24-h

Activity : IC50 value range between 25.27 - 43.28 μM

Cell line : MCF-7

Cancer type : Breast Cancer

Other activity : Anticancer

Amino acid composition bar chart :

Molecular mass : 1103.3376 Dalton

Aliphatic index : 0.755

Instability index : 68.5667

Hydrophobicity (GRAVY) : -0.288

Isoelectric point : 11.005

Charge (pH 7) : 1.9575

Aromaticity : 11.11

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

Hydrophobic/hydrophilic ratio : 1.25

hydrophobic moment : -0.033

Missing amino acid : A,C,D,E,F,G,H,I,N,Q,T,Y

Most occurring amino acid : S

Most occurring amino acid frequency : 2

Least occurring amino acid : P

Least occurring amino acid frequency : 1

Secondary structure fraction (Helix, Turn, Sheet): (33., 33., 33.)

SMILES Notation: CSCC[C@H](NC(=O)[C@@H](NC(=O)[C@H](CCCCN)NC(=O)[C@H](CCCNC(=N)N)NC(=O)[C@H](CO)NC(=O)[C@@H]1CCCN1)C(C)C)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](Cc1c[nH]c2ccccc12)C(=O)N[C@@H](CO)C(=O)O

1 : Velayutham M, et al. PS9, Derived from an Aquatic Fungus Virulent Protein, Glycosyl Hydrolase, Arrests MCF-7 Proliferation by Regulating Intracellular Reactive Oxygen Species and Apoptotic Pathways. ACS Omega. 2023; 8:18543-18553. doi: 10.1021/acsomega.3c00336

Paper title : PS9, Derived from an Aquatic Fungus Virulent Protein, Glycosyl Hydrolase, Arrests MCF-7 Proliferation by Regulating Intracellular Reactive Oxygen Species and Apoptotic Pathways.

Doi : https://doi.org/10.1021/acsomega.3c00336

Abstract : One of the most common diseases in women is breast cancer, which has the highest death globally. Surgery, chemotherapy, hormone treatments, and radiation are the current treatment options for breast cancer. However, these options have several adverse side effects. Recently, peptide-based drugs have gained attention as anticancer therapy. Studies report that peptides from biological toxins such as venom and virulent pathogenic molecules have potential therapeutic effects against multiple diseases, including cancers. This study reports on the in vitro anticancer effect of a short peptide, PS9, derived from a virulent protein, glycosyl hydrolase, of an aquatic fungus, Aphanomyces invadans. This peptide arrests MCF-7 proliferation by regulating intercellular reactive oxygen species (ROS) and apoptotic pathways. Based on the potential for the anticancer effect of PS9, from the in silico analysis, in vitro analyses using MCF-7 cells were executed. PS9 showed a dose-dependent activity; its IC₅₀ value was 25.27-43.28 μM at 24 h. The acridine orange/ethidium bromide (AO/EtBr) staining, to establish the status of apoptosis in MCF-7 cells, showed morphologies for early and late apoptosis and necrotic cell death. The 2,7-dichlorodihydrofluorescein diacetate (DCFDA) staining and biochemical analyses showed a significant increase in reactive oxygen species (ROS). Besides, PS9 has been shown to regulate the caspase-mediated apoptotic pathway. PS9 is nontoxic, in vitro, and in vivo zebrafish larvae. Together, PS9 may have an anticancer effect in vitro.