Peptide name : StigA6

Source/Organism : Amino acid substitution, animal-derived, natural derivative

Linear/Cyclic : Not found

Chirality : Not found

Peptide length: 17

C-terminal modification: Not found

N-terminal modification : Amidation

Non-natural peptide information: None

Assay type : MTT assay

Assay time : 24h

Activity : IC 50 : 14.01 μM

Cell line : HeLa

Cancer type : Mouse melanoma

Other activity : Anti-bacterial activity

Amino acid composition bar chart :

Molecular mass : 1908.3716 Dalton

Aliphatic index : 1.376

Instability index : -12.805

Hydrophobicity (GRAVY) : 1.1471

Isoelectric point : 10.302

Charge (pH 7) : 2.7571

Aromaticity : 0.176

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

Hydrophobic/hydrophilic ratio : 2.4

hydrophobic moment : 1.6527

Missing amino acid : C,R,W,H,Q,T,M,E,D,Y,N

Most occurring amino acid : F

Most occurring amino acid frequency : 3

Least occurring amino acid : P

Least occurring amino acid frequency : 1

Secondary structure fraction (Helix, Turn, Sheet): (0.4, 0.2, 0.5)

SMILES Notation: CC[C@H](C)[C@H](NC(=O)[C@H](CC(C)C)NC(=O)CNC(=O)[C@H](CCCCN)NC(=O)[C@@H](NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CCCCN)NC(=O)[C@@H]1CCCN1C(=O)[C@@H](NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CO)NC(=O)[C@H](Cc1ccccc1)NC(=O)[C@@H](N)Cc1ccccc1)[C@@H](C)CC)C(C)C)C(=O)N[C@@H](CO)C(=O)N[C@@H](C)C(=O)N[C@@H](Cc1ccccc1)C(=O)N[C@@H](CCCCN)C(=O)O

1 : Parente AMS, et al. Analogs of the Scorpion Venom Peptide Stigmurin: Structural Assessment, Toxicity, and Increased Antimicrobial Activity. Toxins (Basel). 2018; 10:(unknown pages). doi: 10.3390/toxins10040161

Paper title : Analogs of the Scorpion Venom Peptide Stigmurin: Structural Assessment, Toxicity, and Increased Antimicrobial Activity.

Doi : https://doi.org/10.3390/toxins10040161

Abstract : Scorpion venom is a rich source of biologically active components and various peptides with high-potential therapeutic use that have been characterized for their antimicrobial and antiproliferative activities. Stigmurin is a peptide identified from the Tityus stigmurus venom gland with high antibacterial and antiproliferative activities and low toxicity. Amino acid substitutions in peptides without a disulfide bridge sequence have been made with the aim of reducing their toxicity and increasing their biological activities. The purpose of this study was to evaluate the structural conformation and structural stability, as well as antimicrobial, antiproliferative, and hemolytic activities of two peptide analogs to Stigmurin, denominated StigA6 and StigA16. In silico analysis revealed the α-helix structure for both analog peptides, which was confirmed by circular dichroism. Data showed that the net charge and hydrophobic moment of the analog peptides were higher than those for Stigmurin, which can explain the increase in antimicrobial activity presented by them. Both analog peptides exhibited activity on cancerous cells similar to the native peptide; however, they were less toxic when tested on the normal cell line. These results reveal a potential biotechnological application of the analog peptides StigA6 and StigA16 as prototypes to new therapeutic agents.