Anti-HIV Cyclotides

Gustafson, Kirk R.; McKee, Tawnya C.; Bokesch, Heidi R.

doi:10.2174/1389203043379468

Cited by 150 publications

(135 citation statements)

References 1 publication

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“…The plant has a strong folk reputation in the treatment of cancer. Viola has been investigated for cytotoxicity and reported as a pharmacological tool serving as antitumor agents (Lindholm et al 2002;Mokhtari 2016;Gustafson 2004;Ireland et al 2006;Ebrahimzadeh et al 2010). …”

Section: Introductionmentioning

confidence: 99%

Interactive effects of plant growth regulators and explants on direct shoot regeneration of Viola odorata

Mokhtari¹,

Zarei²,

Samsamzadeh³

et al. 2016

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The aim of the study was to develop a protocol for in vitro shoot regeneration based on a solid Murashige and Skoog (MS) basal medium supplemented with various concentrations of plant growth regulators (PGRs) like Indole-3-butyric acid (IBA), kinetin (KIN) or benzylaminopurine (BAP) using leaf, petiole, root, and crown disk segments of a valuable medicinal plant Viola odorata. The best percentage of direct shoot regeneration (67.50%) and the maximum number of micro-shoots (9.50) were obtained with crown explants on MS medium containing IBA (0.5 mg A l ). The best elongation (5.25 cm) of micro-shoots was observed in crown explants on a medium containing 1 mg A l !1 gibberellic acid (GA3) followed by GA3 at 0.5 mg A l !1 and similar explants. Irrespective of the concentrations of GA3, the minimum length of shoots was observed in leaf explants. A half-strength MS medium containing activated charcoal and supplemented with 1.5 mg A l !1 IBA resulted in the best rooting (78%) of elongated shoots. All acclimatized plantlets survived and showed a normal growth.The study reports a simple and applicable protocol for micropropagation of V. odorata through direct organogenesis.

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Section: Introductionmentioning

confidence: 99%

Interactive effects of plant growth regulators and explants on direct shoot regeneration of Viola odorata

Mokhtari¹,

Zarei²,

Samsamzadeh³

et al. 2016

bta

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“…Cyclotides 1,2 are a unique class of head-to-tail cyclic cysteine-15 rich microproteins up to 37 amino acids in length that exhibit a wide range of biological properties, ranging from anti-HIV [3][4][5] to insecticidal activity. 6,7 In contrast to many smaller naturally occurring cyclic peptides they are true gene products, and possess a highly stable cystine-knot † topology, 20 whereby two disulfide bridges form a ring through which a third is threaded.…”

Section: Introductionmentioning

confidence: 99%

Chemical and biomimetic total syntheses of natural and engineered MCoTI cyclotides

et al. 2008

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The naturally-occurring cyclic cystine-knot microprotein trypsin inhibitors MCoTI-I and MCoTI-II have been synthesised using both thia-zip native chemical ligation and a biomimetic strategy featuring chemoenzymatic cyclisation by an immobilised protease. Engineered analogues have been produced containing a range of substitutions at the P 1 position that redirect specificity 10 towards alternative protease targets whilst retaining excellent to moderate affinity. Furthermore, we report an MCoTI analogue that is a selective low-µM inhibitor of foot-and-mouth-disease virus (FMDV) 3C protease, the first reported inhibitor of this important viral enzyme.

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“…The cyclotides are a distinctive class of plant defense peptides produced by various species in the Violaceae and Rubiaceae Craik, 2001;Gustafson et al, 2004;. They are characterized by their head-to-tail cyclization and cystine knot motif , which contribute to their exceptional resistance to physical, chemical, and biochemical degradation (Gran, 1973a;Colgrave and Craik, 2004).…”

Section: Introductionmentioning

confidence: 99%

A Continent of Plant Defense Peptide Diversity: Cyclotides in AustralianHybanthus(Violaceae)

et al. 2005

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Cyclotides are plant-derived miniproteins that have the unusual features of a head-to-tail cyclized peptide backbone and a knotted arrangement of disulfide bonds. It had been postulated that they might be an especially large family of host defense agents, but this had not yet been tested by field data on cyclotide variation in wild plant populations. In this study, we sampled Australian Hybanthus (Violaceae) to gain an insight into the level of variation within populations, within species, and between species. A wealth of cyclotide diversity was discovered: at least 246 new cyclotides are present in the 11 species sampled, and 26 novel sequences were characterized. A new approach to the discovery of cyclotide sequences was developed based on the identification of a conserved sequence within a signal sequence in cyclotide precursors. The number of cyclotides in the Violaceae is now estimated to be >9000. Cyclotide physicochemical profiles were shown to be a useful taxonomic feature that reflected species and their morphological relationships. The novel sequences provided substantial insight into the tolerance of the cystine knot framework in cyclotides to amino acid substitutions and will facilitate protein engineering applications of this framework.

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Anti-HIV Cyclotides

Cited by 150 publications

References 1 publication

Interactive effects of plant growth regulators and explants on direct shoot regeneration of Viola odorata

Interactive effects of plant growth regulators and explants on direct shoot regeneration of Viola odorata

Chemical and biomimetic total syntheses of natural and engineered MCoTI cyclotides

A Continent of Plant Defense Peptide Diversity: Cyclotides in AustralianHybanthus(Violaceae)

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