Peptide name : Vaby A

Source/Organism : African, the Ethiopian highlands

Linear/Cyclic : Not found

Chirality : L

Peptide length: 29

C-terminal modification: Not found

N-terminal modification : Free

Non-natural peptide information: None

Assay type : Not specified

Assay time : Not found

Activity : Not found

Cell line : Not found

Cancer type : Fibrosarcoma

Other activity : Immunomodulatory activity; Antihypertensive; Anti-microbial activity; Antiviral activity

Amino acid composition bar chart :

Molecular mass : 2888.2839 Dalton

Aliphatic index : 0.403

Instability index : 45.4759

Hydrophobicity (GRAVY) : 0.0759

Isoelectric point : 5.9623

Charge (pH 7) : -0.2965

Aromaticity : 0.034

Molar extinction coefficient (cysteine, cystine): (5500, 5875)

Hydrophobic/hydrophilic ratio : 1.9

hydrophobic moment : 0.1834

Missing amino acid : H,Q,M,K,F,D,Y

Most occurring amino acid : C

Most occurring amino acid frequency : 6

Least occurring amino acid : L

Least occurring amino acid frequency : 1

Secondary structure fraction (Helix, Turn, Sheet): (0.1, 0.4, 0.2)

SMILES Notation: CC[C@H](C)[C@H](NC(=O)[C@@H]1CCCN1C(=O)[C@H](Cc1c[nH]c2ccccc12)NC(=O)[C@H](CO)NC(=O)[C@H](CS)NC(=O)[C@H](CO)NC(=O)[C@H](CS)NC(=O)CNC(=O)[C@@H]1CCCN1C(=O)[C@@H](NC(=O)[C@H](CC(N)=O)NC(=O)[C@H](CS)NC(=O)[C@@H](NC(=O)CNC(=O)CNC(=O)[C@H](C)NC(=O)[C@H](CS)NC(=O)[C@@H](NC(=O)[C@H](CCC(=O)O)NC(=O)CNC(=O)[C@H](CS)NC(=O)[C@@H](NC(=O)[C@@H]1CCCN1C(=O)[C@H](CC(C)C)NC(=O)CN)C(C)C)[C@@H](C)O)[C@@H](C)O)[C@@H](C)O)C(=O)N[C@@H](CS)C(=O)N[C@H](C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CC(N)=O)C(=O)O)[C@@H](C)O

1 : Wang G, et al. APD2: the updated antimicrobial peptide database and its application in peptide design. Nucleic Acids Res. 2009; 37:D933-7. doi: 10.1093/nar/gkn823

2 : Yeshak MY, et al. Cyclotides from an extreme habitat: characterization of cyclic peptides from Viola abyssinica of the Ethiopian highlands. J Nat Prod. 2011; 74:727-31. doi: 10.1021/np100790f

Paper title : APD2: the updated antimicrobial peptide database and its application in peptide design.

Doi : https://doi.org/10.1093/nar/gkn823

Abstract : The antimicrobial peptide database (APD, http://aps.unmc.edu/AP/main.php) has been updated and expanded. It now hosts 1228 entries with 65 anticancer, 76 antiviral (53 anti-HIV), 327 antifungal and 944 antibacterial peptides. The second version of our database (APD2) allows users to search peptide families (e.g. bacteriocins, cyclotides, or defensins), peptide sources (e.g. fish, frogs or chicken), post-translationally modified peptides (e.g. amidation, oxidation, lipidation, glycosylation or d-amino acids), and peptide binding targets (e.g. membranes, proteins, DNA/RNA, LPS or sugars). Statistical analyses reveal that the frequently used amino acid residues (>10%) are Ala and Gly in bacterial peptides, Cys and Gly in plant peptides, Ala, Gly and Lys in insect peptides, and Leu, Ala, Gly and Lys in amphibian peptides. Using frequently occurring residues, we demonstrate database-aided peptide design in different ways. Among the three peptides designed, GLK-19 showed a higher activity against Escherichia coli than human LL-37.

Paper title : Cyclotides from an extreme habitat: characterization of cyclic peptides from Viola abyssinica of the Ethiopian highlands.

Doi : https://doi.org/10.1021/np100790f

Abstract : As part of ongoing explorations of the structural diversity of cyclotides, the cyclotide content of a native violet of the East African highlands, Viola abyssinica (which grows at altitudes up to 3400 m), was studied. Six new cyclotides, vaby A-E (1-5) and varv E (6), were isolated and characterized by employing HPLC and MS techniques and quantitative amino acid analysis. Cyclotides 1-5 were found to have new sequences, and 1-3 have a further novel feature in their sequences, an alanine moiety in loop 2. Two of the cyclotides (1 and 4) also exhibited cytotoxic properties in a flourometric microculture cytotoxicity assay. The findings corroborate the hypothesis that investigating the cyclotide contents of violets growing in diverse environments is a promising approach for extending our knowledge of both the structural and biological diversity of cyclotides.