Peptide name : Amphipathic peptide CT1

Source/Organism : Scorpions, Morelos, located in South-Central Mexico (Mexican scorpion)

Linear/Cyclic : linear

Chirality : Not found

Peptide length: 68

C-terminal modification: linear

N-terminal modification : Free

Non-natural peptide information: None

Assay type : MTT/MTS assay

Assay time : 24h

Activity : IC50 : 6.3-12.5 μM

Cell line : MCF-7

Cancer type : Breast cancer

Other activity : Anti-microbial activity

Amino acid composition bar chart :

Molecular mass : 7769.9438 Dalton

Aliphatic index : 1.189

Instability index : 49.6912

Hydrophobicity (GRAVY) : 0.2456

Isoelectric point : 4.832

Charge (pH 7) : -3.3995

Aromaticity : 0.102

Molar extinction coefficient (cysteine, cystine): (6990, 6990)

Hydrophobic/hydrophilic ratio : 1.26666666

hydrophobic moment : 0.0293

Missing amino acid : C

Most occurring amino acid : L

Most occurring amino acid frequency : 12

Least occurring amino acid : H

Least occurring amino acid frequency : 1

Secondary structure fraction (Helix, Turn, Sheet): (0.4, 0.2, 0.4)

SMILES Notation: CC[C@H](C)[C@H](NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CCC(N)=O)NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CC(C)C)NC(=O)[C@@H](NC(=O)[C@@H](NC(=O)[C@H](C)NC(=O)[C@@H](NC(=O)[C@@H](NC(=O)[C@H](CC(C)C)NC(=O)[C@@H](NC(=O)[C@@H](NC(=O)[C@H](Cc1ccccc1)NC(=O)[C@H](CCC(N)=O)NC(=O)[C@@H](NC(=O)[C@H](CCCCN)NC(=O)[C@@H](N)CCSC)[C@@H](C)O)C(C)C)[C@@H](C)CC)[C@@H](C)CC)C(C)C)C(C)C)C(C)C)C(=O)N[C@@H](CO)C(=O)N[C@@H](Cc1c[nH]cn1)C(=O)N[C@@H](CO)C(=O)N[C@@H](CCC(=O)O)C(=O)N[C@@H](C)C(=O)N[C@@H](Cc1ccccc1)C(=O)N[C@@H](CC(C)C)C(=O)NCC(=O)N[C@@H](C)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](Cc1c[nH]c2ccccc12)C(=O)N[C@@H](CC(N)=O)C(=O)N[C@H](C(=O)N[C@@H](C)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CO)C(=O)N[C@H](C(=O)N[C@@H](Cc1ccccc1)C(=O)NCC(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCCNC(=N)N)C(=O)NCC(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CC(N)=O)C(=O)N[C@@H](Cc1ccccc1)C(=O)N[C@@H](CC(=O)O)C(=O)N[C@@H](CC(=O)O)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CC(=O)O)C(=O)N[C@@H](CC(=O)O)C(=O)N[C@H](C(=O)N[C@@H](Cc1ccccc1)C(=O)N[C@@H](CCC(=O)O)C(=O)N1CCC[C@H]1C(=O)N[C@@H](CCC(=O)O)C(=O)N[C@@H](CCSC)C(=O)N[C@@H](CO)C(=O)N[C@@H](CCC(=O)O)C(=O)N[C@@H](C)C(=O)N[C@@H](CC(=O)O)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](Cc1ccc(O)cc1)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CCC(N)=O)C(=O)N[C@@H](CC(=O)O)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CCCNC(=N)N)C(=O)O)[C@@H](C)O)C(C)C)C(C)C

1 : Pedron CN, et al. The effect of lysine substitutions in the biological activities of the scorpion venom peptide VmCT1. Eur J Pharm Sci. 2019; 136:104952. doi: 10.1016/j.ejps.2019.06.006

Paper title : The effect of lysine substitutions in the biological activities of the scorpion venom peptide VmCT1.

Doi : https://doi.org/10.1016/j.ejps.2019.06.006

Abstract : Antimicrobial peptides (AMPs) are biologically active molecules with a broad-spectrum activity against a myriad of microorganisms. Aside from their antimicrobial functions, AMPs present physicochemical and structural properties that allow them to exert activity against other kind of cells, such as cancer cells. VmCT1 is a potent cationic amphipathic AMP from the venom of the scorpion Vaejovis mexicanus. In this study, we designed lysine-substituted VmCT1 analogs for verifying the influence of changes in the net positive charge on biological activities. The increase in the net positive charge caused by lysine substitutions in the hydrophilic portion, led to higher antimicrobial activity values (0.1-6.3 μmol L-1) than VmCT1 (0.8-50 μmol L-1) and higher activity against mammary cancer cells MCF-7 (6.3-12.5 μmol L-1) than VmCT1 (12.5 μmol L-1). Contrarily, when lysine-substitutions were made at the hydrophobic portion of the helical projection, the activity values decreased. However, the lysine-substitution at the center of the hydrophobic face led to the generation of an analog with antiplasmodial activity at the same concentration presented by VmCT1 (0.8 μmol L-1). In this study, we demonstrated that it is possible to modulate biological activities and cytotoxicity of VmCT1 peptides by increasing their net positive charge using lysine residues, thus creating alternatives for standard-of-care therapeutics against different types of microorganisms and MCF-7 human breast cancer cells.