cycloviolacin O2(21) Protein Card

General Information
Name cycloviolacin O2
Alternative name(s) cO2
Sequence GIPCGESCVWIPCISSAIGCSCKSKVCYRN
Class Cyclotide
Technique MS
Average Mass 3140.69
Monoisotopic Mass 3138.37
m/z M+H 3140.69
ProteinType Wild type
Parent
Organism Viola odorata
Viola biflora
Viola philippica
Notes
Cyclic Yes

Assay
Anti-barnacle
Anti-barnacle activity shown for cycloviolacin O2 [...]Goransson U et al. (2004) J Nat Prod 67:1287-90
Hemolytic
At a concentration of 25 ºM, a more than 6-fold difference exists between the most hemolyticcyclotide, cycloviolacin O24 (~75% hemolysis), and the least hemolytic cyclotide cycloviolacin O14 (~11% hemolysis). The sensitivity of hemolytic activity to variations in the peptide sequence is evident when comparing cycloviolacin O2 and O13. Here, the only sequence deviation is a single residue substitution of a serine in loop 3 of O2 (HD50 ~36 ºM) to an alanine in the homologous position in O13 (HD50 ~11 ºM). The loss of this single hydroxy group changes the HD50 more than three-fold. [...]Ireland DC et al. (2006) Biochem J. 400:1-12
Cancer Cell Toxicity
Psyle A, psyle C, psyle E and cycloviolacin O2 shown to possess cytotoxic activity in cancer cells. [...]Gerlach SL et al. (2010) Biopolymers 94:617-625
Studies using calcein assay and HeLa cells showed that at 10 uM, the increase in calcein leakage is very rapid. [...]Svangard E et al. (2007) J Nat Prod 70:643-647
Cell viability and morphology studies on the human lymphoma cell line U-937 GTB showed that cells exposed to cycloviolacin O2 displayed disintegrated cell membranes within 5 min. [...]Svangard E et al. (2007) J Nat Prod 70:643-647
All three cyclotides, varv A, varv F, and cycloviolacin O2, exhibited strong cytotoxic activities, which varied in a dose-dependent manner. [...]Lindholm P et al. (2002) Mol Cancer Ther 1:365-369
Glutamic acid mutant had reduced activity [...]Herrmann A et al. (2006) Cell Mol Life Sci 63:235-45
Membrane Binding Assay
Tb3+/DPA Liposome Assay on cycloviolacin O2 showed an effect within minutes [...]Svangard E et al. (2007) J Nat Prod 70:643-647
Nematocidal
Motility affected by cyclotides [...]Colgrave ML et al. (2008) Chembiochem 9:1939-1945
A range of natural variants were selected based on net charge and/or hydrophobicity and were tested alongside the prototypic cyclotide kB1 in larval development assays with H. contortus and T. colubriformis. [...]Colgrave ML et al. (2008) Chembiochem 9:1939-1945

References
Goransson U, Sjogren M, Svangard E, Claeson P, Bohlin L (2004) Reversible antifouling effect of the cyclotide cycloviolacin O2 against barnacles. J Nat Prod 67:1287-90
Dutton JL, Renda RF, Waine C, Clark RJ, Daly NL, Jennings CV, Anderson MA, Craik DJ (2004) Conserved structural and sequence elements implicated in the processing of gene-encoded circular proteins. J Biol Chem 279:46858-67
Trabi M, Craik DJ (2004) Tissue-specific expression of head-to-tail cyclized miniproteins in Violaceae and structure determination of the root cyclotide Viola hederacea root cyclotide1. Plant Cell 16:2204-16
Craik DJ, Daly NL, Bond T, Waine C (1999) Plant cyclotides: A unique family of cyclic and knotted proteins that defines the cyclic cystine knot structural motif. J Mol Biol 294:1327-36
Ireland DC, Colgrave ML, Craik DJ (2006) A novel suite of cyclotides from Viola odorata: sequence variation and the implications for structure, function and stability. Biochem J. 400:1-12
Herrmann A, Svangard E, Claeson P, Gullbo J, Bohlin L, Goransson U (2006) Key role of glutamic acid for the cytotoxic activity of the cyclotide cycloviolacin O2. Cell Mol Life Sci 63:235-45
Lindholm P, Goransson U, Johansson S, Claeson P, Gullbo J, Larsson R, Bohlin L, Backlund A (2002) Cyclotides: a novel type of cytotoxic agents. Mol Cancer Ther 1:365-369
Svangard E, Burman R, Gunasekera S, Lovborg H, Gullbo J, Goransson U (2007) Mechanism of action of cytotoxic cyclotides: cycloviolacin O2 disrupts lipid membranes. J Nat Prod 70:643-647
Herrmann A, Burman R, Mylne JS, Karlsson G, Gullbo J, Craik DJ, Clark RJ, Goransson U (2008) The alpine violet, Viola biflora, is a rich source of cyclotides with potent cytotoxicity Phytochemistry 69:939-952
Tang J, Wang CK, Pan X, Yan H, Zeng G, Xu W, He W, Daly NL, Craik DJ, Tan N (2010) Isolation and characterization of cytotoxic cyclotides from Viola tricolor. Peptides 31:1434-1440
Gerlach SL, Rathinakumar R, Chakravarty G, Göransson U, Wimley WC, Darwin SP, Mondal D (2010) Anticancer and chemosensitizing abilities of cycloviolacin 02 from Viola odorata and psyle cyclotides from Psychotria leptothyrsa. Biopolymers 94:617-625
He,W., Chan,L.Y., Zeng,G., Daly,N.L., Craik,D.J. and Tan,N. (2011) Isolation and characterization of cytotoxic cyclotides from Viola philippica. Peptides 32:1719-1723
Burman,R., Strömstedt,A.A., Malmsten,M. and Göransson,U. (2011) Cyclotide-membrane interactions: defining factors of membrane binding, depletion and disruption. Biochim. Biophys. Acta 1808:2665-2673
Slazak, B., Kapusta, M., Strömstedt, A.A., Słomka, A., Krychowiak, M., Shariatgorji, M., Andrén, P.E., Bohdanowicz, J., Kuta, E. and Göransson, U. (2018) How Does the Sweet Violet (Viola odorata L.) Fight Pathogens and Pests - Cyclotides as a Comprehensive Plant Host Defense System Frontiers in plant science 9:0-0

Cross-references
Nucleic acids cyclotide c3 precursor
Structure Solution structure of cycloviolacin O2.
Solution structure of the cyclotide cycloviolacin O2
Links SwissProt P58434

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