Search

This paper addresses the need of a house rental model in Townsville, Australia. It then describes two models developed for predicting house rental levels. The first model is analytically built upon a priori selected variables and parameters of rental levels. The second model uses an artificial neural network (ANN) as the basis for rent prediction. Issues in model development and evaluation are discussed. A comparison of the two models indicates that the analytical model performs better than the neural network model.

In most instances, the usual fastness of protein unfolding events hinders determining changes in secondary structures associated with this process because these determinations rely on the recording of high-resolution circular dichroism (CD) spectra. In this work, far-UV CD spectra, recorded at ten-minute intervals, were used to evaluate the time course followed by four classes of secondary structures in the slow temperature-induced unfolding of yeast triosephosphate isomerase (yTIM) under distinct pH conditions. CONTIN-LL and SELCON3 algorithms were used for the deconvolution of spectra. Both algorithms furnished helix and unordered structure contents that changed according to first-order kinetics, agreeing with the behavior shown by CD data at specific wavelengths. Analyses of unfolded yTIM spectra, using a dataset that includes spectra of unfolded proteins and either one of the two algorithms, clearly showed a more unordered protein structure at high pH; this finding was corroborated with analysis of the difference spectra. Molecular dynamics (MD) simulations performed with AMBER and OPLS force fields resulted in more extensive loss of helices and gain in coils at high pH, in agreement with spectroscopic results. However, structural differences between low- and high-pH unfolded yTIM were relatively small. Comparison of results from CD and MD thus point to the need of fine-tuning of MD procedures., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Mutations in the LKB1 (also known as STK11 ) tumor suppressor are the third most frequent genetic alteration in non-small cell lung cancer (NSCLC). LKB1 encodes a serine/threonine kinase that directly phosphorylates and activates 14 AMPK family kinases ("AMPKRs"). The function of many of the AMPKRs remains obscure, and which are most critical to the tumor-suppressive function of LKB1 remains unknown. Here, we combine CRISPR and genetic analysis of the AMPKR family in NSCLC cell lines and mouse models, revealing a surprising critical role for the SIK subfamily. Conditional genetic loss of Sik1 revealed increased tumor growth in mouse models of Kras -dependent lung cancer, which was further enhanced by loss of the related kinase Sik3 . As most known substrates of the SIKs control transcription, gene-expression analysis was performed, revealing upregulation of AP1 and IL6 signaling in common between LKB1- and SIK1/3-deficient tumors. The SIK substrate CRTC2 was required for this effect, as well as for proliferation benefits from SIK loss. SIGNIFICANCE: The tumor suppressor LKB1/STK11 encodes a serine/threonine kinase frequently inactivated in NSCLC. LKB1 activates 14 downstream kinases in the AMPK family controlling growth and metabolism, although which kinases are critical for LKB1 tumor-suppressor function has remained an enigma. Here we unexpectedly found that two understudied kinases, SIK1 and SIK3, are critical targets in lung cancer. This article is highlighted in the In This Issue feature, p. 1469 ., (©2019 American Association for Cancer Research.)

Titanium(iv) bis(ammonium lactate)dihydroxide (TiBALDH) is a commercially available reagent frequently used to synthesize TiO 2 . Particularly, for the biomimetic synthesis of TiO 2 , TiBALDH is the preferred precursor because it can be mixed in aqueous solutions with no apparent hydrolysis or condensation reactions. Thus, proteins or other biomolecules can be used as a template in aqueous systems for the synthesis of TiO 2 from TiBALDH. Nevertheless, there is evidence that TiBALDH is in equilibrium with TiO 2 , and even, the principal structure of the complex has been suggested as [Ti 4 O 4 (lactate) 8 ] 8- . Since that chemical equilibrium depends on the polarity of the solvent, in this work we explored a diversity of media to test the chemical stability of TiBALDH and its equilibrium with TiO 2 at room temperature. TiBALDH (2.078 M) contains particles of 18.6 ± 7.3 nm in size, if it is diluted with deionized water, the particles reach a size of 5.2 ± 1.7 nm, which suggest that intermolecular interactions form polymers of titanium lactate complexes reversibly, reaching equilibrium after 10 hours. Typical buffer systems were tested; TiBALDH reacted rapidly only with phosphate groups, even if the source came from DNA. Therefore, phosphate buffer must be avoided in biomineralization TiO 2 synthesis. In solutions of TiBALDH at basic pH, condensation reactions are promoted to form a gel containing anatase nanoparticles, but if the solutions are acidic, monodisperse anatase nanoparticles of ∼5 nm were observed. The results show that the commercial reagent TiBALDH contains many species of titanium lactate complexes in equilibrium with TiO 2 , and it is affected by the concentration, time, pH, and several ions. This peculiar behavior must be taken into account when this precursor is used and it could be useful to develop novel synthesis routes of macrostructures with biomolecules in aqueous systems., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Human cystatin C (HCC) binds and inhibits all types of cysteine proteases from the papain family, including cathepsins (a group of enzymes that participate in a variety of physiological processes), which are some of its natural targets. The affinities of diverse proteases for HCC, expressed as equilibrium binding constants (K b ), range from 10 6 to 10 14  M -1 . Isothermal titration calorimetry (ITC) is one of the most useful techniques to characterize the thermodynamics of molecular associations, making it possible to dissect the binding free energy into its enthalpic and entropic components. This information, together with the structural changes that occur during the different associations, could enable better understanding of the molecular basis of affinity. Notwithstanding the high sensitivity of modern calorimeters, ITC requires protein concentrations in at least the 10-100 μM range to obtain reliable data, and it is known that HCC forms oligomers in this concentration range. We present herein a comparative study of the structural, thermal stability, and oligomerization properties of HCC and its stabilized variant (sHCC) L47C/G69C (which possesses an additional disulfide bridge) as well as their binding thermodynamics to the protease chymopapain, analyzed by ITC. The results show that, because sHCC remains monomeric, it is a better reporter than wild-type HCC to characterize the thermodynamics of binding to cysteine proteases.

AMPK, a conserved sensor of low cellular energy, can either repress or promote tumor growth depending on the context. However, no studies have examined AMPK function in autochthonous genetic mouse models of epithelial cancer. Here, we examine the role of AMPK in murine Kras G12D -mediated non-small-cell lung cancer (NSCLC), a cancer type in humans that harbors frequent inactivating mutations in the LKB1 tumor suppressor-the predominant upstream activating kinase of AMPK and 12 related kinases. Unlike LKB1 deletion, AMPK deletion in Kras G12D lung tumors did not accelerate lung tumor growth. Moreover, deletion of AMPK in Kras G12D p53 f/f tumors reduced lung tumor burden. We identified a critical role for AMPK in regulating lysosomal gene expression through the Tfe3 transcription factor, which was required to support NSCLC growth. Thus, AMPK supports the growth of Kras G12D -dependent lung cancer through the induction of lysosomes, highlighting an unrecognized liability of NSCLC., (Copyright © 2018 Elsevier Inc. All rights reserved.)

A frequent outcome in differential scanning calorimetry (DSC) experiments carried out with large proteins is the irreversibility of the observed endothermic effects. In these cases, DSC profiles are analyzed according to methods developed for temperature-induced denaturation transitions occurring under kinetic control. In the one-step irreversible model (native → denatured) the characteristics of the observed single-peaked endotherm depend on the denaturation enthalpy and the temperature dependence of the reaction rate constant, k. Several procedures have been devised to obtain the parameters that determine the variation of k with temperature. Here, we have elaborated on one of these procedures in order to analyze more complex DSC profiles. Synthetic data for a heat capacity curve were generated according to a model with two sequential reactions; the temperature dependence of each of the two rate constants involved was determined, according to the Eyring's equation, by two fixed parameters. It was then shown that our deconvolution procedure, by making use of heat capacity data alone, permits to extract the parameter values that were initially used. Finally, experimental DSC traces showing two and three maxima were analyzed and reproduced with relative success according to two- and four-step sequential models., (Copyright © 2016 Elsevier Inc. All rights reserved.)

We report the synthesis of Bi nanoparticles (Bi NPs) using the M13 phage as scaffold. The p8 protein of the phage is functionalized with thiol groups of different lengths, and these thiolated regions act as nucleation centers for Bi(3+) ions. The size distribution, shape, and resilience to oxidation of the Bi NPs depend on the length of the thiol group used. The NPs are characterized by high resolution transmission electron microscopy, Raman, and IR spectroscopies, matrix assisted laser desorption/ionization, and optical absorption. These results show that the nanoparticles are crystalline and have a typical diameter of ∼3.0 nm. The method of preparation presented here is reproducible and implies "greener" conditions than those reported elsewhere. To the best of our knowledge, this is the first report of bismuth nanoparticles synthesized by a biomineralization method.

By taking advantage of the physical and chemical properties of the M13 bacteriophage, we have used this virus to synthesize mesoporous silica structures. Major coat protein p8 was chemically modified by attaching thiol groups. As we show, the resulting thiolated phage can be used as a biotemplate able to direct the formation of mesoporous silica materials. Simultaneously, this thiol functionality acts as an anchor for binding metal ions, such as Au(3+) and Pt(4+), forming reactive M13-metal ionic complexes which evolve into metal nanoparticles (NPs) trapped in the mesoporous network. Interestingly, Au(3+) ions are reduced to Au(0) NPs by the protein residues without requiring an external reducing agent. Likewise, silica mesostructures decorated with Au and Pt NPs are prepared in a one-pot synthesis and characterized using different techniques. The obtained results allow us to propose a mechanism of formation. In addition, gold-containing mesoporous structures are tested for the reduction of 4-nitrophenol (4-NP) and methylene blue (MB) in the presence of NaBH4. Although all of the gold-containing catalysts exhibit catalytic activity, those obtained with thiolated phages present a better performance than that obtained with M13 alone. This behavior is ascribed to the position of the Au NPs, which are partially embedded in the wall of the final mesostructures.

We report the heptapeptide-mediated biomineralization of titanium dioxide nanoparticles from titanium alkoxides. We evaluated the influence of pH on the biomineralized products and found that nanostructured TiO2 was formed in the absence of external ions (water only) at pH ~ 6.5. Several variants (mutants) of the peptides with different properties (i.e., different charges, isoelectric points (pIs), and sequences) were designed and tested in biomineralization experiments. Acid-catalyzed experiments were run using the H1 (HKKPSKS) peptide at room temperature, which produced anatase nanoparticles (~5 nm in size) for the first time via a heptapeptide and sol-gel approach. In addition, the peptide H1 was used to synthesize SiO2 nanoparticles. The influence of the pH and the added ions were monitored: at higher pH levels (8-9), SiO2 nanoparticles (20-30 nm in size) were obtained. In addition, whereas borate and Tris ions allowed the formation of colloidal systems, phosphate ions were unable to produce sols. The results presented here demonstrate that biomineralization depends on the sequence and charge of the peptide, and ions in solution can optimize the formation of nanostructures.