Biochem Biophys Res Commun
January 2025
The partition coefficient of human serum albumin (HSA) was analyzed in the PEG600-Dex70, 0.15 M NaCl/KCl in 0.01 M Na/K phosphate buffer, pH 7.
View Article and Find Full Text PDFThe partition behavior of single and double-point mutants of bacteriophage T4 lysozyme (T4 lysozyme) and staphylococcal nuclease A was examined in different aqueous two-phase systems (ATPSs) and studied by Solvent Interaction Analysis (SIA). Additionally, the solvent accessible surface area (SASA) of modeled mutants of both proteins was calculated. The in silico calculations and the in vitro analyses of the staphylococcal nuclease and T4 lysozyme mutants correlate, indicating that the partition analysis in ATPSs provides a valid descriptor (SIA signature) covering various protein features, such as structure, structural dynamics, and conformational stability.
View Article and Find Full Text PDFThis review covers the analytical applications of protein partitioning in aqueous two-phase systems (ATPSs). We review the advancements in the analytical application of protein partitioning in ATPSs that have been achieved over the last two decades. Multiple examples of different applications, such as the quality control of recombinant proteins, analysis of protein misfolding, characterization of structural changes as small as a single-point mutation, conformational changes upon binding of different ligands, detection of protein-protein interactions, and analysis of structurally different isoforms of a protein are presented.
View Article and Find Full Text PDFThe southern coast of Africa is one of the few places in the world where water temperatures are predicted to cool in the future. This endemism-rich coastline is home to two sister species of kelps of the genus Ecklonia maxima and Ecklonia radiata, each associated with specific thermal niches, and occuring primarily on opposite sides of the southern tip of Africa. Historical distribution records indicate that E.
View Article and Find Full Text PDFThe emergence of phase separation in both intracellular biomolecular condensates (membrane-less organelles) and aqueous two-phase systems (ATPS) relies on the formation of immiscible water-based phases/domains. The solvent properties and arrangement of hydrogen bonds within these domains have been shown to differ and can be modulated with the addition of various inorganic salts and osmolytes. The naturally occuring osmolyte, trimethylamine--oxide (TMAO), is well established as a biological condensate stabilizer whose presence results in enhanced phase separation of intracellular membrane-less compartments.
View Article and Find Full Text PDFBiochem Biophys Res Commun
March 2024
The hydrophobicity of solutes measures the intensity of a solute's interaction with aqueous environment. The aqueous environment may change with its composition, leading to changes in its solvent properties largely characterized by polarity. As a result, the relative hydrophobicity of a solute is a function of the solute structure and the properties of the water-based solvent determined by the total composition of the aqueous phase.
View Article and Find Full Text PDFIntroduction: Non-muscle invasive bladder cancer (NMIBC) is a frequently diagnosed neoplasm, which is typically managed with transurethral resection of bladder tumor (TURBT) eventually followed by intravesical therapies. Bacillus Calmette-Guérin (BCG) is used as first-line adjuvant treatment in high- (HR) and intermediate-risk (IR) NMIBC, although, in the latter, mitomycin C (MMC) may also be used. Multiple limitations to the use of BCG encouraged the search for therapeutic alternatives.
View Article and Find Full Text PDFIntroduction Cancer patients on active treatment are at increased risk of developing coronavirus disease 2019 (COVID-19), making effective immunization of the utmost importance. However, the effectiveness of vaccination in this population is still unclear. This study aims to evaluate the response against COVID-19 in a cohort of patients with active cancer under immunosuppressive therapy.
View Article and Find Full Text PDFLiquid-liquid phase separation underlies the formation of membrane-less organelles inside living cells. The mechanism of this process can be examined using simple aqueous mixtures of two or more solutes, which are able to phase separate at specific concentration thresholds. This work presents the first experimental evidence that mesoscopic changes precede visually detected macroscopic phase separation in aqueous mixtures of two polymers and a single polymer and salt.
View Article and Find Full Text PDFThis work presents the first evidence that dissolved globular proteins change the arrangement of hydrogen bonds in water, with different proteins showing quantitatively different effects. Using ATR-FTIR (attenuated total reflection-Fourier transform infrared) spectroscopic analysis of OH-stretch bands, we obtain quantitative estimates of the relative amounts of the previously reported four subpopulations of water structures coexisting in a variety of aqueous solutions. Where solvatochromic dyes can measure the properties of solutions of non-ionic polymers, the results correlate well with ATR-FTIR measurements.
View Article and Find Full Text PDFRenal cell carcinoma (RCC) comprises a highly heterogeneous group of kidney tumours built upon distinct genetic- and epigenetic-driven mechanisms and molecular pathways. Therefore, responsiveness to treatment is considerably variable across patients, adding an extra layer of complexity to the already challenging therapeutic decision process. The last decade brought an unprecedented shift in the medical approach to advanced or metastatic RCC; in fact, immunotherapy-based combinations have significantly transformed the therapeutic arsenal and clinical outcomes of these patients.
View Article and Find Full Text PDFAnalysis by attenuated total reflection-Fourier transform infrared spectroscopy shows that each coexisting phase in aqueous two-phase systems has a different arrangement of hydrogen bonds. Specific arrangements vary for systems formed by different solutes. The hydrogen bond arrangement is shown to correlate with differences in hydrophobic and electrostatic properties of the different phases of five specific systems, four formed by two polymers and one by a single polymer and salt.
View Article and Find Full Text PDFBackground: Triple negative breast cancer (TNBC) has the worst prognosis amongst all subtypes. Studies have shown that the achievement of pathologic complete response in the breast and axilla correlates with improved survival. The aim of this study was to identify clinical or pathological features of real-life TNBC patients with a higher risk of early relapse.
View Article and Find Full Text PDFAnalysis of the partition coefficients of small organic compounds and proteins in different aqueous two-phase systems under widely varied ionic compositions shows that logarithms of partition coefficients for any three compounds or proteins or two organic compounds and one protein are linearly interrelated, although for protein(s) there are ionic compositions when the linear fit does not hold. It is suggested that the established interrelationships are due to cooperativity of different types of solute-solvent interactions in aqueous media. This assumption is confirmed by analysis of distribution coefficients of various drugs in octanol-buffer systems with varied ionic compositions of the buffer.
View Article and Find Full Text PDFIn haplodiplontic lineages, sexual reproduction occurs in haploid parents without meiosis. Although widespread in multicellular lineages such as brown algae (Phaeophyceae), haplodiplontic gametogenesis has been little studied at the molecular level. We addressed this by generating an annotated reference transcriptome for the gametophytic phase of the sugar kelp, Saccharina latissima.
View Article and Find Full Text PDFSimple field tests such as the Timed Up and Go test (TUG) and 30 s Chair Stand test are commonly used to evaluate physical function in the elderly, providing crude outcome measures. Using an automatic chronometer, it is possible to obtain additional kinematic parameters that may lead to obtaining extra information and drawing further conclusions. However, there is a lack of studies that evaluate the test-retest reliability of these parameters, which may help to judge and interpret changes caused by an intervention or differences between populations.
View Article and Find Full Text PDFIt is here reported a new concept based on solvatochromism to distinguish structurally similar compounds in aqueous solutions by the analysis of the stabilization of electronic excited states. The sensitivity of this approach to differentiate similar organic compounds, such as structural isomers or compound differing in the number of methylene groups, or proteins with conformational changes induced by being or not bound to cofactors, differing in two amino acids substitutions, or differing in their glycosylation profile, is demonstrated. The sensitivity of the proposed approach, based on the solvatochromic method, opens the path to its use as an auxiliary analytical tool in biomedical diagnosis/prognosis or in quality control of biologic-based drugs.
View Article and Find Full Text PDFHuman activities such as trade and transport have increased considerably in the last decades, greatly facilitating the introduction and spread of non-native species at a global level. In the Iberian Peninsula, , a small euryhaline coastal fish with short dispersal, was found for the first time in the mid-1970s. Since then, has undergone range expansions, colonizing the southern region of Portugal, southwestern coast of Spain and the Ebro Delta in the Mediterranean Sea.
View Article and Find Full Text PDFIn the past decade, the remarkable potential of ionic-liquid-based aqueous biphasic systems (IL-based ABSs) to extract and purify a large range of valued-added biocompounds has been demonstrated. However, the translation of lab-scale experiments to an industrial scale has been precluded by a poor understanding of the molecular-level mechanisms ruling the separation or partition of target compounds between the coexisting phases. To overcome this limitation, we carried out a systematic evaluation of specific interactions, induced by ILs and several salts used as phase-forming components, and their impact on the partition of several solutes in IL-based ABSs.
View Article and Find Full Text PDFExcessive use of plastics in daily life and the inappropriate disposal of plastic products are severely affecting wildlife species in both coastal and aquatic environments. Birds are top-predators, exposed to all threats affecting their environments, making them ideal sentinel organisms for monitoring ecosystems change. We set a baseline assessment of the prevalence of marine plastic litter affecting multi-species populations of aquatic birds in southern Portugal.
View Article and Find Full Text PDFAlthough highly relevant to a priori select adequate solvents for a given application, the determination of the hydrogen-bond acidity or proton donor ability of aqueous solutions of ionic liquids is a difficult task due to the poor solubility of the commonly used probes in aqueous media. In this work, we demonstrate the applicability of the pyridine-N-oxide probe to determine the hydrogen-bond acidity of both neat ionic liquids and their aqueous solutions, based on C NMR chemical shifts, and the suitability of these values to appraise the ability of ionic liquids to form aqueous two-phase systems.
View Article and Find Full Text PDFThe Iberian Peninsula has an extensive record of species displaying strong genetic structure as a result of their survival in isolated pockets throughout the Pleistocene ice ages. We used mitochondrial and nuclear sequence data to analyze phylogeographic patterns in endemic land snails from a valley of central Portugal (Vale da Couda), putatively assigned to , that show an exceptionally narrow distributional range. The genetic survey presented here shows the existence of five main mitochondrial lineages in Vale da Couda that do not cluster together suggesting independent evolutionary histories.
View Article and Find Full Text PDFPartition behavior of adenosine and guanine mononucleotides was examined in aqueous dextran-polyethylene glycol (PEG) and PEG-sodium sulfate two-phase systems. The partition coefficients for each series of mononucleotides were analyzed as a functions of the number of phosphate groups and found to be dependent on the nature of nucleic base and on the type of ATPS utilized. It was concluded that an average contribution of a phosphate group into logarithm of partition coefficient of a mononucleotide cannot be used to estimate the difference between the electrostatic properties of the coexisting phases of ATPS.
View Article and Find Full Text PDFSolvent properties of aqueous media (dipolarity/polarizability, hydrogen bond donor acidity, and hydrogen bond acceptor basicity) were measured in the coexisting phases of Dextran-PEG aqueous two-phase systems (ATPSs) containing .5 and 2.0 M urea.
View Article and Find Full Text PDFPartition behavior of eight small organic compounds and six proteins was examined in poly(ethylene glycol)-8000-sodium sulfate aqueous two-phase systems containing 0.215M NaCl and 0.5M osmolyte (sorbitol, sucrose, TMAO) and poly(ethylene glycol)-10000-sodium sulfate-0.
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