Peptide name : B1OS-D-L

Source/Organism : B-1OS

Linear/Cyclic : Linear

Chirality : Mix

Peptide length: 24

C-terminal modification: Linear

N-terminal modification : Free

Non-natural peptide information:

Assay type : MTT assay

Assay time : 24-h

Activity : IC50 = 3.17 µM

Cell line : MCF-7

Cancer type : Breast Cancer

Other activity : Antimicrobial

Amino acid composition bar chart :

Molecular mass : 2632.2802 Dalton

Aliphatic index : 1.137

Instability index : 28.6042

Hydrophobicity (GRAVY) : 0.9458

Isoelectric point : 9.8507

Charge (pH 7) : 3.7373

Aromaticity : 8.333

Molar extinction coefficient (cysteine, cystine): (2, 1)

Hydrophobic/hydrophilic ratio : 2.2857

hydrophobic moment : 0.0117

Missing amino acid : D,E,H,M,Q,W,Y

Most occurring amino acid : I

Most occurring amino acid frequency : 3

Least occurring amino acid : l

Least occurring amino acid frequency : 1

Secondary structure fraction (Helix, Turn, Sheet): (33., 20., 45.)

SMILES Notation: CC[C@H](C)[C@H](NC(=O)[C@H](CC(C)C)NC(=O)[C@@H]1CCCN1C(=O)[C@H](CC(C)C)NC(=O)[C@@H](N)Cc1ccccc1)C(=O)N[C@@H](C)C(=O)N[C@@H](CO)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](C)C(=O)NCC(=O)N[C@@H](CC(N)=O)C(=O)N[C@H](C(=O)N[C@H](C(=O)N1CCC[C@H]1C(=O)N[C@@H](CCCCN)C(=O)N[C@H](C(=O)N[C@@H](Cc1ccccc1)C(=O)N[C@@H](CS)C(=O)N[C@@H](CCCCN)C(=O)N[C@H](C(=O)N[C@H](C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CS)C(=O)O)[C@@H](C)O)[C@@H](C)CC)[C@@H](C)CC)C(C)C)C(C)C

1 : Yao A, et al. Modification Strategy of D-leucine Residue Addition on a Novel Peptide from Odorrana schmackeri, with Enhanced Bioactivity and In Vivo Efficacy. Toxins (Basel). 2021; 13:(unknown pages). doi: 10.3390/toxins13090611

Paper title : Modification Strategy of D-leucine Residue Addition on a Novel Peptide from Odorrana schmackeri, with Enhanced Bioactivity and In Vivo Efficacy.

Doi : https://doi.org/10.3390/toxins13090611

Abstract : Brevinins are a well-characterised, frog-skin-derived, antimicrobial peptide (AMP) family, but their applications are limited by high cytotoxicity. In this study, a wild-type des-Leu2 brevinin peptide, named brevinin-1OS (B1OS), was identified from Odorrana schmackeri. To explore the significant role of the leucine residue at the second position, two variants, B1OS-L and B1OS-D-L, were designed by adding L-leucine and D-leucine residues at this site, respectively. The antibacterial and anticancer activities of B1OS-L and B1OS-D-L were around ten times stronger than the parent peptide. The activity of B1OS against the growth of Gram-positive bacteria was markedly enhanced after modification. Moreover, the leucine-modified products exerted in vivo therapeutic potential in an methicillin-resistant Staphylococcus aureus (MRSA)-infected waxworm model. Notably, the single substitution of D-leucine significantly increased the killing speed on lung cancer cells, where no viable H838 cells survived after 2 h of treatment with B1OS-D-L at 10 μM with low cytotoxicity on normal cells. Overall, our study suggested that the conserved leucine residue at the second position from the N-terminus is vital for optimising the dual antibacterial and anticancer activities of B1OS and proposed B1OS-D-L as an appealing therapeutic candidate for development.