Peptide name : Latarcin 2a

Source/Organism : Central Asian spider

Linear/Cyclic : Linear

Chirality : L

Peptide length: 26

C-terminal modification: Linear

N-terminal modification : Free

Non-natural peptide information: None

Assay type : LDH leakage assay

Assay time : Not found

Activity : Not found

Cell line : Breast tumor cell line

Cancer type : Breast cancer

Other activity : Anti-microbial activity

Amino acid composition bar chart :

Molecular mass : 2902.5305 Dalton

Aliphatic index : 0.826

Instability index : 1.2885

Hydrophobicity (GRAVY) : -0.438

Isoelectric point : 11.333

Charge (pH 7) : 8.8393

Aromaticity : 0.115

Molar extinction coefficient (cysteine, cystine): (1490, 1490)

Hydrophobic/hydrophilic ratio : 1.16666666

hydrophobic moment : -0.527

Missing amino acid : C,W,Q,T,P,M,E,D,N

Most occurring amino acid : K

Most occurring amino acid frequency : 7

Least occurring amino acid : S

Least occurring amino acid frequency : 1

Secondary structure fraction (Helix, Turn, Sheet): (0.4, 0.1, 0.3)

SMILES Notation: CC[C@H](C)[C@H](NC(=O)[C@H](C)NC(=O)[C@H](CCCCN)NC(=O)[C@H](CCCNC(=N)N)NC(=O)CNC(=O)[C@H](Cc1ccccc1)NC(=O)[C@H](CCCCN)NC(=O)[C@H](CCCCN)NC(=O)[C@@H](NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CCCCN)NC(=O)CNC(=O)[C@H](Cc1ccccc1)NC(=O)[C@H](CC(C)C)NC(=O)CN)[C@@H](C)CC)C(=O)N[C@@H](CO)C(=O)N[C@@H](Cc1ccc(O)cc1)C(=O)N[C@@H](C)C(=O)N[C@H](C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](C)C(=O)N[C@@H](CCCNC(=N)N)C(=O)NCC(=O)N[C@@H](CCCCN)C(=O)N[C@@H](Cc1c[nH]cn1)C(=O)O)C(C)C

1 : Won A, et al. Imaging the membrane lytic activity of bioactive peptide latarcin 2a. Biochim Biophys Acta. 2012; 1818:3072-80. doi: 10.1016/j.bbamem.2012.07.030

Paper title : Imaging the membrane lytic activity of bioactive peptide latarcin 2a.

Doi : https://doi.org/10.1016/j.bbamem.2012.07.030

Abstract : Latarcin 2a (ltc2a, GLFGKLIKKFGRKAISYAVKKARGKH-COOH) is a short linear antimicrobial and cytolytic peptide extracted from the venom of the Central Asian spider, Lachesana tarabaevi, with lytic activity against Gram-positive and Gram-negative bacteria, erythrocytes, and yeast at micromolar concentrations. Ltc2a adopts a helix-hinge-helix structure in membrane mimicking environment, whereas its derivative latarcin 2aG11A (ltc2aG11A, GLFGKLIKKFARKAISYAVKKARGKH-COOH), likely adopts a more rigid structure, demonstrates stronger nonspecific interaction with the zwitterionic membrane, and is potentially more toxic against eukaryotic cells. In this work, interactions of these two ltc2a derivatives with supported "raft" lipid bilayer (1,2-dioleoyl-sn-glycero-3-phosphocholin/egg sphingomyelin/cholesterol 40/40/20mol%) were studied by in situ atomic force microscopy in order to investigate the potential anticancer activity of the peptides since some breast and prostate cancer cell lines contain higher levels of cholesterol-rich lipid rafts than non-cancer cells. Both peptides induced reorganization of the raft model membrane by reducing line tension of the liquid ordered phase. Ltc2aG11A induced membrane thinning likely due to membrane interdigitation. Formation of large pores by the peptides in the bilayer was observed. Cholesterol was found to attenuate membrane disruption by the peptides. Finally, leakage assay showed that both peptides have similar membrane permeability toward various model membrane vesicles.