Peptide name : Cycloviolacin O2

Source/Organism : Not found

Linear/Cyclic : Not found

Chirality : L

Peptide length: 30

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 : Not found

Other activity : Not found

Amino acid composition bar chart :

Molecular mass : 3164.7438 Dalton

Aliphatic index : 0.746

Instability index : 25.0833

Hydrophobicity (GRAVY) : 0.4433

Isoelectric point : 8.3338

Charge (pH 7) : 1.7005

Aromaticity : 0.066

Molar extinction coefficient (cysteine, cystine): (6990, 7365)

Hydrophobic/hydrophilic ratio : 1.72727272

hydrophobic moment : 0.0591

Missing amino acid : H,T,Q,M,F,D,L

Most occurring amino acid : C

Most occurring amino acid frequency : 6

Least occurring amino acid : E

Least occurring amino acid frequency : 1

Secondary structure fraction (Helix, Turn, Sheet): (0.1, 0.3, 0.2)

SMILES Notation: CC[C@H](C)[C@H](NC(=O)[C@H](C)NC(=O)[C@H](CO)NC(=O)[C@H](CO)NC(=O)[C@@H](NC(=O)[C@H](CS)NC(=O)[C@@H]1CCCN1C(=O)[C@@H](NC(=O)[C@H](Cc1c[nH]c2ccccc12)NC(=O)[C@@H](NC(=O)[C@H](CS)NC(=O)[C@H](CO)NC(=O)[C@H](CCC(=O)O)NC(=O)CNC(=O)[C@H](CS)NC(=O)[C@@H]1CCCN1C(=O)[C@@H](NC(=O)CN)[C@@H](C)CC)C(C)C)[C@@H](C)CC)[C@@H](C)CC)C(=O)NCC(=O)N[C@@H](CS)C(=O)N[C@@H](CO)C(=O)N[C@@H](CS)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CO)C(=O)N[C@@H](CCCCN)C(=O)N[C@H](C(=O)N[C@@H](CS)C(=O)N[C@@H](Cc1ccc(O)cc1)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CC(N)=O)C(=O)O)C(C)C

1 : Craik DJ, et al. Plant cyclotides: A unique family of cyclic and knotted proteins that defines the cyclic cystine knot structural motif. J Mol Biol. 1999; 294:1327-36. doi: 10.1006/jmbi.1999.3383

Paper title : Plant cyclotides: A unique family of cyclic and knotted proteins that defines the cyclic cystine knot structural motif.

Doi : https://doi.org/10.1006/jmbi.1999.3383

Abstract : Several macrocyclic peptides ( approximately 30 amino acids), with diverse biological activities, have been isolated from the Rubiaceae and Violaceae plant families over recent years. We have significantly expanded the range of known macrocyclic peptides with the discovery of 16 novel peptides from extracts of Viola hederaceae, Viola odorata and Oldenlandia affinis. The Viola plants had not previously been examined for these peptides and thus represent novel species in which these unusual macrocyclic peptides are produced. Further, we have determined the three-dimensional structure of one of these novel peptides, cycloviolacin O1, using (1)H NMR spectroscopy. The structure consists of a distorted triple-stranded beta-sheet and a cystine-knot arrangement of the disulfide bonds. This structure is similar to kalata B1 and circulin A, the only two macrocyclic peptides for which a structure was available, suggesting that despite the sequence variation throughout the peptides they form a family in which the overall fold is conserved. We refer to these peptides as the cyclotide family and their embedded topology as the cyclic cystine knot (CCK) motif. The unique cyclic and knotted nature of these molecules makes them a fascinating example of topologically complex proteins. Examination of the sequences reveals they can be separated into two subfamilies, one of which tends to contain a larger number of positively charged residues and has a bracelet-like circularization of the backbone. The second subfamily contains a backbone twist due to a cis-Pro peptide bond and may conceptually be regarded as a molecular Moebius strip. Here we define the structural features of the two apparent subfamilies of the CCK peptides which may be significant for the likely defense related role of these peptides within plants.