Peptide name : Buforin2

Source/Organism : Asiatic toad

Linear/Cyclic : Linear

Chirality : L

Peptide length: 21

C-terminal modification: Linear

N-terminal modification : Amidation

Non-natural peptide information: None

Assay type : MTT/MTS assay

Assay time : 6h

Activity : 5% Cytotoxicity at 0.5 µg/ml

Cell line : U-937

Cancer type : Lymphoma cancer

Other activity : Anti-microbial activity

Amino acid composition bar chart :

Molecular mass : 2434.8474 Dalton

Aliphatic index : 0.881

Instability index : 84.1952

Hydrophobicity (GRAVY) : -0.638

Isoelectric point : 12

Charge (pH 7) : 5.4843

Aromaticity : 0.047

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

Hydrophobic/hydrophilic ratio : 0.90909090

hydrophobic moment : 0.7961

Missing amino acid : C,W,M,I,E,D,Y,N

Most occurring amino acid : R

Most occurring amino acid frequency : 5

Least occurring amino acid : T

Least occurring amino acid frequency : 1

Secondary structure fraction (Helix, Turn, Sheet): (0.2, 0.2, 0.3)

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

1 : Park CB, et al. A novel antimicrobial peptide from Bufo bufo gargarizans. Biochem Biophys Res Commun. 1996; 218:408-13. doi: 10.1006/bbrc.1996.0071

2 : Koszałka P, et al. Antitumor activity of antimicrobial peptides against U937 histiocytic cell line. Acta Biochim Pol. 2011; 58:111-7.

Paper title : A novel antimicrobial peptide from Bufo bufo gargarizans.

Doi : https://doi.org/10.1006/bbrc.1996.0071

Abstract : A potent and structurally novel antimicrobial peptide was isolated and characterized from the stomach tissue of Bufo bufo gargarizans, an Asian toad. The 39-amino acid peptide, named buforin I, was purified to homogeneity by heparin-affinity column and reverse-phase HPLC. The amino acid sequence of buforin I was identical in 37 of 39 amino-terminal residues of Xenopus histone H2A. The buforin I showed strong antimicrobial activities in vitro against a broad-spectrum of microorganisms and was found to be more potent than magainin 2. In addition, a 21-amino acid peptide, named buforin II, which was derived from buforin I, showed more potent antimicrobial activities than buforin I.

Paper title : Antitumor activity of antimicrobial peptides against U937 histiocytic cell line.

Doi : https://doi.org/Not available

Abstract : We investigated cytotoxic activity of antimicrobial peptides of different origin (both naturally occurring and synthetic), structure and known mechanisms of action against human histiocytic lymphoma cell line U937. The strongest cytotoxic activity against U937 cell line was shown by Pexiganan MSI-78, followed by Citropin 1.1, Protegrin 1 and a synthetic lipopeptide, N-α-palmitoyl-L-lysyl-L-lysine amide (Pal-Lys-Lys-NH₂). The cytotoxic activity of the peptides was more dependent on the time of incubation than concentration. Only for the lipopeptide, whose mode of action was restricted to disruption of electric potential of the cell membrane, the correlation between cytotoxicity and concentration was almost linear. The high cytotoxicity of Pexiganan MSI-78, Protegrin 1 and the lipopeptide could be basically explained by their membranolytic activity leading to necrosis. However, in the case of Citropin 1.1, the cell membrane integrity was disrupted only slightly and independently of the peptide concentration. Therefore, some other mechanism of action might be responsible for its strong dose-dependent cytotoxic activity, e.g., membranolytic activity leading to apoptosis. Furthermore, TNF-α production due to LPS (lipopolysaccharide) stimulation was suppressed by the presence of Citropin 1.1, Pexiganan MSI-78 or Protegrin 1, but not by Buforin 2 or the lipopeptide. Our experiments have shown that cytotoxic activity is not limited to some specific molecular structure of a peptide, but rather to the length of the peptide chain as it is likely to affect the efficiency of the tumor cell membrane disruption and interaction with LPS.