A5087029469- Biochemical and Structural Characterization
- Chemical Synthesis and Analysis
- Glycosylation and Glycoproteins Research
- Ion channel regulation and function
- Nicotinic Acetylcholine Receptors Study
- Peptidase Inhibition and Analysis
- Receptor Mechanisms and Signaling
- Cellular transport and secretion
- Click Chemistry and Applications
- Venomous Animal Envenomation and Studies
- Phytoplasmas and Hemiptera pathogens
- Ubiquitin and proteasome pathways
- Neuroscience and Neuropharmacology Research
- Antimicrobial Peptides and Activities
- Toxin Mechanisms and Immunotoxins
- Monoclonal and Polyclonal Antibodies Research
- Neurobiology and Insect Physiology Research
- Neuropeptides and Animal Physiology
- Biochemical Analysis and Sensing Techniques
- Complement system in diseases
- RNA and protein synthesis mechanisms
- Transgenic Plants and Applications
- Cardiac electrophysiology and arrhythmias
- Coagulation, Bradykinin, Polyphosphates, and Angioedema
- Enzyme Structure and Function
ARC Centre of Excellence for Innovations in Peptide and Protein Science
2020-2024
The University of Queensland
2015-2024
Australian Research Council
2017-2024
Weatherford College
2024
Boehringer Ingelheim (Australia)
2024
Brisbane School of Theology
2020
University of Chicago
2005-2007
Max Planck Institute of Molecular Physiology
2002-2006
Max Planck Society
2005
Institute of Biochemistry
2004
Abstract Cyclotides are diverse plant backbone cyclized peptides that have attracted interest as pharmaceutical scaffolds, but fundamentals of their biosynthetic origin remain elusive. Backbone cyclization is a key enzyme-mediated step cyclotide biosynthesis and confers measure stability on the resultant cyclotide. Furthermore, would be desirable for engineered peptides. Here we report identification four asparaginyl endopeptidases (AEPs), proteases implicated in cyclization, from...
Rab/Ypt guanosine triphosphatases (GTPases) represent a family of key membrane traffic regulators in eukaryotic cells whose function is governed by the diphosphate (GDP) dissociation inhibitor (RabGDI). Using combination chemical synthesis and protein engineering, we generated crystallized monoprenylated Ypt1:RabGDI complex. The structure complex was solved to 1.5 angstrom resolution provides structural basis for ability RabGDI inhibit release nucleotide Rab proteins. Isoprenoid binding...
In this article, we report the total chemical synthesis of human lysozyme. Lysozyme serves as a widespread model system in various fields biochemical research, including protein folding, enzyme catalysis, and amyloidogenesis. The 130-aa wild-type polypeptide chain was assembled from four segments by using native ligation fully convergent fashion. Key to assembly strategy is application recently developed kinetically controlled methodology, which provides efficient control over two peptide...
Abstract Asparaginyl endopeptidases (AEPs) are proteases that have crucial roles in plant defense and seed storage protein maturation. Select AEPs, however, do not function as but transpeptidases (ligases) catalyzing the intra-molecular ligation of peptide termini, which leads to cyclization. These ligase-type AEPs potential biotechnological applications ranging from vitro engineering molecular farming, structural features enabling these enzymes catalyze ligation/cyclization rather than...
Disulfide-rich cyclic peptides have exciting potential as leads or frameworks in drug discovery; however, their use is faced with some synthetic challenges, mainly associated construction of the circular backbone and formation correct disulfides. Here we describe a simple efficient Fmoc solid-phase peptide synthesis (SPPS)-based method for synthesizing disulfide-rich peptides. This approach involves SPPS on 2-chlorotrityl resin, cyclization partially protected solution, cleavage side-chain...
Going pro: The first facile Pro–Cys ligation using a preformed prolyl selenoester is reported (see scheme; P=peptide). In comparative study of peptide selenoesters in native chemical α-selenoesters are shown to be superior acyl donors and result rate enhancements at least two orders magnitude when compared the well-established α-thioesters. This method permits rapid even previously intractable sites, such as Pro-Cys. Detailed facts importance specialist readers published "Supporting...
Loss-of-function mutations of NaV1.7 lead to congenital insensitivity pain, a rare condition resulting in individuals who are otherwise normal except for the inability sense making pharmacological inhibition promising therapeutic strategy treatment pain. We characterized novel mouse model NaV1.7-mediated pain based on intraplantar injection scorpion toxin OD1, which is suitable rapid vivo profiling inhibitors. Intraplantar OD1 caused spontaneous behaviors, were reversed by co-injection with...
Protein ligases of defined substrate specificity are versatile tools for protein engineering. Upon completion the reaction, products currently reported contain amino acid sequence that is recognized by same ligase, resulting in repeated cycles ligation and hydrolysis as competing reactions. Thus, previous efforts to sequentially label proteins at distinct positions required orthogonal specificity. A recombinant Oldenlandia affinis asparaginyl endopeptidase, OaAEP1, promiscuous incoming...
Asparaginyl endopeptidases (AEPs) catalyze the key backbone cyclization step during biosynthesis of plant-derived cyclic peptides. Here, we report identification two AEPs from Momordica cochinchinensis and biochemically characterize MCoAEP2 that catalyzes maturation trypsin inhibitor cyclotides. Recombinantly produced a linear cyclotide precursor (MCoTI-II-NAL) with kcat/Km 620 mM-1 s-1, making it one fastest cyclases reported to date. We show can mediate both N-terminal excision C-terminal...
Abstract Asparaginyl endopeptidases (AEPs) are a class of enzymes commonly associated with proteolysis in the maturation seed storage proteins. However, subset AEPs work preferentially as peptide ligases, coupling release leaving group to formation new bond. These “ligase-type” require only short recognition motifs ligate range targets, making them useful tools and protein engineering for cyclisation peptides or ligation separate into larger products. Here we report recombinant expression,...
Chemoenzymatic protein and peptide modification is a powerful means of generating defined, homogeneous conjugates for range applications. However, the use transpeptidases limited by need to prepare synthetic be ligated, bulky recognition tags remaining in product, inefficient substrate turnover. Here, we report peptide/protein labeling strategy that utilizes promiscuous, engineered transpeptidase irreversibly incorporate diverse, commercially available amines at C-terminal asparagine. To...
Abstract Mambalgins are a novel class of snake venom components that exert potent analgesic effects mediated through the inhibition acid‐sensing ion channels (ASICs). The 57‐residue polypeptide mambalgin‐2 (Ma‐2) was synthesized by using combination solid‐phase peptide synthesis and native chemical ligation. structure synthetic toxin, determined homonuclear NMR, revealed an unusual three‐finger toxin fold reminiscent functionally unrelated toxins. Electrophysiological analysis Ma‐2 on...
Cyclotides are ultra-stable, backbone-cyclized plant defence peptides that have attracted considerable interest in the pharmaceutical industry. This is due to their range of native bioactivities as well ability stabilize other bioactive within framework. However, a hindrance widespread application lack scalable, cost-effective production strategies. Plant-based an attractive, benign option since all biosynthetic steps performed planta. Nonetheless, cyclization non-cyclotide-producing plants...
ABSTRACT Peptides are attracting increasing interest from the pharmaceutical industry because of their specificity and ability to address novel targets, including protein–protein interactions. However, typically they require stabilization for therapeutic applications owing susceptibility degradation by proteases. Advances in chemically synthesize peptides development new side‐chain backbone ligation strategies provide tools stabilize bioactive peptide epitopes. Two such epitopes LyP1, a nine...
Significance Ribosomally synthesized and post-translationally modified peptides are natural products that hold great promise for a range of medical biotechnological applications. However, the cost-effective heterologous production these is hampered by poor understanding their biosynthesis. Cyclotides, plant-derived, disulfide-knotted, head-to-tail cyclic peptides, exhibit exceptional stability amenability amino acid substitutions insertions. Although much effort has been invested toward...
Voltage-gated sodium (Na
Scorpion α-toxins are invaluable pharmacological tools for studying voltage-gated sodium channels, but few structure–function studies have been undertaken due to their challenging synthesis. To address this deficiency, we report a chemical engineering strategy based upon native ligation. The synthesis of α-toxin OD1 was achieved by ligation three unprotected peptide segments. A high resolution X-ray structure (1.8 Å) synthetic showed the typical βαββ fold and revealed important...
Incorporation of unnatural amino acids (uAAs) via codon reassignment is a powerful approach for introducing novel chemical and biological properties to synthesized polypeptides. However, the site-selective incorporation multiple uAAs into polypeptides hampered by limited number reassignable nonsense codons. This challenge addressed in current work developing Escherichia coli vitro translation system depleted specific endogenous tRNAs. The translational activity this dependent on addition...
The interaction between the cell-cell adhesion proteins CD2 and CD58 plays a crucial role in lymphocyte recruitment to inflammatory sites, inhibitors of this have potential as immunomodulatory drugs autoimmune diseases. Peptides from domain were designed inhibit CD2:CD58 interactions. To improve stability peptides, β-sheet epitopes region implicated recognition grafted into cyclic peptide frameworks sunflower trypsin inhibitor rhesus theta defensin. multicyclic peptides evaluated for their...
ABSTRACT The plant defensin NaD1 is a potent antifungal molecule that also targets tumor cells with high efficiency. We examined the features of contribute to these two activities by producing series chimeras NaD2, has relatively poor activity against fungi and no cells. All defensins have common tertiary structure known as cysteine-stabilized α-β motif which consists an α helix triple-stranded β-sheet stabilized four disulfide bonds. were produced replacing loops 1 7, sequences between each...
Voltage-gated sodium channels are critical for peripheral sensory neuron transduction and have been implicated in a number of painful painless disorders. The β-scorpion toxin, Cn2, is selective NaV 1.6 dorsal root ganglion neurons. plays an essential role neurons, specifically at the distal terminals mechanosensing fibres innervating skin colon. activation also leads to enhanced response mechanical stimulus vivo. This works highlights use toxins elucidating pain pathways moreover importance...