Cyclotides are peptides. Medical search. Frequent questions

Compounds of interest include not only classical "drug-like" organic small molecules, but also peptides, proteins, and other bioactive chemical classes. (cancer.gov)
Peptides, like proteins, are polymers composed of amino acids, the basic building blocks of living organisms. (botany.pl)
The difference lies in the length of the chain - peptides are much smaller than proteins. (botany.pl)
Chances are that a assortment of brand-new ligands will emerge because high-throughput assays have already been developed to display screen for peptides that bind selectively to different conformations of G proteins subunits [50] or focus on the user interface with a particular subset of RGS protein [51]. (biotechpatents.org)
Because of high production price, peptide or proteins availability Batimastat sodium salt could be augmented through polymer conjugation (such as for example was showed by PEGylation of RANTES analogue),55 or by better medication delivery strategies. (nsdfu.org)
Further promising properties of this peptide inhibitor include improved serum stability relative to linear and simple cyclic analogues, and a lower affinity for serum proteins that would likely be responsible for opsonization and clearance prior to reaching their targets. (nsdfu.org)
Asparaginyl endopeptidases (AEPs) are versatile enzymes that in biological systems are involved in producing three different catalytic outcomes for proteins, namely (i) routine cleavage by bond hydrolysis, (ii) peptide maturation, including macrocyclisation by a cleavage-coupled intramolecular transpeptidation and (iii) circular permutation involving separate cleavage and transpeptidation reactions resulting in a major reshuffling of protein sequence. (silverchair.com)

In particular, plant cyclotides, disulfide-rich peptides comprising three conserved disulfide bonds in a knotted arrangement, known as cyclic cystine knot motif, and a head-to-tail cyclization, have been extensively investigated over the last four decades for their use as scaffolds in drug development. (biomedcentral.com)

Exploring the Sequence Diversity of Cyclotides from Vietnamese Viola Species. (cipps.org.au)

Several macrocyclic peptides ( approximately 30 amino acids), with diverse biological activities, have been isolated from the Rubiaceae and Violaceae plant families over recent years. (rcsb.org)
The biological activity of a cyclotide depends on its amino acid sequence and structure of the molecule, e.g. kalata B1 acts against insect larvae and cycloviolacin O2 is antimicrobial. (botany.pl)
His research integrates issues of Cyclic peptide, Biological activity, Pharmacognosy and Sponge in his study of Stereochemistry. (research.com)
Cyclotides display a diverse range of biological activities, including uterotonic activity, inhibition of neurotensin binding, hemolytic, anti-HIV and anti-microbial activity. (bicnirrh.res.in)
Biochemical, biophysical and biological assays using isolated amyloid β peptide, primary neurons and various established Alzheimer's disease nematode models showed that the selected macrocycles potently inhibit the formation of neurotoxic amyloid β peptide aggregates. (nature.com)
Recently, two novel biological active peptides, hedyotide B1 and B2 (hedyotide = hedyotis + peptide), have been isolated from the ariel parts of the medicinal plant Hedyotis biflora. (ranchimunicipal.com)

Cyclotides (cyclo peptides) are plant peptides of ~30 amino acids with a head to-tail cyclic backbone and six cysteine residues involved in three disulphide bonds. (bicnirrh.res.in)
We demonstrate the effectiveness of this approach by identifying drug-like, head-to-tail cyclic peptides that modulate the aggregation of the Alzheimer's disease-associated amyloid β peptide. (nature.com)

Research assistant position to finish lab work for last ongoing project (delivery of cyclotides targeting p53 in the cytosol of cancer cells. (u-tokyo.ac.jp)
Targeted Delivery of Cyclotides via Conjugation to a Nanobody" ACS Chem. (bmrb.io)

β-sheet breaker peptides inhibit fibrillogenesis in a rat brain model of amyloidosis: implications for Alzheimer's therapy. (nature.com)
Researchers explain why this discovery is important to MS- ' cyclotides, in particular [T20K]kB1, inhibit T-cell proliferation by down-regulation of IL-2 release as well as IL-2R/CD25 surface expression (13). (activemsers.org)

Values of minimal inhibitory concentration (MIC) varv peptide B[del8] on different Gram-negative bacterial fish pathogens. (cybase.org.au)

Cyclotides are peptides produced in plants, characterized by a cyclic peptide backbone where both ends of the amino acid chain meet. (botany.pl)
The full article : Oral activity of a nature-derived cyclic peptide for the treatment of multiple sclerosis. (activemsers.org)

CAMPSign is a tool for identification of antimicrobial peptides belonging to one of the 45 major AMP families present in CAMP R3 . (bicnirrh.res.in)
Abaecin represents antimicrobial peptides produced by bees. (bicnirrh.res.in)
This family of peptide exhibit no structural similarity with other antimicrobial peptides from frogs skin [PMID: 15207717]. (bicnirrh.res.in)
Bacteriocins are ribosomally synthesized antimicrobial peptides produced by diverse bacteria. (bicnirrh.res.in)
Brevinins are antimicrobial peptides obtained from the skin secretions of frogs [PMID: 22307792]. (bicnirrh.res.in)
The precursor sequences of a number of antimicrobial peptides secreted by neutrophils (polymorphonuclear leukocytes) upon activation have been found to be evolutionarily related and are collectively known as cathelicidins [PMID: 7589491]. (bicnirrh.res.in)
The family is made up of four alpha-helical antimicrobial peptides, clavanins A, B, C and D. The tunicate peptides resemble magainins in size, primary sequence and antibacterial activity. (bicnirrh.res.in)
The presence of alpha-helical antimicrobial peptides in the haemocytes of a urochordate suggests that such peptides are primeval effectors of innate immunity in the vertebrate lineage [PMID: 9001389]. (bicnirrh.res.in)
Cupiennins are a family of antimicrobial peptides isolated from the venom of Cupiennius salei. (bicnirrh.res.in)

We refer to these peptides as the cyclotide family and their embedded topology as the cyclic cystine knot (CCK) motif. (rcsb.org)
However, examples of rotaxane substructure have been found in naturally occurring peptides, including: cystine knot peptides, cyclotides or lasso-peptides such as microcin J25. (rf-onlinegame.com)

Jackson, Wyoming-January 26, 2022) - A circular peptide derived from violets could lead to new approaches in treating glioblastoma, a highly aggressive form of brain cancer. (clinicalnews.org)

One of the conserved hydrophobic interface residues, Tyr10 was mutated to Ala and the impact of this virtual mutation was estimated by additional MD simulations for the wild-type (WT) and mutant protein-peptide complexes. (ncbs.res.in)
The φ-ѱ distribution map of residues in the cyclotide binding pocket that ideally adopt β-sheet conformation show deviation towards right-handed ɑ-helical (ɑ) conformation. (ncbs.res.in)
The T140 peptide, a peptide derived from polyphemusin II, was one of the first X4 inhibitors reported by Fujii and coworkers in 2000, and has served as a scaffold for CXCR4 inhibitor development.68 Shortly thereafter, the Fujii group identified the pharmacophore associated with T140, a linear four amino acid sequence that includes several basic residues and the nonnatural amino acid naphthylalanine (Figure 2). (nsdfu.org)
Testosterone and six months of high dose effects morris C: Fulvestrant, formerly ICI 182,780, is as effective with peptides of up to 50 randomly assembled amino acid residues. (wahoowebsite.com)

This structure is similar to kalata B1 and circulin A, the only two macrocyclic peptides for which a structure was available, suggesting that despite the sequence variation throughout the peptides they form a family in which the overall fold is conserved. (rcsb.org)
In conclusion, our results underpin earlier suggestions that cyclotides are one of the largest peptide classes within plants, covering a large chemical space based on their high sequence diversity. (biomedcentral.com)
We optimized the cyclotide screening protocol using MALDI-TOF/TOF and two dimensional nano LC-MS/MS followed by manual and automated peptide sequence assignments. (biomedcentral.com)
Cyclotides are interesting targets for pharmaceutical applications due to their unique structural framework, their bioactivities and sequence diversity. (biomedcentral.com)

We have significantly expanded the range of known macrocyclic peptides with the discovery of 16 novel peptides from extracts of Viola hederaceae, Viola odorata and Oldenlandia affinis. (rcsb.org)
The Viola plants had not previously been examined for these peptides and thus represent novel species in which these unusual macrocyclic peptides are produced. (rcsb.org)
How does sweet violet ( Viola odorata L.) fight pathogens and pests - are cyclotides a type of plant immune system? (botany.pl)

The resultant peptide showed improved activity over the previously reported cyclic CVX15 peptide Batimastat sodium salt in HIV inhibition assays, exhibiting EC50 values of ~2 nM. (nsdfu.org)

The screening of linear peptide analogues, originally designed from natural orbitides isolated from Jatropha species, demonstrated that some molecules (linear pohlianin B and linear ribifolin) have the potential to induce fibroblast migration and collagen deposition and may thus contribute to accelerating the processes of wound healing and tissue repair. (scielo.org)
However, their distribution among flowering plants still remains limited to few species of the families of Rubiaceae (coffee), Violaceae (violet), Cucurbitaceae (cucurbit), Fabaceae (bean) and recently Solanaceae (potato family), but it is very likely that cyclotides are more widely distributed since their predicted number in Rubiaceae alone is ~50.000. (biomedcentral.com)
Using a MALDI-TOF/TOF-based screening protocol we were able to identify many novel cyclotide-containing species which was confirmed by manual de novo sequencing and automated database identification. (biomedcentral.com)
300 flowering plant species and confirmed the presence of cyclotides in several plant families. (biomedcentral.com)
Bombinins are animicrobial peptides obtained from the skin secretion of Bombina species. (bicnirrh.res.in)

This sheds light on the future of cyclotide-based drug design against protein aggregation, a hallmark event in many neurodegenerative diseases. (ncbs.res.in)
at the same time developing protein and peptide-based tools that will allow us to manipulate cellular processes on a molecular level. (stanford.edu)
This proposal presents an innovative approach for screening and selecting a new class of highly stable protein capture reagents and developing a new versatile approach for ligand immobilization that together enable rapid production of cyclotide-based microarrays for proteomics research. (nih.gov)
During this time, he has developed HPLC-mass spectrometry interfaces, methods of analysis for natural products, drug and pesticide analysis, peptide and protein analysis. (edu.au)
Desk 2 G Protein-Coupled Receptors for Protein and Peptides molecular modeling. (biotechpatents.org)
A straight richer way to obtain recognition motifs are available at the supplementary structure level, especially considering that details content in protein/peptides is normally evolutionary even more conserved through threedimensional buildings instead of through linear amino acidity sequences [55]. (biotechpatents.org)
Thus, development of macromolecular antagonists centred on peptide fragments derived from components that were able to interact selectively with the receptor, including SDF1-, gp120, and the viral macrophage inflammatory protein-II (vMIP-II).67 Early work in this field has been reviewed elsewhere, 61 and the remainder of the discussion will focus on peptide and protein inhibitors discovered since 2008. (nsdfu.org)
Based on their predicted number of tens of thousands, which potentially makes them one of the largest protein families within the plant kingdom, they constitute an immense combinatorial library of natural peptides, which is accessible for drug discovery. (biomedcentral.com)
Postdoctoral researcher at the Queensland university of technology working with Sónia Henriques for the Centre of excellence for Innovations in Peptide and Protein Science. (u-tokyo.ac.jp)

To date, in the cyclotide field, much effort has been put into applicable research, e.g. to use the structure of these peptides as a scaffold to design new drugs. (botany.pl)
Comparable scaffolds have already been utilized to template high-affinity peptides for the medicinally relevant integrin receptors.65,66 In this example, researchers adapted a known inhibitor of CXCR4, for which structural information had been recently determined, and grafted it in various positions within a cyclotide scaffold derived from the horseshoe crab peptides polyphemusin I/II. (nsdfu.org)

Combinatorial and organic peptide libraries are consequently more likely to play a significant role in determining fresh GPCR ligands at each one of these sites. (biotechpatents.org)

Our current findings provide novel structural insights on the mode of interaction between cyclotides and Aβ fibrils and describe their anti-amyloid aggregation potential. (ncbs.res.in)
Here we define 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. (rcsb.org)
Orbitides are a class of small naturally occurring cyclic peptides with structural and functional diversities. (scielo.org)
The growing body of knowledge regarding CXCR4 and its interactions with inhibitors has enabled the generation of novel structural motifs in both peptides and peptidomimetics with improved antiviral activities. (nsdfu.org)
Cyclotides are disulfide-rich miniproteins with the unique structural features of a circular backbone and knotted arrangement of three conserved disulfide bonds. (biomedcentral.com)

Based on the traditional usage of the plant Oldenlandia affinis as an uterotonic agent, we have tested and identified cyclotides with oxytocin-like activity and identified the oxytocin receptor, as representative member of the GPCR family, as a molecular target of cyclotides. (biomedcentral.com)

The T20K peptides exhibit extraordinary stability and chemical features that are ideally what you want in an oral drug candidate. (buzzpost.com)

Further, we have determined the three-dimensional structure of one of these novel peptides, cycloviolacin O1, using (1)H NMR spectroscopy. (rcsb.org)

In this project we will determine the ability of these peptides to modulate immunity in insects, allowing (i) elucidating their role in herbivore defense as well as (ii) utilizing the insect model system to guide translational approaches to study immunomodulatory mechanisms of these peptides as treatment for autoimmune diseases. (edu.au)

Effects of a plant cyclotide on conformational dynamics and destabilization of β-amyloid fibrils through molecular dynamics simulations. (ncbs.res.in)
In the present study, through extensive computational docking and multi-ns molecular dynamics (MD) simulation, we evaluated if cyclotides can stably bind to Aβ molecules and/or destabilize the Aβ fibril by preventing conformational changes from α-helical to β-sheet rich structures. (ncbs.res.in)
Several convert buildings are located to become stabilized by cyclic loop and band moieties, in particular regarding smaller and even more flexible peptides that want conformational stabilization to keep a rigid threedimensional framework. (biotechpatents.org)

Based on the use of plants in traditional Nigerian medicine during pregnancy and childbirth, we analyzed several plants from different families to evaluate their uterotonic properties at cellular level and to identify cyclotides as active molecules. (biomedcentral.com)
The evaluation of contractile properties of plants used in traditional medicines offers new starting points for the discovery and development of peptide-based uterotonic drug leads. (biomedcentral.com)

The second subfamily contains a backbone twist due to a cis-Pro peptide bond and may conceptually be regarded as a molecular Moebius strip. (rcsb.org)

Cyclotides are stored in the vacuoles and it is poorly understood how molecules can be excreted from this cell compartment once they are deposited there. (botany.pl)
The important question about cyclotides as defense molecules arises: how can they be excreted from the vacuole in response to infection? (botany.pl)

Peptide antibiotic AS-48 exerts a bactericidal mode of action on exponential cultures of Escherichia coli K-12 through a multi-hit kinetics interaction. (cybase.org.au)
The caerin 1 peptides are among the most powerful of the broad-spectrum antibiotic amphibian peptides [PMID: 12717721]. (bicnirrh.res.in)
A strongly basic peptide, antibiotic complex from several strains of Streptomyces. (nih.gov)

We previously isolated widely distributed circular plant peptides (called cyclotides) that suppress immune cell proliferation in human cells. (edu.au)
Circular plant peptides as templates for GPCR drug discovery? (biomedcentral.com)
On the basis of the phylogeny of cyclotide-bearing plants and the analysis of precursor gene sequences, we have refined the current hypothesis of the evolution of circular plant peptides. (biomedcentral.com)

Specifically the diverse organic peptide libraries like the venom peptides from sea cone-snails and vegetable cyclotides have already been established like a rich way to obtain medication leads. (biotechpatents.org)

Dr Gruber said the new treatment arose from a synthesised plant peptide, a class of drugs known as cyclotides. (buzzpost.com)
Development of peptide-based anticancer drugs targeting the p53 pathway. (u-tokyo.ac.jp)

Aggregation of β-amyloid (Aβ) peptide is one of the hallmarks of Alzheimer's disease (AD) which results in chronic and progressive neurodegeneration of the brain. (ncbs.res.in)
A detailed MD simulation analyses revealed that cyclotides form hydrogen bonds with the toxic amyloid assemblies thereby weakening the inter-strand hydrogen bonds between the Aβ peptide. (ncbs.res.in)
It is therefore possible to hypothesise that the opening up of amyloid β-sheet is due to an unfolding process occurring in the Aβ caused by cyclotide binding and inhibition. (ncbs.res.in)

We aim to prove the hypothesis that cyclotides from the Violaceae are a type of plant immune system where biosynthesis and accumulation of these peptides is regulated in response to the environment. (botany.pl)

The aqueous extracts and semipure peptide fractions have been tested further in a collagen gel contractility assay model and showed varying ability to induce contractions in human myometrial smooth muscle cells. (biomedcentral.com)

The second objective is to understand the mechanisms responsible for delivering cyclotides to the extracellular spaces in the course of the antimicrobial defense process. (botany.pl)

We demonstrate that cyclotides bind effectively and stably to different forms of Aβ structures hydrogen bonding and hydrophobic interactions. (ncbs.res.in)

A pancreastatin (PST) variant peptide, PSTv1, competes with endogenous PST to produce anti-diabetic effects. (iitm.ac.in)

Therefore, this synthetic accessibility enables useful application and facilitates the identification of analogues, bioactivity studies, and thus, enables them to be applied to obtain peptide libraries. (scielo.org)

To date, cyclotides have been found in six non-related families of plants including the Violaceae. (botany.pl)
Cyclotides are present in a range of common plants, and they show significant potential for the treatment of auto immune diseases," he said. (buzzpost.com)
Butterfly pea is one of the few plants on earth that contain cyclotides, peptides that have shown to possess anti-HIV and anti-tumor properties, while certain cyclotides have been shown to be toxic to cancer cells. (kingdomwellnessteas.com)

are cyclotides a type of plant immune system? (botany.pl)
Combining immunohistochemistry and cutting-edge techniques of mass spectrometry, MALDI imaging, and transcriptomics we will be able to gain deep understanding of cyclotide phenomenon as a type of plant immune system and answer a question if the response in the biosynthesis of particular sets of these peptides is specific to stimuli. (botany.pl)

This will become illustrated by concentrating on the ligand-based medication style of oxytocin (OT) and vasopressin (AVP) receptor ligands using organic peptide qualified prospects as starting factors. (biotechpatents.org)

These peptides exhibit broad spectrum antimicrobial activity against Bacteria as well as fungi. (bicnirrh.res.in)

Taken together, these data indicate that cyclotide scaffolds are promising macromolecular architectures for the discovery of `drug-gable' receptor-specific antagonists. (nsdfu.org)
The discovery of butelase-1, an extremely efficient AEP (catalytic efficiency of up to 1 340 000 M −1 s −1 on a non-native substrate) [ 6 , 7 ] that forms peptide bonds via a cleavage-coupled transpeptidation reaction, has led to a surge of interest in AEPs. (silverchair.com)

Their chemical properties make this class feasible to be obtained by solid phase peptide synthesis (SPPS). (scielo.org)

Ascaphin family of antibacterial peptides are secreted from the frog Ascaphus truei. (bicnirrh.res.in)
This family of antibacterial peptides are secreted from the granular dorsal glands of Litoria aurea (Green and golden bell frog), Litoria raniformis (Southern bell frog), Litoria citropa (Australian blue mountains tree frog) and frogs from genus Uperoleia. (bicnirrh.res.in)
They are a part of the FSAP peptide family. (bicnirrh.res.in)
Cecropin P1, an intestinal antibacterial peptide from Sus scrofa (Pig), also belongs to this family. (bicnirrh.res.in)

Nanotubes, Peptide" is a descriptor in the National Library of Medicine's controlled vocabulary thesaurus, MeSH (Medical Subject Headings) . (uams.edu)

Organisms7

Diseases1

Chemicals and Drugs5

Phenomena and Processes3

Technology, Industry, Agriculture1

Information Science2

Proteins7

Disulfide-rich peptides1

Diversity of Cyclotides1

Biological6

Head to-tail cyclic2

Delivery of cyclotides2

Inhibit2

Varv peptide1

Cyclic peptide2

Antimicrobial peptides9

Cystine2

20221

Residues4

Sequence4

Viola3

Assays1

Species5

Protein9

Scaffold2

Combinatorial1

Structural5

Oldenlandia1

T20K1

Cycloviolacin1

Modulate1

Conformational3

Uterotonic2

Molecular1

Molecules2

Antibiotic3

Circular3

Venom1

Drugs2

Amyloid3

Hypothesis1

Extracts1

Defense1

Structures1

Endogenous1

Libraries1

Plants3

Immune2

Oxytocin1

Exhibit1

Discovery2

Class1

Family4

MeSH1