Publications by authors named "Tara Pukala"

Small differences in the structure and subsequent reactivity of glyphosate complexes can have a highly consequential impact due to the enormous quantities of glyphosate used globally. The gas phase metal speciation of glyphosate and its abundant metabolite, aminomethylphosphonic acid (AMPA), were determined using cross-platform electrospray ionisation ion mobility mass spectrometry. Monomeric [M + L - H] complexes, and both larger, and/or higher order clusters formed with divalent metals (M = Mg, Ca, Sr, Ba, Mn, Co, Cu, and Zn; and L = glyphosate and AMPA).

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Snake venoms are comprised of bioactive proteins and peptides that facilitate severe snakebite envenomation symptoms. A comprehensive understanding of venom compositions and the subtle heterogeneity therein is important. While bottom-up proteomics has been the well-established approach to catalogue venom compositions, top-down proteomics has emerged as a complementary strategy to characterize venom heterogeneity at the intact protein level.

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The use of direct injection ion mobility mass spectrometry (DI-IM-MS) to detect and identify betacyanin pigments in A. hortensis 'rubra' extracts was explored for the first time, with results compared to conventional LC-MS/MS analysis. The anti-inflammatory activities of leaf and seed extracts, alongside purified amaranthin and celosianin pigments, were investigated using a model of lipopolysaccharide (LPS)-activated murine macrophages.

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Deoxyribonucleic acid triplexes have potential roles in a range of biological processes involving gene and transcriptional regulation. A major challenge in exploiting the formation of these higher-order structures to target genes is their low stability, which is dependent on many factors including the length and composition of bases in the sequence. Here, different DNA base modifications have been explored, primarily using native mass spectrometry, in efforts to enable stronger binding between the triplex forming oligonucleotide (TFO) and duplex target sites.

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Snakebite envenomation has been a long-standing global issue that is difficult to treat, largely owing to the flawed nature of current immunoglobulin-based antivenom therapy and the complexity of snake venoms as sophisticated mixtures of bioactive proteins and peptides. Comprehensive characterisation of venom compositions is essential to better understanding snake venom toxicity and inform effective and rationally designed antivenoms. Additionally, a greater understanding of snake venom composition will likely unearth novel biologically active proteins and peptides that have promising therapeutic or biotechnological applications.

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Red-fleshed apple cultivars with an enhanced content of polyphenolic compounds have attracted increasing interest due to their promising health benefits. Here, we have analysed the polyphenolic content of young, red-fleshed apples (RFA) and optimised extraction conditions of phenolics by utilising natural deep eutectic solvents (NDES). We also compare the antioxidant, neuroprotective and antimicrobial activities of NDES- and methanol-extracted phenolics from young RFA.

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Deoxyribonucleic acid is a genetic biomacromolecule that contains the inherited information required to build and maintain a living organism. While the canonical duplex DNA structure is rigorously characterized, the structure and function of higher order DNA structures such as DNA triplexes are comparatively poorly understood. Previous literature has shown that these triplexes can form under physiological conditions, and native mass spectrometry offers a useful platform to study their formation and stability.

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Article Synopsis
  • - The study investigates the venom composition of a highly lethal snake, which is classified as a category one snake by the WHO, focusing on its main components and their potential impacts on mortality and disability.
  • - Using size exclusion chromatography and bottom-up proteomics, researchers found that neurotoxins, particularly three-finger toxins (3FTx), comprise 76.01% of the venom, along with other toxins like phospholipase A2s and snake venom metalloproteinases.
  • - Notably, the study highlights the previously unreported presence of phospholipase A2 toxins and the first evidence of covalent protein complexes in the venom, suggesting significant variations within species that may affect venom potency.
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Bat pollination of in Fiji, a genus that was presumed to be pollinated by bees, posits that other species may be bat-pollinated, with implications for conservation and the understanding of angiosperm evolution. Botanical descriptions of some corolla behaviours ('falling as a whole') suggest bat removal of permanently closed corollas, as in . Considering the remoteness of species of interest, we reviewed some floral traits to hypothesise what they may mean for bat pollination of the genus.

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The Australian elapid snake radiation (Hydrophiinae) has evolved in the absence of competition from other advanced snakes. This has resulted in ecological specialisation in Australian elapids and the potential for venom proteomes divergent to other elapids. We characterised the venom of the Australian elapid Vermicella annulata (eastern bandy bandy).

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Snake venoms consist of highly biologically active proteins and peptides that are responsible for the lethal physiological effects of snakebite envenomation. In order to guide the development of targeted antivenom strategies, comprehensive understanding of venom compositions and in-depth characterisation of various proteoforms, often not captured by traditional bottom-up proteomic workflows, is necessary. Here, we employ an integrated 'omics' and intact mass spectrometry (MS)-based approach to profile the heterogeneity within the venom of the forest cobra (Naja melanoleuca), adopting different analytical strategies to accommodate for the dynamic molecular mass range of venom proteins present.

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Article Synopsis
  • Researchers have developed a method to activate unreactive carbon-hydrogen bonds in chemical synthesis.
  • They achieved this by engineering a thermostable enzyme that transforms fatty acids through hydroxylation.
  • By modifying a specific part of the enzyme, they enabled it to use hydrogen peroxide for efficient oxidation of C-H bonds at temperatures ranging from room temperature to 90 °C.
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Specialised microbial communities colonise the surface of gold particles in soils/sediments, and catalyse gold dissolution and re-precipitation, thereby contributing to the environmental mobility and toxicity of this 'inert' precious metal. We assessed the proteomic and physiological response of Serratia proteamaculans, the first metabolically active bacterium enriched and isolated directly from natural gold particles, when exposed to toxic levels of soluble Au (10 μM). The results were compared to a metal-free blank, and to cultures exposed to similarly toxic levels of soluble Cu (0.

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Proteomics, the temporal study of proteins expressed by an organism, is a powerful technique that can reveal how organisms respond to biological perturbations, such as disease and environmental stress. Yet, the use of proteomics for addressing ecological questions has been limited, partly due to inadequate protocols for the sampling and preparation of animal tissues from the field. Although RNAlater is an ideal alternative to freezing for tissue preservation in transcriptomics studies, its suitability for the field could be more broadly examined.

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Ortho-phthalaldehyde (OPA) is used as a high-level disinfectant for reusable medical devices in healthcare settings. The ACGIH recently adopted a Threshold Limit Value-Surface Limit (TLV-SL; 25 µg/100 cm2) for OPA surface contamination to prevent induction of dermal and respiratory sensitization following dermal exposure. However, there is no current validated method to measure OPA surface contamination.

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Anthocyanins are a subclass of plant-derived flavonoids that demonstrate immense structural heterogeneity which is challenging to capture in complex extracts by traditional liquid chromatography-mass spectrometry (MS)-based approaches. Here, we investigate direct injection ion mobility-MS as a rapid analytical tool to characterize anthocyanin structural features in red cabbage () extracts. Within a 1.

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Inverse agonists of peroxisome proliferator activated receptor γ (PPARγ) have emerged as safer alternatives to full agonists for their reduced side effects while still maintaining impressive insulin-sensitizing properties. To shed light on their molecular mechanism, we characterized the interaction of the PPARγ ligand binding domain with SR10221. X-ray crystallography revealed a novel binding mode of SR10221 in the presence of a transcriptionally repressing corepressor peptide, resulting in much greater destabilization of the activation helix, H12, than without corepressor peptide.

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The cytochrome P450 (CYP) superfamily of heme monooxygenases has demonstrated ability to facilitate hydroxylation, desaturation, sulfoxidation, epoxidation, heteroatom dealkylation, and carbon-carbon bond formation and cleavage (lyase) reactions. Seeking to study the carbon-carbon cleavage reaction of α-hydroxy ketones in mechanistic detail using a microbial P450, we synthesized α-hydroxy ketone probes based on the physiological substrate for a well-characterized benzoic acid metabolizing P450, CYP199A4. After observing low activity with wild-type CYP199A4, subsequent assays with an F182L mutant demonstrated enzyme-dependent C-C bond cleavage toward one of the α-hydroxy ketones.

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Polyamines and polyamine-containing metabolites are involved in many cellular processes related to bacterial cell growth and survival. In , the bifunctional enzyme glutathionylspermidine synthetase/amidase (GspSA) controls the production of glutathionylspermidine, which has a protective role against oxidative stress. also encodes two enzymes with homology to the synthetase domain of GspSA, YgiC, and YjfC; however, these do not catalyze the formation of glutathionylspermidine, and their catalytic function remained unknown.

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Protein aggregation is now recognized as a generic and significant component of the protein energy landscape. Occurring through a complex and dynamic pathway of structural interconversion, the assembly of misfolded proteins to form soluble oligomers and insoluble aggregates remains a challenging topic of study, both in vitro and in vivo. Since the etiology of numerous human diseases has been associated with protein aggregation, and it has become a field of increasing importance in the biopharmaceutical industry, the biophysical characterization of protein misfolded states and their aggregation mechanisms continues to receive increased attention.

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Alzheimer's disease (AD) is an insidious disease. Its distinctive pathology forms over a considerable length of time without symptoms. There is a need to detect this disease, before even subtle changes occur in cognition.

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Mucin 1 is a transmembrane glycoprotein which overexpresses cancer-specific epitopes (MUC1-CE) on pancreatic ductal adenocarcinoma (PDAC) cells. As PDAC is a low survival and highly aggressive malignancy, developing radioimmunoconjugates capable of targeting MUC1-CE could lead to improvements in PDAC outcomes. The aim of this study was to develop and perform preliminary testing of diagnostic and therapeutic radioimmunoconjugates for PDAC using an anti-MUC1 antibody, C595.

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Enzymes involved in Staphylococcus aureus amino acid metabolism have recently gained traction as promising targets for the development of new antibiotics, however, not all aspects of this process are understood. The ATP-grasp superfamily includes enzymes that predominantly catalyze the ATP-dependent ligation of various carboxylate and amine substrates. One subset, ʟ-amino acid ligases (LALs), primarily catalyze the formation of dipeptide products in Gram-positive bacteria, however, their involvement in S.

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The deposition of α-synuclein (αS) aggregates in the gut and the brain is ever present in cases of Parkinson's disease. While the central non-amyloidogenic-component (NAC) region of αS plays a critical role in fibrilization, recent studies have identified a specific sequence from within the N-terminal region (NTR, residues 36-42) as a key modulator of αS fibrilization. Due to the lack of effective therapeutics which specifically target αS aggregates, we have developed a strategy to prevent the aggregation and subsequent toxicity attributed to αS fibrilization utilizing NTR targeting peptides.

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