Peptide name : TsAP-2

Source/Organism : Venom, the Brazilian yellow scorpion, South America

Linear/Cyclic : Linear

Chirality : L

Peptide length: 17

C-terminal modification: Linear

N-terminal modification : Amidation

Non-natural peptide information: None

Assay type : MTT/MTS assay

Assay time : 24h

Activity : IC50 : 15.4 µM

Cell line : U251-MG

Cancer type : Human squamous carcinoma

Other activity : Hemolytic activity

Amino acid composition bar chart :

Molecular mass : 1734.1524 Dalton

Aliphatic index : 1.435

Instability index : 6.1353

Hydrophobicity (GRAVY) : 1.5471

Isoelectric point : 8.7501

Charge (pH 7) : 0.7591

Aromaticity : 0.117

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

Hydrophobic/hydrophilic ratio : 7.5

hydrophobic moment : 1.2588

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

Most occurring amino acid : G

Most occurring amino acid frequency : 4

Least occurring amino acid : M

Least occurring amino acid frequency : 1

Secondary structure fraction (Helix, Turn, Sheet): (0.3, 0.3, 0.4)

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

1 : Guo X, et al. Two peptides, TsAP-1 and TsAP-2, from the venom of the Brazilian yellow scorpion, Tityus serrulatus: evaluation of their antimicrobial and anticancer activities. Biochimie. 2013; 95:1784-94. doi: 10.1016/j.biochi.2013.06.003

Paper title : Two peptides, TsAP-1 and TsAP-2, from the venom of the Brazilian yellow scorpion, Tityus serrulatus: evaluation of their antimicrobial and anticancer activities.

Doi : https://doi.org/10.1016/j.biochi.2013.06.003

Abstract : Here we report two novel 17-mer amidated linear peptides (TsAP-1 and TsAP-2) whose structures were deduced from cDNAs cloned from a venom-derived cDNA library of the Brazilian yellow scorpion, Tityus serrulatus. Both mature peptides were structurally-characterised following their location in chromatographic fractions of venom and synthetic replicates of each were subjected to a range of biological assays. The peptides were each active against model test micro-organisms but with different potencies. TsAP-1 was of low potency against all three test organisms (MICs 120-160 μM), whereas TsAP-2 was of high potency against the Gram-positive bacterium, Staphylococcus aureus (MIC 5 μM) and the yeast, Candida albicans (10 μM). Haemolytic activity of TsAP-1 was low (4% at 160 μM) and in contrast, that of TsAP-2 was considerably higher (18% at 20 μM). Substitution of four neutral amino acid residues with Lys residues in each peptide had dramatic effects on their antimicrobial potencies and haemolytic activities, particularly those of TsAP-1. The MICs of the enhanced cationic analogue (TsAP-S1) were 2.5 μM for S. aureus/C. albicans and 5 μM for E. coli but with an associated large increase in haemolytic activity (30% at 5 μM). The same Lys residue substitutions in TsAP-2 produced a dramatic effect on its MIC for E. coli lowering this from >320 μM to 5 μM. TsAP-1 was ineffective against three of the five human cancer cell lines tested while TsAP-2 inhibited the growth of all five. Lys residue substitution of both peptides enhanced their potency against all five cell lines with TsAp-S2 being the most potent with IC50 values ranging between 0.83 and 2.0 μM. TsAP-1 and TsAP-2 are novel scorpion venom peptides with broad spectrum antimicrobial and anticancer cell activities the potencies of which can be significantly enhanced by increasing their cationicity.