Topic
Cyclotides
About: Cyclotides is a research topic. Over the lifetime, 403 publications have been published within this topic receiving 19572 citations.
Papers published on a yearly basis
Papers
TL;DR: Using frequently occurring residues, database-aided peptide design in different ways is demonstrated, and GLK-19 showed a higher activity against Escherichia coli than human LL-37 and Leu, Ala, Gly and Lys in amphibian peptides.
Abstract: The antimicrobial peptide database (APD, http://aps.unmc.edu/AP/main.php) has been updated and expanded. It now hosts 1228 entries with 65 anticancer, 76 antiviral (53 anti-HIV), 327 antifungal and 944 antibacterial peptides. The second version of our database (APD2) allows users to search peptide families (e.g. bacteriocins, cyclotides, or defensins), peptide sources (e.g. fish, frogs or chicken), post-translationally modified peptides (e.g. amidation, oxidation, lipidation, glycosylation or d-amino acids), and peptide binding targets (e.g. membranes, proteins, DNA/RNA, LPS or sugars). Statistical analyses reveal that the frequently used amino acid residues (>10%) are Ala and Gly in bacterial peptides, Cys and Gly in plant peptides, Ala, Gly and Lys in insect peptides, and Leu, Ala, Gly and Lys in amphibian peptides. Using frequently occurring residues, we demonstrate database-aided peptide design in different ways. Among the three peptides designed, GLK-19 showed a higher activity against Escherichia coli than human LL-37.
985 citations
TL;DR: The structural features of the two apparent subfamilies of the CCK peptides which may be significant for the likely defense related role of these peptides within plants are defined.
800 citations
TL;DR: The stability of the prototypic cyclotide kalata B1 to the chaotropic agents 6 M guanidine hydrochloride and 8 M urea is demonstrated to temperatures approaching boiling, to acid, and following incubation with a range of proteases, conditions under which most proteins readily unfold.
Abstract: The cyclotides constitute a recently discovered family of plant-derived peptides that have the unusual features of a head-to-tail cyclized backbone and a cystine knot core. These features are thought to contribute to their exceptional stability, as qualitatively observed during experiments aimed at sequencing and characterizing early members of the family. However, to date there has been no quantitative study of the thermal, chemical, or enzymatic stability of the cyclotides. In this study, we demonstrate the stability of the prototypic cyclotide kalata B1 to the chaotropic agents 6 M guanidine hydrochloride (GdHCl) and 8 M urea, to temperatures approaching boiling, to acid, and following incubation with a range of proteases, conditions under which most proteins readily unfold. NMR spectroscopy was used to demonstrate the thermal stability, while fluorescence and circular dichroism were used to monitor the chemical stability. Several variants of kalata B1 were also examined, including kalata B2, which has...
566 citations
TL;DR: A potent inhibitory effect on the growth and development of larvae from the Lepidopteran species Helicoverpa punctigera is described, indicating that the cyclotide domains are excised and cyclized from all four predicted precursor proteins.
Abstract: Several members of the Rubiaceae and Violaceae families produce a series of cyclotides or macrocyclic peptides of 29–31 amino acids with an embedded cystine knot. We aim to understand the mechanism of synthesis of cyclic peptides in plants and have isolated a cDNA clone that encodes the cyclotide kalata B1 as well as three other clones for related cyclotides from the African plant Oldenlandia affinis. The cDNA clones encode prepropeptides with a 20-aa signal sequence, an N-terminal prosequence of 46–68 amino acids and one, two, or three cyclotide domains separated by regions of about 25 aa. The corresponding cyclotides have been isolated from plant material, indicating that the cyclotide domains are excised and cyclized from all four predicted precursor proteins. The exact processing site is likely to lie on the N-terminal side of the strongly conserved GlyLeuPro or SerLeuPro sequence that flanks both sides of the cyclotide domain. Cyclotides have previously been assigned an antimicrobial function; here we describe a potent inhibitory effect on the growth and development of larvae from the Lepidopteran species Helicoverpa punctigera.
504 citations
TL;DR: The stability of peptide toxins containing the cystine knot motif, their range of bioactivities and their unique structural scaffold can be harnessed for molecular engineering applications and in drug design.
457 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 16 |
| 2020 | 20 |
| 2019 | 16 |
| 2018 | 14 |
| 2017 | 25 |
| 2016 | 20 |