Norelle L Daly

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Several macrocyclic peptides ( approximately 30 amino acids), with diverse biological activities, have been isolated from the Rubiaceae and Violaceae plant families over recent years. 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(More)
The cystine knot structural motif is present in peptides and proteins from a variety of species, including fungi, plants, marine molluscs, insects and spiders. It comprises an embedded ring formed by two disulfide bonds and their connecting backbone segments which is threaded by a third disulfide bond. It is invariably associated with nearby beta-sheet(More)
The O-conotoxins are an intriguing class of conotoxins targeting various voltage-dependent sodium channels and molluscan calcium channels. In the current study, we have shown MrVIA and MrVIB to be the first known peptidic inhibitors of the transient tetrodotoxinresistant (TTX-R) Na current in rat dorsal root ganglion neurons, in addition to inhibiting(More)
In recent years an increasing number of miniproteins containing an amide-cyclized backbone have been discovered. The cyclotide family is the largest group of such proteins and is characterized by a circular protein backbone and six conserved cysteine residues linked by disulfide bonds in a tight core of the molecule. These form a cystine knot in which an(More)
Kalata B1 is a member of a new family of polypeptides, isolated from plants, which have a cystine knot structure embedded within an amide-cyclized backbone. This family of molecules are the largest known cyclic peptides, and thus, the mechanism of synthesis and folding is of great interest. To provide information about both these phenomena, we have(More)
Much interest has been generated by recent reports on the discovery of circular (i.e. head-to-tail cyclized) proteins in plants. Here we report the three-dimensional structure of one of the newest such circular proteins, MCoTI-II, a novel trypsin inhibitor from Momordica cochinchinensis, a member of the Cucurbitaceae plant family. The structure consists of(More)
A large number of macrocyclic miniproteins with diverse biological activities have been isolated from the Rubiaceae, Violaceae, and Cucurbitaceae plant families in recent years. Here we report the three-dimensional structure determined using (1)H NMR spectroscopy and demonstrate potent insecticidal activity for one of these peptides, kalata B2. This peptide(More)
Using assay-directed fractionation of Conus geographus crude venom, we isolated alpha-conotoxin GID, which acts selectively at neuronal nicotinic acetylcholine receptors (nAChRs). Unlike other neuronally selective alpha-conotoxins, alpha-GID has a four amino acid N-terminal tail, gamma-carboxyglutamate (Gla), and hydroxyproline (O) residues, and lacks an(More)
The cyclic peptide sunflower trypsin inhibitor 1 (SFTI-1) blocks trypsin and is a promising drug lead and protein engineering scaffold. We show that SFTI-1 and the newfound SFT-L1 are buried within PawS1 and PawS2, precursors for seed storage protein albumins. Proalbumins are matured by asparaginyl endopeptidase, which we show is required to liberate both(More)
The three-dimensional solution structure of circulin A, a 30 residue polypeptide from the African plant Chassalia parvifolia, has been determined using two-dimensional 1H-NMR spectroscopy. Circulin A was originally identified based upon its inhibition of the cytopathic effects and replication of the human immunodeficiency virus. Structural restraints(More)