Peptide name : Omiganan MBI-226

Source/Organism : Helical peptide with a predominance of one or more amino acids tryptophane-rich

Linear/Cyclic : Linear

Chirality : L

Peptide length: 12

C-terminal modification: Linear

N-terminal modification : Amidation

Non-natural peptide information: None

Assay type : MTT/MTS assay

Assay time : 6h

Activity : 27% 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 : 1780.1299 Dalton

Aliphatic index : 0.65

Instability index : 131.933

Hydrophobicity (GRAVY) : -1.325

Isoelectric point : 12

Charge (pH 7) : 3.7591

Aromaticity : 0.333

Molar extinction coefficient (cysteine, cystine): (22000, 22000)

Hydrophobic/hydrophilic ratio : 2

hydrophobic moment : 0.4939

Missing amino acid : C,H,Q,T,M,E,F,S,D,Y,N,A,V,G

Most occurring amino acid : W

Most occurring amino acid frequency : 4

Least occurring amino acid : I

Least occurring amino acid frequency : 1

Secondary structure fraction (Helix, Turn, Sheet): (0.1, 0.1, 0.5)

SMILES Notation: CC[C@H](C)[C@H](N)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](Cc1c[nH]c2ccccc12)C(=O)N1CCC[C@H]1C(=O)N[C@@H](Cc1c[nH]c2ccccc12)C(=O)N[C@@H](Cc1c[nH]c2ccccc12)C(=O)N1CCC[C@H]1C(=O)N[C@@H](Cc1c[nH]c2ccccc12)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CCCCN)C(=O)O

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

2 : Isaacson RE. MBI-226. Micrologix/Fujisawa. Curr Opin Investig Drugs. 2003; 4:999-1003.

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.

Paper title : MBI-226. Micrologix/Fujisawa.

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

Abstract : Micrologix and Fujisawa are developing a gel formulation of MBI-226 for the potential treatment and prevention of various infections caused by both antibiotic-resistant and -sensitive bacteria. In September 2000, a phase III trial of MBI-226 for the potential prevention of catheter-related bloodstream infections was initiated.