Peptide name : Viscotoxin A1

Source/Organism : Seeds, European mistletoe

Linear/Cyclic : Not found

Chirality : L

Peptide length: 46

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 : Colorectal cancer

Other activity : Not found

Amino acid composition bar chart :

Molecular mass : 4916.5976 Dalton

Aliphatic index : 0.467

Instability index : 41.6478

Hydrophobicity (GRAVY) : -0.55

Isoelectric point : 9.3029

Charge (pH 7) : 5.6975

Aromaticity : 0.043

Molar extinction coefficient (cysteine, cystine): (2980, 3355)

Hydrophobic/hydrophilic ratio : 0.70370370

hydrophobic moment : 0.4037

Missing amino acid : W,H,Q,M,F,D,V

Most occurring amino acid : S

Most occurring amino acid frequency : 7

Least occurring amino acid : E

Least occurring amino acid frequency : 1

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

SMILES Notation: CC[C@H](C)[C@H](NC(=O)[C@H](CC(N)=O)NC(=O)[C@H](CCCNC(=N)N)NC(=O)CNC(=O)[C@@H](NC(=O)[C@@H](NC(=O)[C@H](CC(N)=O)NC(=O)[C@@H]1CCCN1C(=O)[C@H](CS)NC(=O)[C@H](CS)NC(=O)[C@H](CO)NC(=O)[C@@H](N)CCCCN)[C@@H](C)O)[C@@H](C)O)C(=O)N[C@@H](Cc1ccc(O)cc1)C(=O)N[C@@H](CC(N)=O)C(=O)N[C@H](C(=O)N[C@@H](CS)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CC(C)C)C(=O)N[C@H](C(=O)NCC(=O)N[C@@H](CO)C(=O)N[C@@H](CO)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CCC(=O)O)C(=O)N[C@H](C(=O)N[C@@H](CS)C(=O)N[C@@H](C)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CO)C(=O)NCC(=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](CO)C(=O)N[C@@H](C)C(=O)N[C@@H](CO)C(=O)N[C@H](C(=O)N[C@@H](CS)C(=O)N1CCC[C@H]1C(=O)N[C@@H](CO)C(=O)N[C@@H](CC(N)=O)C(=O)N[C@@H](Cc1ccc(O)cc1)C(=O)N1CCC[C@H]1C(=O)N[C@@H](CCCCN)C(=O)O)[C@@H](C)O)[C@@H](C)CC)[C@@H](C)CC)[C@@H](C)O)[C@@H](C)O)[C@@H](C)O

1 : Orrù S, et al. Amino acid sequence, S-S bridge arrangement and distribution in plant tissues of thionins from Viscum album. Biol Chem. 1997; 378:989-96. doi: 10.1515/bchm.1997.378.9.989

Paper title : Amino acid sequence, S-S bridge arrangement and distribution in plant tissues of thionins from Viscum album.

Doi : https://doi.org/10.1515/bchm.1997.378.9.989

Abstract : The complete primary structure of a cytotoxic 5 kDa polypeptide, viscotoxin A1, isolated from Viscum album L., has been determined by combining classical Edman degradation methodology with advanced mass spectrometric procedures. The same integrated approach allowed correction of the sequence of viscotoxin A2 and definition of the pattern of the disulfide bridges. The arrangement of the cysteine pairing was determined as Cys3-Cys40, Cys4-Cys32 and Cys16-Cys26. The primary structure of viscotoxin A1 shares a high degree of similarity with the known viscotoxins and more generally with the plant alpha- and beta-thionins. The pattern of S-S bridges determined for viscotoxin A2 and A1 is similar to that inferred by X-ray and NMR analysis in crambin and related to that present in alpha-purothionin and beta-hordothionin, thus indicating a highly conserved organization of the S-S pairings within the entire family. This arrangement of S-S bridges describes a peculiar structural motif, indicated as 'concentric motif', which is suggested to stabilize a common structure occurring in various small proteins able to interact with cell membranes. The distribution of the new variant toxin in different mistletoe subspecies was investigated. Viscotoxin A1 is abundant in the seeds of the three European subspecies of V. album whereas it represents a minor component in the shoots.