Peptide name : Pantinin-3

Source/Organism : Synthetic

Linear/Cyclic : Linear

Chirality : L

Peptide length: 13

C-terminal modification: Linear

N-terminal modification : Free

Non-natural peptide information:

Assay type : MTS assay

Assay time : 24-h

Activity : IC50 = 13.5 ± 2.0 µM

Cell line : MDA-MB-231

Cancer type : Breast Cancer

Other activity : Antimicrobial

Amino acid composition bar chart :

Molecular mass : 1491.7717 Dalton

Aliphatic index : 1.5

Instability index : -5.9

Hydrophobicity (GRAVY) : 0.9385

Isoelectric point : 8.7501

Charge (pH 7) : 0.7591

Aromaticity : 15.38

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

Hydrophobic/hydrophilic ratio : 1.6

hydrophobic moment : 1.0974

Missing amino acid : A,C,D,E,H,M,P,Q,R,V,Y

Most occurring amino acid : L

Most occurring amino acid frequency : 3

Least occurring amino acid : F

Least occurring amino acid frequency : 1

Secondary structure fraction (Helix, Turn, Sheet): (30., 30., 61.)

SMILES Notation: CC[C@H](C)[C@H](NC(=O)CNC(=O)[C@H](CC(N)=O)NC(=O)[C@H](Cc1c[nH]c2ccccc12)NC(=O)[C@@H](NC(=O)[C@@H](NC(=O)[C@H](CO)NC(=O)[C@H](CC(C)C)NC(=O)[C@@H](N)Cc1ccccc1)[C@@H](C)O)[C@@H](C)CC)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CO)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CC(C)C)C(=O)O

1 : Crusca E, et al. Biophysical characterization and antitumor activity of synthetic Pantinin peptides from scorpion's venom. Biochim Biophys Acta Biomembr. 2018; 1860:2155-2165. doi: 10.1016/j.bbamem.2018.08.012

Paper title : Biophysical characterization and antitumor activity of synthetic Pantinin peptides from scorpion's venom.

Doi : https://doi.org/10.1016/j.bbamem.2018.08.012

Abstract : Antimicrobial peptides have been extensively described as bioactive agents, mainly considering their selective toxicity towards bacteria but not to healthy mammalian cells. In past years, this class of compounds has been classified as an attractive and novel family of anticancer agents. Pantinin peptides isolated from scorpion Pandinus imperator presented antimicrobial activity. In this study, we have explored the in vitro antitumor activity of antimicrobial pantinin peptides against the tumor cell lines MDA-MB-231 (breast adenocarcinoma) and DU - 145 (prostate adenocarcinoma) and healthy fibroblasts HGF - 1. To further improve our mechanistic understanding for this class of compounds, we have also performed a biophysical characterization of these peptides in lipid model membranes. Cell viability assays revealed that all peptides were more effective on tumor cells when compared to fibroblasts, indicating selectivity towards cancer cells. Furthermore, flow cytometry analysis revealed that all peptides induced apoptosis in cancer cells in a different way from fibroblasts. Circular dichroism spectroscopy showed that all peptides adopted an α-helical structure and an evaluation of the binding constant indicates a higher affinity of the peptides to negatively charged phospholipids. Additionally, permeabilization assays showed that POPG and POPS anionic vesicles were more susceptible to peptide-induced lysis than POPC:Chol and POPC:POPE vesicles. Moreover, we have observed that increasing concentrations of cholesterol inhibits peptide binding process. Therefore, our findings suggest that Pantinin peptides may have chemotherapeutic potential for cancer treatment.