Peptide name : CIGB-552

Source/Organism : Synthetic

Linear/Cyclic : Linear

Chirality : Mix

Peptide length: 20

C-terminal modification: Linear

N-terminal modification : Free

Non-natural peptide information:

Assay type : Sulforhodamine B assay

Assay time : 48-h

Activity : IC50 = 379.1 ± 8.6 µM

Cell line : MCF-7

Cancer type : Breast Cancer

Other activity : Anticancer

Amino acid composition bar chart :

Molecular mass : 2647.1773 Dalton

Aliphatic index : 0.245

Instability index : 23.56

Hydrophobicity (GRAVY) : -1.315

Isoelectric point : 11.763

Charge (pH 7) : 7.8413

Aromaticity : 25

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

Hydrophobic/hydrophilic ratio : 0.6364

hydrophobic moment : 0.3757

Missing amino acid : C,D,E,L,M,N,P,Q,S,V

Most occurring amino acid : K

Most occurring amino acid frequency : 5

Least occurring amino acid : H

Least occurring amino acid frequency : 1

Secondary structure fraction (Helix, Turn, Sheet): (35, 10, 40)

SMILES Notation: CC[C@H](C)[C@H](NC(=O)[C@H](CCCNC(=N)N)NC(=O)[C@H](C)NC(=O)[C@@H](N)Cc1c[nH]cn1)C(=O)N[C@@H](CCCCN)C(=O)N1CCC[C@H]1C(=O)N[C@H](C(=O)N[C@@H](Cc1ccccc1)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](Cc1c[nH]c2ccccc12)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](Cc1ccc(O)cc1)C(=O)N[C@@H](CCCCN)C(=O)NCC(=O)N[C@@H](CCCCN)C(=O)N[C@@H](Cc1ccccc1)C(=O)N[C@@H](Cc1c[nH]c2ccccc12)C(=O)O)[C@@H](C)O

1 : Astrada S, et al. Comparative analysis reveals amino acids critical for anticancer activity of peptide CIGB-552. J Pept Sci. 2016; 22:711-722. doi: 10.1002/psc.2934

Paper title : Comparative analysis reveals amino acids critical for anticancer activity of peptide CIGB-552.

Doi : https://doi.org/10.1002/psc.2934

Abstract : Because of resistance development by cancer cells against current anticancer drugs, there is a considerable interest in developing novel antitumor agents. We have previously demonstrated that CIGB-552, a novel cell-penetrating synthetic peptide, was effective in reducing tumor size and increasing lifespan in tumor-bearing mice. Studies of protein-peptide interactions have shown that COMMD1 protein is a major mediator of CIGB-552 antitumor activity. Furthermore, a typical serine-protease degradation pattern for CIGB-552 in BALB/c mice serum was identified, yielding peptides which differ from CIGB-552 in size and physical properties. In the present study, we show the results obtained from a comparative analysis between CIGB-552 and its main metabolites regarding physicochemical properties, cellular internalization, and their capability to elicit apoptosis in MCF-7 cells. None of the analyzed metabolites proved to be as effective as CIGB-552 in promoting apoptosis in MCF-7. Taking into account these results, it seemed important to examine their cell-penetrating capacity and interaction with COMMD1. We show that internalization, a lipid binding-dependent process, is impaired as well as metabolite-COMMD1 interaction, key component of the apoptotic mechanism. Altogether, our results suggest that features conferred by the amino acid sequence are decisive for CIGB-552 biological activity, turning it into the minimal functional unit. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.