cycloviolacin O2(21) Protein Card

General Information
Name cycloviolacin O2
Alternative name(s) cO2,CyO2
Class Cyclotide
Technique MS,NGS
Average Mass 3140.69
Monoisotopic Mass 3138.37
m/z M+H 3140.69
ProteinType Wild type
Organism Viola odorata
Hybanthus enneaspermus
Viola baoshanensis
Viola biflora
Viola philippica
Viola uliginosa
Viola arcuata
Viola austrosinensis
Viola anagae
Notes <i>H. enneaspermus</i>: isolated from the plant and fully sequenced by MS/MS (Du et al., 2020).
Cyclic Yes

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
Cancer Cell Toxicity
CyO2, CyO13, kalata B1, and varv peptide A exhibited dose-dependent cytotoxicity in MTT assays with IC50 values of 2.15-7.93 uM against human brain astrocytoma cells (U-87 MG) and human bone marrow derived neuroblastoma cells (SH-SY5Y). CyO2 and varv peptide A also sensitized SH-SY5Y and U-87 MG cells to temozolomide (TMZ) which is the only effective chemotherapeutic drug used to treat glioblastoma multiforme (GBM). [...]Gerlach,S.L. et al. (2022) J Nat Prod 85:34-46
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
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
Glutamic acid mutant had reduced activity [...]Herrmann A et al. (2006) Cell Mol Life Sci 63:235-45
Cytotoxicity of cyO2, cyO9, hyen D and kB5 and their mutants on HeLa cells. [...]Huang,Y.H. et al. (2021) Molecules 26:0-0
Cycloviolacin O2 showed antitumor effects are minor or absent at tolerable (sublethal) doses, and cycloviolacin O2 has a very abrupt in vivo toxicity profile, with lethality after single injection at 2 mg/kg, but no signs of discomfort to the animals at 1.5 mg/kg. Repeated dosing of 1 mg/kg gave a local-inflammatory reaction at the site of injection after 2–3 days; lower doses were without complications. [...]Burman et al. (2010) Peptide Science 94:626-634
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
Anti-barnacle activity shown for cycloviolacin O2 [...]Goransson U et al. (2004) J Nat Prod 67:1287-90
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
Cycloviolacin O2 showed antibacterial activity against A. baumannii. [...]Kirkpatrick et al. (2017) Analytical chemistry 89:1194-1201
CyO2,CyO3,CyO13,CyO19 have deterrent activity on M.persicae. [...]Dancewicz et al. (2020) Journal of Insect Physiology 122:104025-0
Membrane Binding Assay
[I11L] mutants of cyO2, cyO9, hyen D and kalata B5 exhibited equipotent binding to the POPC/POPE(80:20) model membrane compared to their wild-type counterparts whereas the [I11G] mutants showed no binding or weak affinity to membranes. [...]Huang,Y.H. et al. (2021) Molecules 26:0-0
Tb3+/DPA Liposome Assay on cycloviolacin O2 showed an effect within minutes [...]Svangard E et al. (2007) J Nat Prod 70:643-647

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
Zhang, J., Li, J., Huang, Z., Yang, B., Zhang, X., Li, D., Craik, D.J., Baker, A.J., Shu, W. and Liao, B. (2015) Transcriptomic screening for cyclotides and other cysteine-rich proteins in the metallophyte Viola baoshanensis. Journal of plant physiology 178:17-26
Slazak, B., Jacobsson, E., Kuta, E. and Göransson, U. (2015) Exogenous plant hormones and cyclotide expression in Viola uliginosa (Violaceae Phytochemistry 117:527-536
Kirkpatrick, C.L., Broberg, C.A., McCool, E.N., Lee, W.J., Chao, A., McConnell, E.W., Pritchard, D.A., Hebert, M., Fleeman, R., Adams, J. and Jamil, A. (2017) The "
Pipeline for Natural Product Bioactive Peptide Discovery Analytical chemistry 89:1194-1201
Burman, R., Svedlund, E., Felth, J., Hassan, S., Herrmann, A., Clark, R.J., Craik, D.J., Bohlin, L., Claeson, P., Göransson, U. and Gullbo, J (2010) Evaluation of toxicity and antitumor activity of cycloviolacin O2 in mice Peptide Science 94:626-634
Dancewicz, K., Slazak, B., Kiełkiewicz, M., Kapusta, M., Bohdanowicz, J. and Gabryś, B. (2020) Behavioral and physiological effects of Viola spp. cyclotides on Myzus persicae (Sulz.) Journal of Insect Physiology 122:104025-0
Du,Q., Chan,L.Y., Gilding,E.K., Henriques,S.T., Condon,N.D., Ravipati,A.S., Kaas,Q., Huang,Y.H. and Craik,D.J. (2020) Discovery and mechanistic studies of cytotoxic cyclotides from the medicinal herb Hybanthus enneaspermus. J Biol Chem 295:10911-10925
Dang,T.T., Chan,L.Y., Huang,Y.H., Nguyen,L.T.T., Kaas,Q., Huynh,T. and Craik,D.J. (2020) Exploring the Sequence Diversity of Cyclotides from Vietnamese Viola Species. J Nat Prod 83:1817-1828
Slazak,B., Kaltenböck,K., Steffen,K., Rogala,M., Rodríguez-Rodríguez,P., Nilsson,A., Shariatgorji,R. and Göransson,U. (2021) Cyclotide host-defense tailored for species and environments in violets from the Canary Islands. Sci Rep 11:12452-0
Huang,Y.H., Du,Q., Jiang,Z., King,G.J., Collins,B.M. and Craik,D.J. (2021) Enabling Efficient Folding and High-Resolution Crystallographic Analysis of Bracelet Cyclotides. Molecules 26:0-0
Gerlach,S.L., Dunlop,R.A., Metcalf,J.S., Banack,S.A., and Cox,P.A. (2022) Cyclotides Chemosensitize Glioblastoma Cells to Temozolomide. J Nat Prod 85:34-46

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