Viola arvensis<\/em>\u00a0a cyclotide containing plant. Member of the violaceae family and found in temperate regions of Australia and Europe.<\/small><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\nWith our report of the three dimensional structure of kalata B1 in 1995 and its sequence homology with the circulins and cyclopsychotride A, we became convinced that macrocyclic peptides might be more common than had earlier been thought and we began searching for other examples. Several other macrocyclic peptides were found in the late 1990s and it became clear that the peptides formed part of a family that we subsequently named the cyclotides.<\/p>\n
Several novel cyclotide sequences have been discovered in the last few years , with the known sequences now exceeding 45 and many more currently being characterized in our laboratories. A large proportion of the new cyclotides have been discovered based on their structural properties rather than biological activities. The cyclotides are relatively hydrophobic and can be readily identified from crude plant extracts by their characteristically late elution on RP-HPLC.<\/p>\n
The cyclotides described above, all come from plants in the Rubiaceae or Violaceae families but the prevalence of macrocyclic peptides has recently been expanded to include the Cucurbitaceae family. This is based on the discovery of the trypsin inhibitors MCoTI-I and MCoTI-II, 34 residue macrocyclic peptides, from Momordica cochinchinensis . They have no sequence homology to the previously characterized cyclotides, with the exception of the six cysteine residues, but are of a similar size and contain a cystine knot motif (Felizmenio-Quimio, 2001). The MCoTI peptides were originally isolated based on their trypsin inhibitory activity and are homologous to linear cystine knot peptides from the squash family of trypsin inhibitors such as EETI-II and CMTI.<\/p>\n
References<\/h2>\n
Bokesch HR, Pannell LK, Cochran PK, Sowder RC, 2nd, McKee TC and Boyd MR: A novel anti-HIV macrocyclic peptide from Palicourea condensata.\u00a0J. Nat. Prod. (2001)<\/em>\u00a064:249-250.<\/p>\nBroussalis AM, Goransson U, Coussio JD, Ferraro G, Martino V and Claeson P: First cyclotide from Hybanthus (Violaceae).\u00a0Phytochemistry<\/em>\u00a0(2001) 58:47-51.<\/p>\nClaeson P, G\ufffdransson U, Johansson S, Luijendijk T and Bohlin L: Fractionation protocol for the isolation of polypeptides from plant biomass.\u00a0J. Nat. Prod.<\/em>\u00a0(1998) 61:77-81.<\/p>\nCraik DJ, Daly NL, Bond T and Waine C: Plant cyclotides: A unique family of cyclic and knotted proteins that defines the cyclic cystine knot structural motif.\u00a0J. Mol. Biol.<\/em>\u00a0(1999) 294:1327-1336.<\/p>\nG\ufffdransson U, Luijendijk T, Johansson S, Bohlin L and Claeson P: Seven novel macrocyclic polypeptides from Viola arvensis.\u00a0J. Nat. Prod.<\/em>\u00a0(1999) 62:283-286.<\/p>\nGran L: Isolation of oxytocic peptides from Oldenlandia affinis by solvent extraction of tetraphenylborate complexes and chromatography on sephadex LH-20.\u00a0Lloydia<\/em>\u00a0(1973a) 36:207-208.<\/p>\nGran L: On the effect of a polypeptide isolated from \u201cKalata-Kalata\u201d (Oldenlandia affinis DC) on the oestrogen dominated uterus.\u00a0Acta Pharmacol. Toxicol.<\/em>\u00a0(1973b) 33:400-408.<\/p>\nGustafson KR, Sowder II RC, Henderson LE, Parsons IC, Kashman Y, Cardellina II JH, McMahon JB, Buckheit Jr. RW, Pannell LK and Boyd MR: Circulins A and B: Novel HIV-inhibitory macrocyclic peptides from the tropical tree Chassalia parvifolia.\u00a0J. Am. Chem. Soc.<\/em>\u00a0(1994) 116:9337-9338.<\/p>\nHallock YF, Sowder RCI, Pannell LK, Hughes CB, Johnson DG, Gulakowski R, Cardellina JHI and Boyd MR: Cycloviolins A-D, anti-HIV macrocyclic peptides from Leonia cymosa.\u00a0J. Org. Chem.<\/em>(2000) 65:124-128.<\/p>\nHernandez JF, Gagnon J, Chiche L, Nguyen TM, Andrieu JP, Heitz A, Trinh Hong T, Pham TT and Le Nguyen D: Squash trypsin inhibitors from Momordica cochinchinensis exhibit an atypical macrocyclic structure.\u00a0Biochemistry<\/em>\u00a0(2000) 39:5722-5730.<\/p>\nSaether O, Craik DJ, Campbell ID, Sletten K, Juul J and Norman DG: Elucidation of the primary and three-dimensional structure of the uterotonic polypeptide kalata B1.\u00a0Biochemistry<\/em>\u00a0(1995) 34:4147-4158.<\/p>\nSch\ufffdpke T, Hasan Agha MI, Kraft R, Otto A and Hiller K: H\ufffdmolytisch aktive komponenten aus Viola tricolor L. und Viola arvensis Murray.\u00a0Sci. Pharm.<\/em>\u00a0(1993) 61:145-153.<\/p>\nWitherup KM, Bogusky MJ, Anderson PS, Ramjit H, Ransom RW, Wood T and Sardana M: Cyclopsychotride A, A biologically active, 31-residue cyclic peptide isolated from Psychotria Longipes.\u00a0J. Nat. Prod.<\/em>\u00a0(1994) 57:1619-1625.<\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"African medicine-cyclotides as an aid during child\u00a0birth Oldenlandia affinis\u00a0was used by native women in the Zaire as an aid during childbirth. A tea was made of the leaves and imbibed during labour. Cyclotides are plant-derived peptides of approximately 30 amino acids. They have the characteristic structural features of a head-to-tail cyclized backbone and a… Continue reading African medicine-cyclotides as an aid during child birth<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[33],"tags":[128,129,130,69],"_links":{"self":[{"href":"https:\/\/amcrasto.theeurekamoments.com\/wp-json\/wp\/v2\/posts\/1259"}],"collection":[{"href":"https:\/\/amcrasto.theeurekamoments.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/amcrasto.theeurekamoments.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/amcrasto.theeurekamoments.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/amcrasto.theeurekamoments.com\/wp-json\/wp\/v2\/comments?post=1259"}],"version-history":[{"count":1,"href":"https:\/\/amcrasto.theeurekamoments.com\/wp-json\/wp\/v2\/posts\/1259\/revisions"}],"predecessor-version":[{"id":1260,"href":"https:\/\/amcrasto.theeurekamoments.com\/wp-json\/wp\/v2\/posts\/1259\/revisions\/1260"}],"wp:attachment":[{"href":"https:\/\/amcrasto.theeurekamoments.com\/wp-json\/wp\/v2\/media?parent=1259"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/amcrasto.theeurekamoments.com\/wp-json\/wp\/v2\/categories?post=1259"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/amcrasto.theeurekamoments.com\/wp-json\/wp\/v2\/tags?post=1259"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}