Peptide name : Phylloseptin-PHa

Source/Organism : Northern orange-legged leaf frog

Linear/Cyclic : Not found

Chirality : Not found

Peptide length: 19

C-terminal modification: Not found

N-terminal modification : Amidation

Non-natural peptide information: None

Assay type : MTT assay, Lactate dehydrogenase (LDH) assay

Assay time : Not found

Activity : LD50 : < 5 µM

Cell line : MDA-MB-435

Cancer type : Melanocyte

Other activity : Anti-microbial activity

Amino acid composition bar chart :

Molecular mass : 1942.2604 Dalton

Aliphatic index : 1.442

Instability index : 12.6368

Hydrophobicity (GRAVY) : 1.5

Isoelectric point : 6.7411

Charge (pH 7) : -0.1527

Aromaticity : 0.105

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

Hydrophobic/hydrophilic ratio : 2.8

hydrophobic moment : 1.346

Missing amino acid : C,R,W,Q,T,M,E,K,D,Y,G

Most occurring amino acid : A

Most occurring amino acid frequency : 5

Least occurring amino acid : P

Least occurring amino acid frequency : 1

Secondary structure fraction (Helix, Turn, Sheet): (0.4, 0.2, 0.4)

SMILES Notation: CC[C@H](C)[C@H](NC(=O)[C@H](C)NC(=O)[C@H](C)NC(=O)[C@@H]1CCCN1C(=O)[C@@H](NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CO)NC(=O)[C@H](CC(C)C)NC(=O)[C@@H](N)Cc1ccccc1)[C@@H](C)CC)C(=O)N[C@@H](CO)C(=O)N[C@@H](C)C(=O)N[C@H](C(=O)N[C@@H](CO)C(=O)N[C@@H](C)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](C)C(=O)N[C@@H](CC(N)=O)C(=O)N[C@@H](Cc1c[nH]cn1)C(=O)N[C@@H](Cc1ccccc1)C(=O)O)C(C)C

1 : Liu Y, et al. Structure-activity relationship of an antimicrobial peptide, Phylloseptin-PHa: balance of hydrophobicity and charge determines the selectivity of bioactivities. Drug Des Devel Ther. 2019; 13:447-458. doi: 10.2147/DDDT.S191072

Paper title : Structure-activity relationship of an antimicrobial peptide, Phylloseptin-PHa: balance of hydrophobicity and charge determines the selectivity of bioactivities.

Doi : https://doi.org/10.2147/DDDT.S191072

Abstract : BACKGROUND: Antimicrobial peptides (AMPs) from the skin secretions of amphibians are now considered as a potential alternative to conventional antibiotics. Phylloseptins are a family of AMPs identified in the skin secretions of Phyllomedusinae tree frogs which exhibit highly conserved structural characteristics. This study examines the structure-activity relationship of the newly discovered phylloseptin, Phylloseptin-PHa (PSPHa) from Pithecopus hypochondrialis. MATERIALS AND METHODS: PSPHa and modified analogs were produced by solid phase synthesis and purified by reverse-phase HPLC. Rationally designed modified analogs incorporating changes in significant physicochemical parameters such as hydrophobicity, hydrophobic moment and net charge were investigated to determine their influence on secondary structure, antimicrobial activity, membrane permeabilization and cytotoxicity. RESULTS: Overall, we found that when rationally designing AMPs by altering their primary structure it is important to keep a balance between hydrophobicity and charge. CONCLUSION: This study provides new insights which will help in the future development of AMPs as alternatives to conventional antibiotics for the treatment of Staphylococcus aureus and methicillin-resistant S. aureus infections.