Peptide name : P160

Source/Organism : Not found

Linear/Cyclic : Not found

Chirality : D

Peptide length: 12

C-terminal modification: Not found

N-terminal modification : Free

Non-natural peptide information: None

Assay type : MTT cytotoxicity assay

Assay time : 48h

Activity : IC50 : 14.2 ± 1.5 μM

Cell line : MCF-7

Cancer type : Breast cancer

Other activity : Not found

Amino acid composition bar chart :

Molecular mass : 1536.794 Dalton

Aliphatic index : 0.65

Instability index : 74.65

Hydrophobicity (GRAVY) : -0.2

Isoelectric point : 5.9716

Charge (pH 7) : -0.2642

Aromaticity : 0.25

Molar extinction coefficient (cysteine, cystine): (6990, 6990)

Hydrophobic/hydrophilic ratio : 2

hydrophobic moment : 0.8871

Missing amino acid : C,H,T,I,K,S,D,N,G

Most occurring amino acid : P

Most occurring amino acid frequency : 2

Least occurring amino acid : V

Least occurring amino acid frequency : 1

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

SMILES Notation: CSCC[C@H](NC(=O)[C@H](Cc1c[nH]c2ccccc12)NC(=O)[C@@H]1CCCN1C(=O)[C@@H](N)C(C)C)C(=O)N[C@@H](CCC(=O)O)C(=O)N1CCC[C@H]1C(=O)N[C@@H](C)C(=O)N[C@@H](Cc1ccc(O)cc1)C(=O)N[C@@H](CCC(N)=O)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](Cc1ccccc1)C(=O)N[C@@H](CC(C)C)C(=O)O

1 : Soudy R, et al. Breast Cancer Targeting Peptide Binds Keratin 1: A New Molecular Marker for Targeted Drug Delivery to Breast Cancer. Mol Pharm. 2017; 14:593-604. doi: 10.1021/acs.molpharmaceut.6b00652

2 : Zhang J, et al. Neuroblastoma tumor cell-binding peptides identified through random peptide phage display. Cancer Lett. 2001; 171:153-64. doi: 10.1016/s0304-3835(01)00575-4

Paper title : Breast Cancer Targeting Peptide Binds Keratin 1: A New Molecular Marker for Targeted Drug Delivery to Breast Cancer.

Doi : https://doi.org/10.1021/acs.molpharmaceut.6b00652

Abstract : The biomarkers or receptors expressed on cancer cells and the targeting ligands with high binding affinity for biomarkers play a key role in early detection and treatment of breast cancer. The breast cancer targeting peptide p160 (12-mer) and its enzymatically stable analogue 18-4 (10-mer) showed marked potential for breast cancer drug delivery using cell studies and animal models. Herein, we used affinity purification, liquid chromatography-tandem mass spectrometry, and proteomics to identify keratin 1 (KRT1) as the target receptor highly expressed on breast cancer cells for p160 peptide(s). Western blot and immunocytochemistry in MCF-7 breast cancer cells confirmed the identity of KRT1. We demonstrate that the p160 or 18-4 binding to MCF-7 breast cancer cells is dependent on the expression of KRT1, and we confirm peptide-KRT1 binding specificity using SPR experiments (K_d ∼ 1.1 μM and 0.98 μM for p160 and 18-4, respectively). Furthermore, we assessed the ability of peptide 18-4 to improve the cellular uptake and anticancer activity of a pro-apoptotic antimicrobial peptide, microcin J25 (MccJ25), in breast cancer cells. A covalent conjugate of peptide 18-4 with MccJ25 showed preferential cytotoxicity toward breast cancer cells with minimal cytotoxicity against normal HUVEC cells. The conjugate inhibited the growth of MDA-MB-435 MDR multidrug-resistant cells with an IC₅₀ comparable to that of nonresistant cells. Conjugation improved selective cellular uptake of MccJ25, and the conjugate triggered cancer cell death by apoptosis. Our findings establish KRT1 as a new marker for breast cancer targeting. Additionally, it pinpoints the potential use of antimicrobial lasso peptides as a novel class of anticancer therapeutics.

Paper title : Neuroblastoma tumor cell-binding peptides identified through random peptide phage display.

Doi : https://doi.org/10.1016/s0304-3835(01)00575-4

Abstract : Random peptide phage display libraries have been employed widely to identify protein-protein interactions, using as targets either purified proteins, intact cells, or organs. To isolate peptides that bind to human neuroblastoma cells, we have used a phage display approach with the neuroblastoma cell line WAC 2 as the target. In particular, two bacteriophages, t147 and t160, displaying peptides p147 and p160, respectively, were isolated by repeated display cycles. Binding of t147 and t160 to WAC 2 cells was abrogated by pretreatment with the peptides p147 and p160, respectively, which strongly support that cellular binding of both phages is dictated by their displayed peptides. Immunofluorescence analysis by confocal light microscopy revealed that the major proportion of t147 remains on the surface of WAC 2 cells and that only a fraction is taken up into the cells. In contrast, the vast majority of t160 is internalized. K(+) depletion reduced the number of the phages internalized by the cells to approximately 20% for t160 and to 10% for t147, indicating that the phage internalization was through receptor-mediated endocytosis. Phage t147 appears to bind to a range of tumor cell lines, including neuroblastoma, breast cancer, glioblastoma and C-cell carcinoma, but less so to non-tumor lines, such as erythrocytes, lymphocytes, monocytes and epithelial cells. Phage t160 bound to a range of neuroblastoma cell lines and a breast cancer cell line, but not to other tested cell lines. While neither of the displayed peptides conferred a narrow tissue specific binding ability, they do provide a basis for targeted drug delivery in selected experimental or natural tumor systems.