X-ray crystallographic and NMR studies of pantothenate synthetase provide insights into the mechanism of homotropic inhibition by pantoate

The structural basis for the homotropic inhibition of pantothenate synthetase by the substrate pantoate was investigated by X-ray crystallography and high-resolution NMR spectroscopic methods. The tertiary structure of the dimeric N-terminal domain of Escherichia coli pantothenate synthetase, determined by X-ray crystallography to a resolution of 1.7 Å, showed a second molecule of pantoate bound in the ATP-binding pocket. Pantoate binding to the ATP-binding site induced large changes in structure, mainly for backbone and side chain atoms of residues in the ATP binding HXGH(34–37) motif. Sequence-specific NMR resonance assignments and solution secondary structure of the dimeric N-terminal domain, obtained using samples enriched in 2H, 13C, and 15N, indicated that the secondary structural elements were conserved in solution. Nitrogen-15 edited two-dimensional solution NMR chemical shift mapping experiments revealed that pantoate, at 10 mm, bound at these two independent sites. The solution NMR studies unambiguously demonstrated that ATP stoichiometrically displaced pantoate from the ATP-binding site. All NMR and X-ray studies were conducted at substrate concentrations used for enzymatic characterization of pantothenate synthetase from different sources [Jonczyk R & Genschel U (2006) J Biol Chem 281, 37435–37446]. As pantoate binding to its canonical site is structurally conserved, these results demonstrate that the observed homotropic effects of pantoate on pantothenate biosynthesis are caused by competitive binding of this substrate to the ATP-binding site. The results presented here have implications for the design and development of potential antibacterial and herbicidal agents.

Wear Next: An Exploration into the Future of Wearable Technology

Technology is increasingly infiltrating all aspects of our lives and the rapid uptake of devices that live near, on or in our bodies are facilitating radical new ways of working, relating and socialising. This distribution of technology into the very fabric of our everyday life creates new possibilities, but also raises questions regarding our future relationship with data and the quantified self. By embedding technology into the fabric of our clothes and accessories, it becomes ‘wearable’. Such ‘wearables’ enable the acquisition of and the connection to vast amounts of data about people and environments in order to provide life-augmenting levels of interactivity. Wearable sensors for example, offer the potential for significant benefits in the future management of our wellbeing. Fitness trackers such as ‘Fitbit’ and ‘Garmen’ provide wearers with the ability to monitor their personal fitness indicators while other wearables provide healthcare professionals with information that improves diagnosis. While the rapid uptake of wearables may offer unique and innovative opportunities, there are also concerns surrounding the high levels of data sharing that come as a consequence of these technologies. As more ‘smart’ devices connect to the Internet, and as technology becomes increasingly available (e.g. via Wi-Fi, Bluetooth), more products, artefacts and things are becoming interconnected. This digital connection of devices is called The ‘Internet of Things’ (IoT). IoT is spreading rapidly, with many traditionally non-online devices becoming increasingly connected; products such as mobile phones, fridges, pedometers, coffee machines, video cameras, cars and clothing. The IoT is growing at a rapid rate with estimates indicating that by 2020 there will be over 25 billion connected things globally. As the number of devices connected to the Internet increases, so too does the amount of data collected and type of information that is stored and potentially shared. The ability to collect massive amounts of data - known as ‘big data’ - can be used to better understand and predict behaviours across all areas of research from societal and economic to environmental and biological. With this kind of information at our disposal, we have a more powerful lens with which to perceive the world, and the resulting insights can be used to design more appropriate products, services and systems. It can however, also be used as a method of surveillance, suppression and coercion by governments or large organisations. This is becoming particularly apparent in advertising that targets audiences based on the individual preferences revealed by the data collected from social media and online devices such as GPS systems or pedometers. This type of technology also provides fertile ground for public debates around future fashion, identity and broader social issues such as culture, politics and the environment. The potential implications of these type of technological interactions via wearables, through and with the IoT, have never been more real or more accessible. But, as highlighted, this interconnectedness also brings with it complex technical, ethical and moral challenges. Data security and the protection of privacy and personal information will become ever more present in current and future ethical and moral debates of the 21st century. This type of technology is also a stepping-stone to a future that includes implantable technology, biotechnologies, interspecies communication and augmented humans (cyborgs). Technologies that live symbiotically and perpetually in our bodies, the built environment and the natural environment are no longer the stuff of science fiction; it is in fact a reality. So, where next?... The works exhibited in Wear Next_ provide a snapshot into the broad spectrum of wearables in design and in development internationally. This exhibition has been curated to serve as a platform for enhanced broader debate around future technology, our mediated future-selves and the evolution of human interactions. As you explore the exhibition, may we ask that you pause and think to yourself, what might we... Wear Next_? WEARNEXT ONLINE LISTINGS AND MEDIA COVERAGE: http://indulgemagazine.net/wear-next/ http://www.weekendnotes.com/wear-next-exhibition-gallery-artisan/ http://concreteplayground.com/brisbane/event/wear-next_/ http://www.nationalcraftinitiative.com.au/news_and_events/event/48/wear-next http://bneart.com/whats-on/wear-next_/ http://creativelysould.tumblr.com/post/124899079611/creative-weekend-art-edition http://www.abc.net.au/radionational/programs/breakfast/smartly-dressed-the-future-of-wearable-technology/6744374 http://couriermail.newspaperdirect.com/epaper/viewer.aspx RADIO COVERAGE http://www.abc.net.au/radionational/programs/breakfast/wear-next-exhibition-whats-next-for-wearable-technology/6745986 TELEVISION COVERAGE http://www.abc.net.au/radionational/programs/breakfast/wear-next-exhibition-whats-next-for-wearable-technology/6745986 https://au.news.yahoo.com/video/watch/29439742/how-you-could-soon-be-wearing-smart-clothes/#page1

Structural Insights into the acyl-intermediates of plasmodium falciparum fatty acid synthesis pathway; the mechanism of expansion of acyl carrier protein core

Acyl carrier protein (ACP) plays a central role in fatty acid biosynthesis. However, the molecular machinery that mediates its function is not yet fully understood. Therefore, structural studies were carried out on the acyl-ACP intermediates of Plasmodium falciparum using NMR as a spectroscopic probe. Chemical shift perturbation studies put forth a new picture of the interaction of ACP molecule with the acyl chain, namely, the hydrophobic core can protect up to 12 carbon units, and additional carbons protrude out from the top of the hydrophobic cavity. The latter hypothesis stems from chemical shift changes observed in C-alpha and C-beta of Ser-37 in tetradecanoyl-ACP. C-13, N-15-Double-filtered nuclear Overhauser effect (NOE) spectroscopy experiments further substantiate the concept; in octanoyl (C-8)- and dodecanoyl (C-12)-ACP, a long range NOE is observed within the phosphopantetheine arm, suggesting an arch-like conformation. This NOE is nearly invisible in tetradecanoyl (C-14)-ACP, indicating a change in conformation of the prosthetic group. Furthermore, the present study provides insights into the molecular mechanism of ACP expansion, as revealed from a unique side chain-to-backbone hydrogen bond between two fairly conserved residues, Ile-55 HN and Glu-48 O. The backbone amide of Ile-55 HN reports a pK(a) value for the carboxylate, similar to 1.9 pH units higher than model compound value, suggesting strong electrostatic repulsion between helix II and helix III. Charge-charge repulsion between the helices in combination with thrust from inside due to acyl chain would energetically favor the separation of the two helices. Helix III has fewer structural restraints and, hence, undergoes major conformational change without altering the overall-fold of P. falciparum ACP.

An investigation into the thermophysical and rheological properties of nanofluids for solar thermal applications

Considered to be the next generation of heat transfer fluids, nanofluids have been receiving a growing amount of attention in the past decade despite the controversy and inconsistencies that have been reported. Nanofluids have great potential in a wide range of fields, particularly for solar thermal applications. This paper presents a comprehensive review of the literature on the enhancements in thermophysical and rheological properties resulting from experimental works conducted on molten salt nanofluids that are used in solar thermal energy systems. It was found that an increase in specific heat of 10–30% was achieved for most nanofluids and appeared independent of particle size and to an extent mass concentration. The specific heat increase was attributed to the formation of nanostructures at the solid–liquid interface and it was also noted that the aggregation of nanoparticles has detrimental effects on the specific heat increase. Thermal conductivity was also found to increase, though less consistently, ranging from 3% to 35%. Viscosity was seen to increase with the addition of nanoparticles and is dependent on the amount of aggregation of the particles. An in-depth micro level analysis of the mechanisms behind the thermophysical property changes is presented in this paper. In addition, possible trends are discussed relating to current theorised mechanisms in an attempt to explain the behaviour of molten salt nanofluids.

Translating emotional insights into digital channel designs: Opportunities to enhance the airport experience

Purpose The purpose of this study is to identify and understand the emotions behind a passenger’s airport experience and how this can inform digital channel engagements. Design/methodology/approach This study investigates the emotional experience of two hundred (200) passengers’ journeys at an Australian domestic airport. A survey was conducted which implemented the use of Emocards and an interview approach of laddering. The responses were then analysed into attributes, consequences and values. Findings The results indicate that across key stages of the airport (parking, retail, gates and arrivals) passengers had different emotional experiences (positive, negative and neutral). The attributes, consequences and values behind these emotions were then used to propose digital channel content and purpose of various future digital channel engagements. Research limitations/implications By gaining emotional insights airports are able to generate digital channel engagements, which align with passengers’ needs and values rather than internal operational motivations. Theoretical contributions include the development of the Technology Acceptance Model to include emotional drivers as influences in the use of digital channels. Originality/value This research provides a unique method to understand the passengers’ emotional journey across the airport infrastructure and suggest how to better design digital channel engagements to address passenger latent needs.

Engineered protease inhibitors based on sunflower trypsin inhibitor-1 (SFTI-1) provide insights into the role of sequence and conformation in Laskowski mechanism inhibition

Laskowski inhibitors regulate serine proteases by an intriguing mode of action that involves deceiving the protease into synthesizing a peptide bond. Studies exploring naturally occurring Laskowski inhibitors have uncovered several structural features that convey the inhibitor's resistance to hydrolysis and exceptional binding affinity. However, in the context of Laskowski inhibitor engineering, the way that various modifications intended to fine-tune an inhibitor's potency and selectivity impact on its association and dissociation rates remains unclear. This information is important as Laskowski inhibitors are becoming increasingly used as design templates to develop new protease inhibitors for pharmaceutical applications. In this study, we used the cyclic peptide, sunflower trypsin inhibitor-1 (SFTI-1), as a model system to explore how the inhibitor's sequence and structure relate to its binding kinetics and function. Using enzyme assays, MD simulations and NMR spectroscopy to study SFTI variants with diverse sequence and backbone modifications, we show that the geometry of the binding loop mainly influences the inhibitor's potency by modulating the association rate, such that variants lacking a favourable conformation show dramatic losses in activity. Additionally, we show that the inhibitor's sequence (including both the binding loop and its scaffolding) influences its potency and selectivity by modulating both the association and the dissociation rates. These findings provide new insights into protease inhibitor function and design that we apply by engineering novel inhibitors for classical serine proteases, trypsin and chymotrypsin and two kallikrein-related peptidases (KLK5 and KLK14) that are implicated in various cancers and skin diseases.

Insight into the early stages of thermal unfolding of peanut agglutinin by molecular dynamics simulations

Peanut agglutinin is a homotetrameric nonglycosylated protein. The protein has a unique open quaternary structure. Molecular dynamics simulations have been employed follow the atomistic details of its unfolding at different temperatures. The early events of the deoligomerization of the protein have been elucidated in the present study. Simulation trajectories of the monomer as well as those of the tetramer have been compared and the tetramer is found to be substantially more stable than its monomeric counterpart. The tetramer shows retention of most of its.. secondary structure but considerable loss of the tertiary structure at high temperature. e generation of a This observation impies the molten globule-like intermediate in the later stages of deoligomerization. The quaternary structure of the protein has weakened to a large extent, but none of the subunits are separated. In addition, the importance of the metal-binding to the stability of the protein structure has also been investigated. Binding of the metal ions not only enhances the local stability of the metal-ion binding loop, but also imparts a global stability to the overall structure. The dynamics of different interfaces vary significantly as probed through interface clusters. The differences are substantially enhanced at higher temperatures. The dynamics and the stability of the interfaces have been captured mainly by cluster analysis, which has provided detailed information on the thermal deoligomerization of the protein.

Pannus invasion into cartilage and bone in rheumatoid arthritis

Rheumatoid arthritis is the most common of all types of arthritis and despite of intensive research etiology of the disease remains unclear. Distinctive features of rheumatic arthritis comprise continuous inflammation of synovium, in which synovial membrane expands on cartilage leading to pannus tissue formation. Pannus formation, appearance of proteolytic enzymes and osteoclast formation cause articular cartilage and bone destruction, which lead to erosions and permanent joint damage. Proteolytic pathways play major roles in the development of tissue lesions in rheumatoid arthritis. Degradation of extracellular matrix proteins is essential to pannus formation and invasion. Matrix metalloproteinases (MMP) form a large proteolytic enzyme family and in rheumatoid arthritis they contribute to pannus invasion by degrading extracellular matrix and to joint destruction by directly degrading the cartilage. MMP-1 and MMP-3 are shown to be increased during cell invasion and also involved in cartilage destruction. Increase of many cytokines has been observed in rheumatoid arthritis, especially TNF-α and IL-1β are studied in synovial tissue and are involved in rheumatoid inflammation and degradation of cartilage. Underlying bone resorption requires first demineralization of bone matrix with acid secreted by osteoclasts, which exposes the collagen-rich matrix for degradation. Cathepsin K is the best known enzyme involved in bone matrix degradation, however deficiency of this protein in pycnodysostosis patient did not prevent bone erosion and on the contrary pannus tissue invading to bone did not expressed much cathepsin K. These indicate that other proteinases are involved in bone degradation, perhaps also via their capability to replace the role of other enzymes especially in diseases like pycnodysostosis or during medication e.g. using cathepsin K inhibitors. Multinuclear osteoclasts are formed also in pannus tissue, which enable the invasion into underlying bone matrix. Pannus tissue express a receptor activator of nuclear factor kappa B ligand (RANKL), an essential factor for osteoclast differentiation and a disintegrin and a metalloproteinase 8 (ADAM8), an osteoclast-activating factors, involved in formation of osteoclast-like giant cells by promoting fusion of mononuclear precursor cells. The understanding of pannus invasion and degradation of extracellular matrix in rheumatic arthritis will open us new more specific methods to prevent this destructive joint disease.

Free software and the law. Out of the frying pan and into the fire: How shaking up intellectual property suits competition law just fine

Free software is viewed as a revolutionary and subversive practice, and in particular has dealt a strong blow to the traditional conception of intellectual property law (although in its current form could be considered a 'hack' of IP rights). However, other (capitalist) areas of law have been swift to embrace free software, or at least incorporate it into its own tenets. One area in particular is that of competition (antitrust) law, which itself has long been in theoretical conflict with intellectual property, due to the restriction on competition inherent in the grant of ‘monopoly’ rights by copyrights, patents and trademarks. This contribution will examine how competition law has approached free software by examining instances in which courts have had to deal with such initiatives, for instance in the Oracle Sun Systems merger, and the implications that these decisions have on free software initiatives. The presence or absence of corporate involvement in initiatives will be an important factor in this investigation, with it being posited that true instances of ‘commons-based peer production’ can still subvert the capitalist system, including perplexing its laws beyond intellectual property.

Kinetics of Pressureless Infiltration of Al-Mg Melts into Porous Alumina Preforms

Effective “hydrodynamic” radii governing infiltration kinetics of reactive Al-Mg melts into alumina preforms were found to be three orders of magnitude smaller than the average pore size of the packed bed and also smaller compared with the kinetics for a nonreactive system. A sinusoidal capillary model was developed to predict flow kinetics within the packed bed. For the reactive system, two factors were ascribed for additional melt retardation: (1) different intrinsic wettabilities of the two liquids on alumina, thereby leading to significantly different “effective” local contact angles; and (2) local solute depletion from the meniscus, which was incorporated as a time-dependent contact angle.

Inspiration sources for Australian fast fashion design: Tapping into consumer desire

Purpose The research purpose was to identify both the inspiration sources used by fast fashion designers and ways the designers sort information from the sources during the product development process. Design/methodology/approach This is a qualitative study, drawing on semi-structured interviews conducted with the members of the in-house design teams of three Australian fast fashion companies. Findings Australian fast fashion designers rely on a combination of trend data, sales data, product analysis and travel for design development ideas. The designers then use the consensus and embodiment methods to interpret and synthesise information from those inspiration sources. Research limitations/implications The empirical data used in the analysis were limited by interviewing fashion designers within only three Australian companies. Originality/value This research augments knowledge of fast fashion product development, in particular designers’ methods and approaches to product design within a volatile and competitive market.

Insights into Atmospheric Nucleation

Atmospheric aerosol particles have a strong impact on the global climate. A deep understanding of the physical and chemical processes affecting the atmospheric aerosol climate system is crucial in order to describe those processes properly in global climate models. Besides the climatic effects, aerosol particles can deteriorate e.g. visibility and human health. Nucleation is a fundamental step in atmospheric new particle formation. However, details of the atmospheric nucleation mechanisms have remained unresolved. The main reason for that has been the non-existence of instruments capable of measuring neutral newly formed particles in the size range below 3 nm in diameter. This thesis aims to extend the detectable particle size range towards close-to-molecular sizes (~1nm) of freshly nucleated clusters, and by direct measurement obtain the concentrations of sub-3 nm particles in atmospheric environment and in well defined laboratory conditions. In the work presented in this thesis, new methods and instruments for the sub-3 nm particle detection were developed and tested. The selected approach comprises four different condensation based techniques and one electrical detection scheme. All of them are capable to detect particles with diameters well below 3 nm, some even down to ~1 nm. The developed techniques and instruments were deployed in the field measurements as well as in laboratory nucleation experiments. Ambient air studies showed that in a boreal forest environment a persistent population of 1-2 nm particles or clusters exists. The observation was done using 4 different instruments showing a consistent capability for the direct measurement of the atmospheric nucleation. The results from the laboratory experiments showed that sulphuric acid is a key species in the atmospheric nucleation. The mismatch between the earlier laboratory data and ambient observations on the dependency of nucleation rate on sulphuric acid concentration was explained. The reason was shown to be associated in the inefficient growth of the nucleated clusters and in the insufficient detection efficiency of particle counters used in the previous experiments. Even though the exact molecular steps of nucleation still remain an open question, the instrumental techniques developed in this work as well as their application in laboratory and ambient studies opened a new view into atmospheric nucleation and prepared the way for investigating the nucleation processes with more suitable tools.