Peptide name : Antimicrobial peptide TsAP-1

Source/Organism : Brazilian scorpion

Linear/Cyclic : Linear

Chirality : Not found

Peptide length: 73

C-terminal modification: Linear

N-terminal modification : Amidation

Non-natural peptide information: None

Assay type : MTT Cell viability assay

Assay time : 24h

Activity : IC50 : 0.83 - 2.0 μM

Cell line : U251

Cancer type : Human glioblastoma

Other activity : Hemolytic activity

Amino acid composition bar chart :

Molecular mass : 8409.8422 Dalton

Aliphatic index : 1.202

Instability index : 43.6466

Hydrophobicity (GRAVY) : 0.1301

Isoelectric point : 7.8948

Charge (pH 7) : 0.5908

Aromaticity : 0.082

Molar extinction coefficient (cysteine, cystine): (2980, 2980)

Hydrophobic/hydrophilic ratio : 1.14705882

hydrophobic moment : -0.236

Missing amino acid : N,W

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, 0.1, 0.4)

SMILES Notation: CC[C@H](C)[C@H](NC(=O)[C@H](CO)NC(=O)CNC(=O)CNC(=O)[C@@H](NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CO)NC(=O)[C@@H]1CCCN1C(=O)[C@@H](NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CO)NC(=O)[C@H](CC(C)C)NC(=O)[C@H](Cc1ccccc1)NC(=O)[C@H](C)NC(=O)[C@H](CO)NC(=O)[C@H](CS)NC(=O)[C@H](CCC(N)=O)NC(=O)[C@H](CC(=O)O)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](CC(C)C)NC(=O)[C@H](Cc1ccccc1)NC(=O)[C@H](Cc1ccccc1)NC(=O)[C@H](CC(C)C)NC(=O)[C@@H](NC(=O)[C@@H](NC(=O)[C@H](CC(C)C)NC(=O)[C@H](Cc1c[nH]cn1)NC(=O)[C@H](CCCCN)NC(=O)[C@@H](NC(=O)[C@H](CCC(N)=O)NC(=O)[C@@H](N)CCSC)[C@@H](C)CC)[C@@H](C)CC)[C@@H](C)O)C(C)C)[C@@H](C)CC)C(C)C)[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)NCC(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CCC(=O)O)C(=O)N[C@H](C(=O)N[C@@H](CO)C(=O)N[C@@H](C)C(=O)N[C@@H](CCC(N)=O)C(=O)N[C@H](C(=O)N[C@@H](CCC(=O)O)C(=O)N[C@@H](CCC(N)=O)C(=O)N[C@@H](Cc1ccc(O)cc1)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CC(=O)O)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CCC(N)=O)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CCC(=O)O)C(=O)N[C@@H](C)C(=O)N[C@@H](CCC(=O)O)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CCC(=O)O)C(=O)N[C@@H](CCC(=O)O)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CC(=O)O)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CC(C)C)C(=O)N1CCC[C@H]1C(=O)N[C@@H](CCSC)C(=O)N[C@@H](Cc1ccc(O)cc1)C(=O)O)[C@@H](C)CC)[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

2 : Echeverría-Rodríguez O, et al. Angiotensin 1-7 improves insulin sensitivity by increasing skeletal muscle glucose uptake in vivo. Peptides. 2014; 51:26-30. doi: 10.1016/j.peptides.2013.10.022

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.

Paper title : Angiotensin 1-7 improves insulin sensitivity by increasing skeletal muscle glucose uptake in vivo.

Doi : https://doi.org/10.1016/j.peptides.2013.10.022

Abstract : The renin-angiotensin system (RAS) regulates skeletal muscle insulin sensitivity through different mechanisms. The overactivation of the ACE (angiotensin-converting enzyme)/Ang (angiotensin) II/AT1R (Ang II type 1 receptor) axis has been associated with the development of insulin resistance, whereas the stimulation of the ACE2/Ang 1-7/MasR (Mas receptor) axis improves insulin sensitivity. The in vivo mechanisms by which this axis enhances skeletal muscle insulin sensitivity are scarcely known. In this work, we investigated whether rat soleus muscle expresses the ACE2/Ang 1-7/MasR axis and determined the effect of Ang 1-7 on rat skeletal muscle glucose uptake in vivo. Western blot analysis revealed the expression of ACE2 and MasR, while Ang 1-7 levels were detected in rat soleus muscle by capillary zone electrophoresis. The euglycemic clamp exhibited that Ang 1-7 by itself did not promote glucose transport, but it increased insulin-stimulated glucose disposal in the rat. In a similar manner, captopril (an ACE inhibitor) enhanced insulin-induced glucose uptake and this effect was blocked by the MasR antagonist A-779. Our results show for the first time that rat soleus muscle expresses the ACE2/Ang 1-7/MasR axis of the RAS, and Ang 1-7 improves insulin sensitivity by enhancing insulin-stimulated glucose uptake in rat skeletal muscle in vivo. Thus, endogenous (systemic and/or local) Ang 1-7 could regulate insulin-mediated glucose transport in vivo.