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Olympic Dam is a world-class IOCG (iron-oxide copper gold) deposit located in South Australia and is the flagship deposit for the IOCG deposit-style. Limited seismic work has been completed on this deposit style, motivating the completion of a 3D seismic feasibility study to determine the ability of the reflection seismic method to meet imaging objectives in this complex brecciated geology. A 3D physical property model was built at 10 m resolution using representative local density variance, and 50 Hz wavefield equation based acoustic records were generated. Representative ambient and coherent noise was added to records to simulate realistic data, and processing was completed using RTM (reverse time migration). Numerous scenarios related to seismic survey design, acquisition parameters, and in-situ geology were tested, allowing investigation of the impact of IOCG breccias on seismic imaging, identification of key risks and optimised parameters that could help successfully image this geology., Open-Access Online Publication: May 29, 2023

The first sparse 3D hardrock seismic survey at Olympic Dam (OD) mine was acquired during June to August of 2022. OD is an Iron-Oxide Copper Gold (IOCG) deposit in South Australia and is one of the largest known copper deposits and the single largest uranium deposit in the world. This property-wide seismic survey at OD was designed to answer four technical questions defined in a 3D seismic feasibility study focused on seismic imaging of IOCG-type geology, as well as identify operational challenges with seismic acquisition across a busy mine site. This adaptation of modern-day hardrock seismic methodologies over an ore deposit represents the largest to date of any hardrock seismic application for BHP and will accelerate resource characterisation and the targeting of deep drillholes. Outcomes of this sparse 3D survey inform several decision points for a full 3D seismic survey at OD., Open-Access Online Publication: May 29, 2023

In support of a deep drilling program to define the lower extents of Fe-oxide alteration and potential sulfide mineralisation, BHP undertook a feasibility study to determine the viability of conducting Sparse and Full 3D hardrock seismic surveys of the Olympic Dam deposit. P-wave velocity measurements were systematically collected, via hand held instruments, on diamond drill core spanning the spectrum of alteration and brecciation styles present across the breccia complex and into the granite host rock. The purpose of this data was to provide measured seismic velocities into the feasibility modelling and subsequent processing and interpretation of the seismic surveys. Prior to data collection several questions were posed to focus the data collection. These questions included 1) what are the velocity (Vp) values of the various alteration and brecciation styles present in the deposit, 2) can Vp be used to directly detect sulfide mineralisation, and 3) are the Vp contrasts across faults great enough to detect the faults? The results of the velocity measurement study, correlated with bulk dry density, magnetic susceptibility, Fe-oxide alteration intensity and sulfide mineralisation clearly demonstrate that 1) disseminated sulfide mineralisation is likely not detectable via Vp measurements, 2) hematite breccias when in fault contact with granite and granite-breccias have enough of a Vp contrast to be detected in seismic surveys, 3) porosity varies significantly within the breccias and does influence Vp, and 4) Vp contrasts in the granites surrounding the deposit are too low to be used for vectoring to Fe-oxide alteration. Geochemical and mineralogical data combined with geological observations provides a powerful dataset when unravelling the characteristics of complex ore deposits. One of the major insights from this study, is that when petrophysical data (such as Vp, magnetic susceptibility, and bulk dry density) are also used, the multitude of possible geological interpretations can be significantly reduced., Open-Access Online Publication: May 29, 2023

A method to efficiently immobilize and partition large quantities of microbeads in an array format in microfabricated polydimethylsiloxane (PDMS) cassette for high-throughput in situ releasable solution-phase cell-based screening of one-bead-one-compound (OBOC) combinatorial libraries is described. Commercially available Jeffamine triamine T-403 (∼440 Da) was derivatized such that two of its amino groups were protected by Fmoc and the remaining amino group capped with succinic anhydride to generate a carboxyl group. This resulting tri-functional hydrophilic polymer was then sequentially coupled two times to the outer layer of topologically segregated bilayer TentaGel (TG) beads with solid phase peptide synthesis chemistry, resulting in beads with increased loading capacity, hydrophilicity and porosity at the outer layer. We have found that such bead configuration can facilitate ultra high-throughput in situ releasable solution-phase screening of OBOC libraries. An encoded releasable OBOC small molecule library was constructed on Jeffamine derivatized TG beads with library compounds tethered to the outer layer via a disulfide linker and coding tags in the interior of the beads. Compound-beads could be efficiently loaded (5-10 minutes) into a 5 cm diameter Petri dish containing a 10,000-well PDMS microbead cassette, such that over 90% of the microwells were each filled with only one compound-bead. Jurkat T-lymphoid cancer cells suspended in Matrigel® were then layered over the microbead cassette to immobilize the compound-beads. After 24 hours of incubation at 37°C, dithiothreitol was added to trigger the release of library compounds. Forty-eight hours later, MTT reporter assay was used to identify regions of reduced cell viability surrounding each positive bead. From a total of about 20,000 beads screened, 3 positive beads were detected and physically isolated for decoding. A strong consensus motif was identified for these three positive compounds. These compounds were re-synthesized and found to be cytotoxic (IC50 50-150 μM) against two T-lymphoma cell lines and less so against the MDA-MB 231 breast cancer cell line. This novel ultra high-throughput OBOC releasable method can potentially be adapted to many existing 96- or 384-well solution-phase cell-based or biochemical assays.

In the one-bead-one-compound (OBOC) combinatorial method, compounds are constructed on bead resin via split-mix library synthesis such that multiple copies of the same compound are displayed on each bead. These libraries are rapidly screened with enzyme-linked colorimetric, fluorescent, radiometric, or whole-cell binding assays. While fluorescence-based probes are powerful tools in OBOC screening, their utility is greatly limited by the intrinsic fluorescence of many commonly used solid supports, (e.g., TentaGel), residual coupling reagents, and library compounds. To overcome this problem, we topologically partitioned TentaGel resin with a thin Fmoc-protected outer layer and an unprotected inner core. The inner core was derivatized with 3-nitro-tyrosine, followed by random peptide library construction. Spectral scans from a confocal microscope showed a dramatic decrease in the autofluorescence of blank beads and OBOC peptide libraries across a broad range of the optical spectrum. The quenching capacity of 3-nitro-tyrosine was also visualized in fluorescent micrographs. Using biotin/streptavidin as a model ligand/receptor system, we demonstrated a marked increase in visibility of three commercially available fluorescent probes binding to quenched beads, and increased feasibility of using a robust and efficient fluorescence-based, bead sorting platform known as COPAS™. These data show that using 3-nitro-tyrosine as an internal quencher greatly enhances the compatibility of fluorescence-based applications and OBOC combinatorial screening.

The AtDi19 (drought-induced) gene family encodes seven hydrophilic proteins that contain two atypical Cys2/His2 (C2H2) zinc finger-like domains that are evolutionarily well-conserved within angiosperms suggesting a conserved and important function. Five of the seven Arabidopsis AtDi19-related:DsRed2 fusion proteins exhibited speckled patterns of localization within the nucleus as shown by transient expression analysis in Arabidopsis protoplasts. In contrast, AtDi19-2:DsRed2 was present in the nucleus and cytoplasm, whereas AtDi19-4:DsRed2 was localized to the nuclear periphery. mRNA expression studies showed that AtDi19 genes are ubiquitously expressed in Arabidopsis tissues, although some differences were observed. In seedlings, RT-PCR analyses showed that AtDi19-1 and AtDi19-3 steady-state transcript amounts were rapidly induced by dehydration, whereas transcript amounts for AtDi19-2 and AtDi19-4 increased in response to high-salt stress. In addition, the mRNA abundance of all the AtDi19-related gene family members was not regulated by ABA. These data, taken together, suggest that several AtDi19-related gene family members may function in ABA-independent, dehydration and salinity stress signaling pathways. However, they may also be regulated by other abiotic stimuli. AtDi19-7, for example, has been implicated in regulating light signaling and responses. Finally, we show that most AtDi19-related proteins are phosphorylated in vitro by calcium-dependent protein kinases suggesting that this post-translational modification may be important for regulating the function of this novel protein family.

Calcium-dependent protein kinases (CDPKs) are sensor-transducer proteins capable of decoding calcium signals in diverse phosphorylation-dependent calcium signaling networks in plants and some protists. Using a novel yeast two-hybrid (YTH) approach with constitutively active and/or catalytically inactive forms of AtCPK11 as bait, we identified AtDi19 as an AtCPK11-interacting protein. AtDi19 is a member of a small family of stress-induced genes. The interaction was confirmed using pull-down assays with in vitro translated AtCPK11 and GST–AtDi19 and localization studies in Arabidopsis protoplasts cotransfected with AtCPK11:GFP and AtDi19:DsRed2 protein fusions. We further showed that the interaction of AtDi19 is specific to both AtCPK4 and AtCPK11, whereas other closely related CPKs from Arabidopsis interacted weakly (e.g., AtCPK12) or did not interact (e.g., AtCPK26, AtCPK5 and AtCPK1) with AtDi19. Deletion analyses showed that a region containing two predicted nuclear localization signals (NLS) and a nuclear export signal (NES) of AtDi19 is essential for interaction with AtCPK11. We further demonstrated that AtDi19 is phosphorylated by AtCPK11 in a Ca2+-dependent manner at Thr105 and Ser107 within the AtDi19 bipartite NLS using in vitro kinase assays. Our data suggest that disruption of the autoinhibitor domain leading to the formation of a constitutively active CDPK may stabilize kinase–substrate interactions without affecting specificity.

Recently platelet-derived growth factor-α-positive cells (PDGFRα+cells), previously called “fibroblast-like” cells, have been described in the muscle layers of the gastrointestinal tract. These cells form networks and are involved in purinergic motor neurotransduction. Examination of colon from mice with enhanced green fluorescent protein (eGFP) driven from the endogenous Pdgfra (PDGFRα-eGFP mice) revealed a unique population of PDGFRα+cells in the mucosal layer of colon. We investigated the phenotype and potential role of these cells, which have not been characterized previously. Expression of PDGFRα and several additional proteins was surveyed in human and murine colonic mucosae by immunolabeling; PDGFRα+cells in colonic mucosa were isolated from PDGFRα-eGFP mice, and the gene expression profile was analyzed by quantitative polymerase chain reaction. We found for the first time that PDGFRα was expressed in subepithelial cells (subepithelial PDGFRα+cells) forming a pericryptal sheath from the base to the tip of crypts. These cells were in close proximity to the basolateral surface of epithelial cells and distinct from subepithelial myofibroblasts, which were identified by expression of α-smooth muscle actin and smooth muscle myosin. PDGFRα+cells also lay in close proximity to varicose processes of nerve fibers. Mouse subepithelial PDGFRα+cells expressed Toll-like receptor genes, purinergic receptor genes, 5-hydroxytryptamine (5-HT) 4 receptor gene, and hedgehog signaling genes. Subepithelial PDGFRα+cells occupy an important niche in the lamina propria and may function in transduction of sensory and immune signals and in the maintenance of mucosal homeostasis.

Cherimolacyclopeptide E (1) is a cyclic hexapeptide obtained from Annona cherimola, reported to be cytotoxic against the KB (human nasopharyngeal carcinoma) cell line. The solid-phase total syntheses of this cyclic peptide and its analogues were accomplished by employing FMOC/tert-butyl-protected amino acids and the Kenner sulfonamide safety-catch linker. The synthetic peptide 1 was found to be weakly cytotoxic against four cell lines (MOLT-4, Jurkat T lymphoma, MDA-MB-231, and KB). Analogues 3 and 7, where glycine at positions 2 and 6 of the parent compound was replaced by Ala, exhibited enhanced cytotoxicity against KB (3, IC50 6.3 μM; 7, IC50 7.8 μM) and MDA-MB-231 breast cancer cells (3, IC50 10.2 μM; 7, IC50 7.7 μM), thereby suggesting possible selective targeting of these cancer cells by these peptides. The spectral data of synthetic peptide 1 was found to be similar to that reported for the natural product. However, a striking difference in biological activity was noted, which warrants the re-evaluation of the original natural product for purity and the existence of conformational differences.

One-bead-one-compound (OBOC) combinatorial library screening has been broadly utilized for the last two decades to identify small molecules, peptides or peptidomimetics targeting variable screening probes such as cell surface receptors, bacteria, protein kinases, phosphatases, proteases etc. In previous screening methods, library beads were suspended in solution and screened against one single probe. Only the positive beads were tracked and isolated for additional screens and finally selected for chemical decoding. During this process, the remaining negative beads were not tracked and discarded. Here we report a novel bead immobilization method such that a bead library array can be conveniently prepared and screened in its entirety, sequentially many times with a series of distinct probes. This method not only allows us to increase the screening efficiency but also permits us to determine the binding profile of each and every library bead against a large number of target receptors. As proof of concept, we serially screened a random OBOC disulfide containing cyclic heptapeptide library with three water soluble dyes as model probes: malachite green, bromocresol purple and indigo carmine. This multiplicative screening approach resulted in a rapid determination of the binding profile of each and every bead respective to each of the three dyes. Beads that interacted with malachite green only, bromocresol purple only, or both indigo carmine and bromocresol purple were isolated, and their peptide sequences were determined with microsequencer. Ultimately, the novel OBOC multiplicative screening approach could play a key role in the enhancement of existing on-bead assays such as whole cell binding, bacteria binding, protein binding, post-translational modifications etc. with increased efficiency, capacity, and specificity.

Calcium-dependent protein kinases (CDPKs) are sensor-transducer proteins capable of decoding calcium signals in diverse phosphorylation-dependent calcium signaling networks in plants and some protists. Using a novel yeast two-hybrid (YTH) approach with constitutively active and/or catalytically inactive forms of AtCPK11 as bait, we identified AtDi19 as an AtCPK11-interacting protein. AtDi19 is a member of a small family of stress-induced genes. The interaction was confirmed using pull-down assays with in vitro translated AtCPK11 and GST-AtDi19 and localization studies in Arabidopsis protoplasts cotransfected with AtCPK11:GFP and AtDi19:DsRed2 protein fusions. We further showed that the interaction of AtDi19 is specific to both AtCPK4 and AtCPK11, whereas other closely related CPKs from Arabidopsis interacted weakly (e.g., AtCPK12) or did not interact (e.g., AtCPK26, AtCPK5 and AtCPK1) with AtDi19. Deletion analyses showed that a region containing two predicted nuclear localization signals (NLS) and a nuclear export signal (NES) of AtDi19 is essential for interaction with AtCPK11. We further demonstrated that AtDi19 is phosphorylated by AtCPK11 in a Ca(2+)-dependent manner at Thr105 and Ser107 within the AtDi19 bipartite NLS using in vitro kinase assays. Our data suggest that disruption of the autoinhibitor domain leading to the formation of a constitutively active CDPK may stabilize kinase-substrate interactions without affecting specificity.