Peptide name : L-K6

Source/Organism : Temporin 1CEb analogue

Linear/Cyclic : Linear

Chirality : L

Peptide length: 13

C-terminal modification: Linear

N-terminal modification : Amidation

Non-natural peptide information:

Assay type : MTT assay

Assay time : 24-h

Activity : IC50 = 31 μM

Cell line : MCF-7

Cancer type : Breast Cancer

Other activity : Antimicrobial and Anticancer

Amino acid composition bar chart :

Molecular mass : 1553.072 Dalton

Aliphatic index : 1.8

Instability index : -15.138

Hydrophobicity (GRAVY) : 0.0538

Isoelectric point : 10.699

Charge (pH 7) : 5.7541

Aromaticity : 0

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

Hydrophobic/hydrophilic ratio : 0.8571

hydrophobic moment : 2.3229

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

Most occurring amino acid : K

Most occurring amino acid frequency : 6

Least occurring amino acid : S

Least occurring amino acid frequency : 1

Secondary structure fraction (Helix, Turn, Sheet): (69., 7.6, 46.)

SMILES Notation: CC[C@H](C)[C@H](N)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCCCN)C(=O)N[C@H](C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CO)C(=O)N[C@@H](CCCCN)C(=O)N[C@H](C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CCCCN)C(=O)O)[C@@H](C)CC)[C@@H](C)CC

1 : Wang C, et al. Cell surface binding, uptaking and anticancer activity of L-K6, a lysine/leucine-rich peptide, on human breast cancer MCF-7 cells. Sci Rep. 2017; 7:8293. doi: 10.1038/s41598-017-08963-2

Paper title : Cell surface binding, uptaking and anticancer activity of L-K6, a lysine/leucine-rich peptide, on human breast cancer MCF-7 cells.

Doi : https://doi.org/10.1038/s41598-017-08963-2

Abstract : Cell surface binding and internalization are critical for the specific targeting and biofunctions of some cationic antimicrobial peptides (CAPs) with anticancer activities. However, the detailed cellular process for CAPs interacting with cancer cells and the exact molecular basis for their anticancer effects are still far from being fully understood. In the present study, we examined the cell surface binding, uptaking and anti-cancer activity of L-K6, a lysine/leucine-rich CAP, in human MCF-7 breast cancer cells. We found that L-K6 preferentially interact with MCF-7 cells. This tumor-targeting property of L-K6 might be partially due to its interactions with the surface exposed and negatively charged phosphatidylserine. Subsequently, L-K6 could internalize into MCF-7 cells mainly through a clathrin-independent macropinocytosis, without significant cell surface disruption. Finally, the internalized L-K6 induced a dramatic nuclear damage and MCF-7 cell death, without significant cytoskeleton disruption and mitochondrial impairment. This cytotoxicity of L-K6 against MCF-7 cancer cells could be further confirmed by using a mouse xenograft model. In summary, all these findings outlined the cellular process and cytotoxicity of L-K6 in MCF-7 cancer cells, and might help understand the complicated interactions between CAPs and cancer cells.